acceleratedin eden

Eden Tyres and Servicing saw a positive impact on growth after joining Castrol Service Network
Published:  12 November, 2018

Eden Tyres & Servicing is an independent family business. Having opened its first branch in Derby in 1981, Eden Tyres now operates 15 branches across the Midlands.   
    
As one of the first independent workshops to sign up to Castrol Service, all Eden Tyres sites are now part of the network of independent garages in the UK. Here, we look at how the business has benefitted from the technical and business support offered through The Race Group as a member of the Castrol Service Network.

Introducing Castrol Service
Developed by Castrol Oil, Castrol Service aims to create a nationwide network for the UK’s best independent garages. To be eligible to join the scheme, prospective garages must meet set criteria to ensure consistent standards across all centres. There is no associated cost for being part of the network but there is a requirement for the garage to commit to using Castrol Lubricants for 95% of its service work.
    
Once garages have been accepted into the network they benefit from significant investment from Castrol and The Race Group. There are three levels of co-branding available – basic, bespoke and complete dual branding – to help the garage build its reputation for offering a high-quality, professional service and help them stand out from the competition.

Commitment to quality
Jim Nicholls, Retail Operations Manager of Eden Tyres & Servicing explained: “In such a competitive market, and with so much new technology and changes within the automotive industry itself, you really need to be on top of your game in terms of technical knowledge and service. Having built up a reputation across the Midlands for embracing innovation and the latest automotive technology, it’s important to us that we maintain those high standards. We’ve been a customer of The Race Group for many years and when they told us about the Castrol Service network we knew it would be a winner for us.

“Our association with the Castrol name allows us to naturally attract customers that understand and appreciate the importance of using high quality products. Having the Castrol signage within our workshops really helps when we’re opening new sites in areas where we might not have much brand recognition ourselves.”

As a Castrol Service site, the team of technicians across all Eden Tyres & Servicing sites are able to take advantage of an extensive online training service. Access to this resource allows them to understand the ins and outs of all the products that they are being offered, their benefits and how to deal with potential objections from customers opting for more premium products.

Trusted
With Castrol branded signage, POS displays and workshop clothing staff uniforms, Castrol Service sites are able to capitalise on Castrol’s strong brand awareness amongst consumers to build a trusting relationship with their customers. According to Castrol Service, the endorsement of such a well-known brand means member garages can more effectively communicate the benefits of choosing them to look after their customers’ vehicles.

The Castrol Service Plus network in the UK is driven by The Race Group, a strategic lubricants partner for Castrol. To find out more about The Race Group, part of Certas Energy, visit www.theracegroup.co.uk





Annual Exams are COMPULSORY… SO IS ANNUAL TRAINING

Barry takes a close look at Annual Training and what the DVSA will be expecting to see as we move forward
Published:  05 November, 2018

As we all get used to the new annual exam and training process the DVSA will need to crank up their focus on our training.  The DVSA can easily enforce the annual exam, as we have seen in the 2017 – 18 year. The requirement to enter your results in order to continue testing is a pretty easy way to keep us all focused.


In the heat of the fault

Hannah Gordon changes hats this month, and tells us how she solved an interesting fault
Published:  02 November, 2018

At the workshop we cover all kinds of vehicles, old, new, big and small but with all these vehicles we need up to date diagnostic equipment to be able locate faults within the electrical system.
    
In the workshop this summer was a 2009 Volkswagen Golf that had an intermittent issue which meant the car would go into limp mode, the cruise control was disabled and the climate control wouldn’t work. Understandably in the weather we were having the lack of air conditioning was a major concern to the customer. No one wants to be without air conditioning in 30Cº.
    
I plugged in the trusty diagnostics reader and came up with four faults. These included turbo boost sensor, manifold pressure, throttle pedal position sensor and ‘fuel system
too rich’.
    
In my experience cars can throw up all kinds of trouble codes even when there is no issue with that part. I wouldn’t say some manufacturers are more troublesome than others but if a light does appear on the dash it’s best to get it checked out as soon as possible.

Issues
I cleared the fault codes and told the customer to see how it drove and if the issues resolved themselves. The customer had the car for just an hour before they called and said that the problem had reoccurred, as much as this is a pain for the customer I always clear the faults and see if it happens again rather than changing unnecessary sensors. I got the Golf back into the workshop and once again plugged the computer in, which brought up one code. This was the throttle position sensor. A quick call to VW and a discussion with their parts people showed that this particular issue can lead to the cruise and climate control not working.
    
Next day delivery on the part means the car came back in the following day. One bolt, two plastic clips and an electrical connection later and the pedal was off. Gone are the days of the throttle cable. The throttle response is now done by a sensor on the pedal which works out how far the pedal is being pushed and tells the engine how to respond. It is clever stuff,  when it works.
    
A pedal replacement on the Golf only takes five minutes and another clear of the fault code before taking the car for a road test. On the test drive cruise and climate control were checked as well as making sure no dash lights had appeared.
    
Modern mechanics have become very computerised. Dash lights appear whether it is indicating an issue with the airbag systems, ABS or engine and diagnostic computers are so important to narrow down what the issue could be. I dislike the reliance that some workshops put on just trusting what appears on the screen of the diagnostics. It is still imperative that mechanics test sensors and look into live data to make sure that unnecessary components are not replaced and the costs put onto the customer, who will have to pay.



Ignition primary good earth path

Let’s get it started...

Frank Massey looks at how to get to grips with ignition combustion diagnostics which is an increasingly complex subject
Published:  22 October, 2018

Let me begin with the simplest of all overviews: There are four possible causes of combustion failure or malfunction; and please note my refusal to use the word misfire. The word is meaningless without a definitive confirmed diagnosis. The four possible causes are:


Site Audit snippets: Miscellaneous Equipment

Barry from MOT Juice helps to prepare for the inevitable DVSA site visit
Published:  08 October, 2018

Every MOT bay is required to retain and maintain a bunch of mandatory miscellaneous equipment. First let’s get the words from The MOT Testing Guide 6th Edition:

5.6 Miscellaneous equipment


Hybrid tech in motor sport

Peter Coombes looks at what can be learned about EV/hybrid tech from its use in motorsport
Published:  01 October, 2018

If you have even a passing interest in motorsport, you are probably aware of, and have an opinion regarding the use of hybrid technology in Formula 1 racing. Back in 2009, the use of electric motors was allowed, which enabled the additional electric power to supplement the power produced by the conventional engine.
    
In effect, a Formula 1 car could operate in much the same way as most mass produced hybrid vehicles because electric motor could also function as a generator to charge batteries. During power-off driving (braking and deceleration) the kinetic energy of the moving car and rotating engine drove the generator, which charged the batteries; but the energy transferred from the moving car to drive the generator also helped to slow the vehicle. The stored or recovered electrical energy could then be fed from the battery back to the motor when additional power was required. This system was known as a ‘Kinetic Energy Recovery System’ or KERS; and for the purists who like the sound of a hard working petrol engine, this KERS hybrid technology was OK because the 2.4 litre V8 engine still did most of the work and sounded great.
    
After a bit of a bumpy ride, for 2014 the hybrid F1 hybrid regulations evolved into a more complex set of rules that specified more complex technologies. The energy recovery systems were allowed to deliver a maximum of 12KW (160hp) of power in addition to the power delivered by a 1.6 litre V6 turbo-charged engine; but for 2014 onwards, there were two types of energy recovery systems that had to be used. Both types of energy recovery systems still use a ‘Motor/Generator Unit,’ which unsurprisingly is known as an MGU; but one system is then known as MGU-K (Motor/Generator Unit Kinetic), and the second system is known as MGU-H (Motor/Generator Unit Heat).

MGU-K
The MGU-K system is much the same as the original KERS system used from 2009. The Motor/Generator Unit is usually connected by gears to the engine crankshaft, therefore when the unit functions as a motor and draws electrical energy form the battery, the motor feeds mechanical energy back to the crankshaft to provide additional power and torque (such as for acceleration). During power-off driving, the engine is still connected to the driving wheels; therefore the Kinetic energy of the moving car again rotates the engine and the electric motor, which now functions as a generator to re-charge the battery.
    
The illustration (Fig 1) shows a basic layout for the MGU-K kinetic energy recovery system, but note that for convenience, the motor generator is shown connected directly to the front of the crankshaft but it can be located on one side of the engine beneath the exhaust manifold. The illustration also shows a battery management/electric power controller that regulates the power delivery of the motor and controls the re-charging process when the motor functions as a generator.
    
A lithium-Ion battery pack is usually used to store the electrical energy, although super-capacitors have apparently been experimented with that can accept a re-charge and then discharge electrical energy more quickly than a battery.
However, with the second energy recovery system, the Motor/Generator is driven by the rotation of the engine’s turbocharger , which is driven by the flow of hot exhaust gas (which contains Heat Energy). Therefore the two systems are referred to as MGU-K (for kinetic) and MGU-H (for heat).

MGU-H
The second energy recovery system (MGU-H) also makes use of a Motor/Generator Unit; but instead of being connected to the engine crankshaft, this unit is connected to the engine turbocharger (Fig. 2). As with road vehicle turbocharging, hot exhaust gas from the internal combustion engine drives a turbine that is connected to a compressor that then draws in air and forces it into the engine intake under pressure. But because the engine only produces high volumes of hot exhaust when the engine is under load and the throttle is open sufficiently to allow a higher mass of air to enter the engine, the turbocharger is only effective under higher load driving conditions.
    
With the F1 engines, the turbocharger (which can rotate at speeds in the region of 100,000 RPM or more) is then also connected to the MGU-H Motor/Generator Unit, so as well as forcing air into the engine, the turbocharger also drives the MGU-H and generates additional electrical energy to charge the battery.
    
The clever bit however is the use of the MGU-H to then drive the turbocharger. When the throttle of a turbocharged engine is initially opened to obtain more power (especially after decelerating when the engine might be at low RPM), the turbocharger speed will have reduced to low or almost zero RPM. It therefore takes a brief period for the turbo charger to spin up, but this is then also dependent on the engine responding to the open throttle and then creating higher volumes of exhaust gas to drive the turbocharger. Therefore there is a time lag between opening the throttle and when the turbocharger can actually increase the airflow into the engine to produce increased power and torque; and this inevitably has an effect on how quickly the vehicle accelerates. Because the MGU-H motor/generator is also connected to the turbocharger assembly, it can actually spin-up the turbocharger immediately when additional power is required (which will be before the exhaust gas is able to drive the turbocharger). In effect, the turbocharger also becomes an electrically driven supercharger.

Controlling electrical power and electrical generation
The operation of MGU-H Motor/Generator Unit is again controlled by the battery management/electric power controller, which therefore controls when the MGU-H functions as a turbocharger drive motor and when it functions as a generator. The control unit therefore has a complex task of regulating both the MGU-K and MGU-H motor/generator units so that the additional power provided by the electric motors is within the specified limits imposed by the regulations, and that the additional power is only available for the specified periods during a lap of the circuit.
    
The electronic control system then has one other important control function, which relates to braking. During deceleration and braking, when the MGU-K system is recovering kinetic energy from the moving car to drive the generator, it creates a significant braking effect on the rear wheels. If the driver is also applying the normal brakes at the same time, there will a combined braking force from the brakes and from the MGU-K. Any increase or decrease in the braking force provided by the MGU-K could then alter the total amount of braking force applied to the rear wheels, which could either lead to brake lock up or to a lack of rear braking. The electronic control system for the MGU-K must therefore communicate and influence operation of the braking system, to ensure that the driver remains in overall control of the braking forces.
    
Although the use of hybrid technology in F1 does accelerate the technology learning curve (pardon the pun), one big disadvantage is that use of the turbocharger muffles the exhaust noise, which does tend to upset the purist petrolheads.
   


Non-intrusive testing

Want to get stuck into a diagnostic investigation without sticking anything in? Karl Weaver shows you how...
Published:  21 September, 2018

As technicians we’re all expected to be able to diagnose a fault within a sensible timescale, for a reasonable price, then guarantee the fix. With correct training, information and tools this is possible. However, we are often faced with multiple faults where cause and effect may not always be straightforward. We can be in a situation where we need to rectify faults before we can move on to the next. Also, if the repair cost could outweigh the vehicle’s value or customer budget then great care must be taken explaining the situation, agreeing a starting fee and preparing and executing a successful diagnostic plan.

Recently we were presented with a BMW X3 for poor performance and a suspected DPF fault. After interrogating the customer we gathered all necessary information. Initial diagnosis confirmed multiple fault codes and a blocked DPF. Determining what caused the DPF to block is vital for the correct diagnosis and preventing reoccurrence. We created a test plan to test each fault and separated them into faults that affect the performance, faults that can cause the DPF to block or prevent regeneration and ones that don’t. In order to fully test the vehicle we would need to clean the DPF first as the exhaust back pressure was so high, the vehicle was barely drivable. As a member of the DPF Doctor network we have a very successful method of cleaning the soot from the DPF without the need for removal and access to many manufacturer-specific tips with DPF faults. The information and knowledge within the DPF Doctor network has proved to be invaluable and has given us an outstanding success rate. With our test plan ready we were able to calculate a sensible labour figure to conduct the tests required. The customer authorised the labour and the DPF clean.

Several faults were straightforward. A multimeter gave us conclusive results and made it easy to quote for replacement parts and labour time to fit them. The main fault causing poor performance required a little more thought to keep diagnosis time to a minimum. A low boost pressure fault code doesn’t tell us why the pressure is low. Driving the vehicle whilst monitoring the boost pressure showed the fault was intermittent, so an external boost leak was unlikely. A smoke test was also carried out which revealed no leaks. In this instance, the EGR valve could be a likely culprit. This engine uses a vacuum controlled EGR valve with a position sensor built into the diaphragm. As tempting as it was to unbolt it and take a look, this would all take more time then factor in the risk of rusted bolts etc. With a position sensor one would think if the valve was to stick then a fault code would be set. We had to plan a simple, conclusive, yet non-intrusive way of testing the EGR system quickly.

The conventional vacuum controlled EGR system consists of the EGR valve which includes the diaphragm with a 5 Volt position sensor and the vacuum control solenoid valve which uses vacuum from the brake servo vacuum pump and is controlled by the ECU on a duty cycle. The position sensor will typically show 0.5 to 1.2 Volts when fully closed and 3.9 to 4.5 Volts when fully open. One side of the solenoid valve has a 12 Volt (battery Voltage) supply and the ECU switches the ground path on and off at varying duties to vary the vacuum amount thus varying the EGR valve position. The ECU looks at the position of the valve and adjusts the duty to achieve the position desired similar to how an ECU uses the oxygen sensor to adjust the air/fuel ratio. With the following tests we were able to check every component in the system.

Test one
We connected the Mityvac directly to the EGR valve and the oscilloscope connected between the signal wire and battery ground. As we had already smoke tested the entire inlet system we connected the smoke machine directly to the inlet manifold in place of the intercooler hose. With the smoke machine running and the ignition on (engine off) we used the Mityvac to fully the valve to check it had no vacuum leaks (split diaphragm), then we opened and closed the valve slowly and then quickly. This confirmed the following:


Inject some knowledge

Frank Massey examines the changing role of fuel injectors, and the problems you can come up against when dealing with these components
Published:  17 September, 2018

At the heart of fuel delivery is the injector. If there is a single focus point that has helped reduce emissions and boost performance it’s the injector. Despite this, we don’t pay it enough attention, and I include myself in this critique. Let me qualify this by asking a rhetorical question; How many of you have injector bench test capability?

I do, but freely admit to not giving it a more prominent position in fault diagnosis. I am going to expand later just how intrusive testing should be conducted. To begin, a short trip down memory lane won’t do any harm in understanding basic problems.
    
Injector problems started in earnest when lead was removed from gasoline. The Nissan 1.8 turbo and Austin Montego 2.0efi were two of the most problematic examples. Both used 15ohm single event saturated triggering with approximately 1-amp peak current. This was back in the days when we were not measuring current nor did we have an injector bench.
All the diagnostic evidence came from the 4-gas analyser. CO and O2 should balance at approximately  0.5%, as this will achieve a near perfect lambda 1 ratio, 50-100, CO2 at its highest at around 17-18%.
    
A lot has happened since then. The key to ideal fuelling is in reducing the lag or dead time in injector response to PCM control. As engine power increased and turbos became almost mandatory, more fuel was required. To achieve these aims, opening times were increased to a point where they were in danger of colliding at high engine RPM. We are still talking port injection here, fuel pressures crept up to four-bar and high flow injectors started to be introduced.

Current ramping also changed to peak and hold with peak values of around 4-amps. For the time being things stabilised, with little or no obvious common injector problems. The next challenge manufacturers faced was to reduce the internal mass of the injector components. In plain English they got smaller, lighter, less robust, and with lead free legislation less reliable. Remember Fiat iaw injectors?

Precise control
As EU emission rules became more stringent, the need for even more precise control was inevitable, and along came direct high-pressure injection. Lets explore the variables of fuel transportation, variable delivery pressure 50-200bar, multiple injector strikes and adjustable delivery timing. Peak current now reached 10-amps and pwm switching became commonplace.
We now have gasoline injection that more  closely resembles diesel injection protocols. They also bring similar problems. Fuel is no longer delivered through the inlet port, leading to a build up of carbon behind the valves. This effect, the critical swirl in the cylinder, is essential for complete combustion. Filtration and fuel quality are now major considerations for reliability.

Hostile environments and anomolies
Injectors are now mounted in a more hostile environment, more pressure, more heat, more tip carbon. So, the need for testing and cleaning has come full circle from the lead-free era. A major problem here is the stress caused to the injector body by techs not using the correct removal tool.

Remember the comments on lighter internal mass; This means than bending stresses during removal leads to intermittent combustion anomalies. I do love that word, it more accurately describes incomplete combustion, often without any credible serial fault data.

New fault phenomena
Now let’s notch it up a bit and introduce some new fault phenomena. The internals are so light they can suffer mechanical failure, and the closure spring can break. The internal filter basket has been moved to a more central position, resulting in inaccessibility for replacement.


It CAN be done!

Barnaby Donohew has to stick to his guns to track down the ‘simplest’ of faults
Published:  10 September, 2018

We all remember certain jobs which test our nerve but ultimately serve to strengthen our capabilities. Proper learning experiences so to speak. Unsurprisingly, these memorable jobs tend to occur when tackling novel technologies or environments which, by their nature, can be unsettling.
    
Some time ago a customer arrived with a MINI having persistent warning lights, instrumentation faults and bearing a new instrument cluster and engine control unit. Mindful that the expensive repair history must have included some seriously ‘in-depth’ diagnosis, I decided to get involved and see what I could do to fix the issues.

Ruling out
A system scan reported various powertrain CAN faults in the engine, ABS and instrument cluster control units, indicating a system-wide communication issue but with no systematic patterns to help isolate the fault. The MINI had a separate diagnostic bus, which thankfully permitted scan tool communication in the presence of a CAN fault. However, CAN access was not available on the diagnostic connector to aid recording of the signals. Instead, an oscilloscope was connected to the engine control unit (Figure 1) to reveal that the wires were unlikely to have shorted together, to Earth, nor to +5V, as the signals from the engine control unit were almost ideal. The fault was more likely due to circuit integrity. After powering down the CAN this was confirmed, as a 120 Ohm resistance was measured between the high and low lines (around 60 Ohms was expected).
    
Subsequently, the customer was called with an update and to authorise further expenditure. The next stage involved pulling the car apart to fully check the wiring and control modules. Plainly, it was unwelcome news.

Added pressures
When conscious that the meter is running, doubt can creep in and you find yourself asking if a wiring fault is too simple, alongside other related questions. This was not a good time for misinformation. The resources available (course notes and workshop information) identified the MINI’s engine control and ABS units as each having a 120 Ohm terminating resistor between the CAN pins. Subsequent measurements determined a resistance of 120 Ohms on the engine control unit but many kilohms on the ABS control unit. Was it faulty? Nerves started to fray. Following a thought process akin to James Dillon's mantra "what would you test next if the part you had just fitted did not cure the fault," basic procedures were recalled.
    
Firstly, on this MINI the terminating resistors actually were in the engine and instrument control modules (all were fine). Next, a series of continuity tests isolated an open circuit on the CAN-H line between the ABS and engine control units. It was located in a well-protected and tiny portion of wire, equidistant between the terminating connectors. Figure 2 shows the damage.
    
The process demonstrated to me how, during stressful situations, it is worth trying to adhere to basic procedures as faults are often straightforward. As it turns out, this would have been good advice for the recent Top Technician practical tasks, which proved a very similar experience – I wish I had listened! For anyone thinking of entering, I highly recommend it.


Cut to the chase

Damien Coleman from Snap-on discusses how preparation can lead to easier diagnostics
Published:  28 August, 2018

Many modern systems, such as common rail diesel injection, can appear to be so complex that they seem to operate by magic. Over time, such systems are only going to become more and more complex, so understanding them means you can gain a head start on their repair.
    
You can be presented with a seemingly endless amount of data relating to fuel pressure feedback, fuel pressure control, cam/crank synchronisation, measured mass airflow, injector flow correction feedback, and many other areas.
    
However, if you prepare yourself with a fundamental understanding of the system and all data available pertaining to the fault, a systematic approach to the fault-finding procedure can be carried out.  
Data overload

Figure 1 shows  the live data returned from a common rail diesel injection vehicle with an EDC16 engine management system.
    
There is an enormous amount of data available from these data parameters, which can allow you to ascertain the nature of the fault. The actual operation of the fuel system can be compared to the desired system operation and using the data, a decision can be made on the condition of the system and where a fault (if any) may be.
    
An oscilloscope is another important tool when investigating a fault with such a complex system. Figure 2 shows an oscilloscope waveform from an Audi with the 2.0L common rail engine. The yellow trace is the fuel rail pressure sensor voltage (feedback) and the green trace is the current flow through the inlet metering valve (command). The waveform was captured during a wide open throttle (WOT) condition.
    
This image alone tells us that the fuel inlet metering valve is a normally open valve. The engine control module (ECM) decreases the duty cycle when the required fuel pressure is increased. This allows less current to flow through the solenoid and the valve is allowed to open, which increases the fuel pressure measured at the fuel rail.

Full analysis
When the fuel pressure demand decreases, the duty cycle control from the ECM increases. This allows more current to flow through the solenoid which results in a reduction of the fuel pressure. Duty cycle is often referred to as pulse width modulation (PWM) control.

The duty cycle control on the ground side of the fuel inlet metering valve can be analysed using an oscilloscope, as seen in Figure 3. The waveform below displays the fuel rail pressure feedback voltage (yellow trace) and the fuel inlet metering valve duty cycle control from the ECM (green trace).
    
The oscilloscope is connected to the control wire for the fuel inlet metering valve. The technician must be mindful that this is the ground control circuit. System voltage on this wire indicates open circuit voltage. The diagram in Figure 4 shows the best method of connecting this set-up.
    
By careful analysis using serial (scan-tool) and parallel (oscilloscope) diagnostics you will now be in a position to identify the area of concern accurately and in a timely manner. Knowledge, together with the right equipment and experience therefore benefits technicians by leading to a reduced diagnostic time and an easier fault finding method, rendering these complex systems much less so.


Issues of rotation

Andy Gravel takes on a tricky wheel-speed sensor issue
Published:  16 August, 2018

I received a phone call from another garage: 'We've seen you in the Top Technician magazine and are wondering if you would be interested in looking at an ABS fault for us?' The call went along the usual lines, can the symptoms be recreated? What is the repair history? The vehicle was booked in for me to take a look.

The car in question was a 2011 Honda
CR-V, which had been taken as a trade in at a local garage, the fault only occurred after around 50-70 miles of driving, at which point the dash lights up with various warning lights. The vehicle had been prepped and sold to its new owner unaware a fault was present.

Fault-finding
After only a few days the fault occurred and the vehicle returned to the garage. They had scan checked the vehicle and the fault code ‘14-1- Left Front Wheel Speed Sensor Failure’ was retrieved. On their visual inspection, it was obvious a new ABS sensor had already been fitted to the N/S/F and clearly not fixed the fault. Was this the reason the vehicle had been traded in? They fitted another ABS sensor to the N/S/F and an extended road test was carried out. The fault reoccurred. This is when I received the phone call; the garage was now suspecting a control unit fault.
    
My first job was to carry out a visual inspection for anything that was obviously wrong and had possibly been over looked: correct tyre sizes, tyre pressures, tyre tread and excessive wheel bearing play. All appeared ok. The ABS sensors fitted to this vehicle are termed 'Active' meaning they have integrated electronic and are supplied with a voltage from the ABS control unit to operate. The pulse wheel is integrated into the wheel bearing, which on this vehicle makes it not possible to carry out a visual inspection without stripping the hub.

Endurance testing
With the vehicle scan checked, all codes recorded and cleared, it was time for the road test. Viewing the live data from all the sensors, they were showing the correct wheel speed readings with no error visible on the N/S/F. The road test was always going to be a long one, fortunately at around 30 miles, the dash lit up with the ABS light and lights for other associated systems; the fault had occurred. On returning to the workshop, the vehicle was rescanned, fault code '14-4 - Left Front Wheel Speed Sensor Failure’ was again present. Again using the live data the sensor was still showing the wheel speed the same as the other three, so whatever was causing the fault was either occurring intermittently or there was not enough detail in the scan tool live data graph display to see the fault. It was time to test the wiring and the sensor output signal for any clues.
    
Using the oscilloscope, the voltage supply and the ground wire were tested and were good at the time of test. I connected the test lead to the power supply wire and using the AC voltage set to 1V revealed the sensors square wave signal. Then rotating the wheel by hand and comparing the sensors output to one of the other ABS Sensors, again all appeared to be fine. A closer look at the signal was required, zooming in on the signal capture to reveal more detail; it became easier to see something was not quite right with the signal generated by the sensor when the wheel was rotated. With the voltage of the signal remaining constant, a good earth wire and the wheel rotated at a constant speed the signal width became smaller, effectively reporting a faster speed at that instant, not consistent with the actual rotational speed of the wheel. It was difficult to see the error, zooming out of the capture to show more time across the screen it could be seen that this appeared in the signal at regular intervals, although not visible all the time because it was such a slight difference. Using the cursors to measure between the irregular output and counting the oscillations, it was clear that it occurred at exactly the same interval every time. It had to be a physical fault on the pulse wheel.
    
This meant a new wheel bearing was required. The vehicle was returned to the garage as they wanted to complete the repair, a new wheel bearing was fitted and extended road testing confirmed the vehicle was now fixed.


Under no pressure

Top Technician 2015 winner Andy Gravel finds a DPF regeneration to be more than it seems
Published:  06 August, 2018

Once the news started to spread about my Top Technician win, the phone started to ring with more interesting and challenging jobs, usually ones that have been doing the rounds between other garages without success.
  
 A phone call came from a local parts supplier, a visiting rep was having issues with a DPF. They believed it needed a simple regeneration to get it back on the road and asked if I would be able to do the job. After checking the Blue Print G-Scan, the function for a forced regeneration was available, I believed I would be able to carry it out and booked the job in.

Basic beginnings
After traveling from two hours away, the vehicle arrived. The customer was questioned, ‘Why do you require a DPF regen?’ Being a parts rep within the motor trade, her garage visits were frequent; various attempts had been made to resolve the issue. With conflicting advice being given and quotes between £600 - £1200 to fix the vehicle, the customer was obviously confused and unsure about what to do.
    
The engine management light was on, so the obvious place to start was a scan check for fault codes. The vehicle showed P2002: Particulate Trap Below Threshold.
    
Viewing the live data for the DPF pressure sensor, key on engine off, displayed a 0kpa pressure reading, a good start for a sensor plausibility check. With the engine running and RPM increased, the sensor reported a suspiciously low-pressure reading, not one I would associate with a saturated DPF. I decided to use the Pico Scope to look at the DPF pressure sensor voltage in real time. After confirming the power and ground circuits to be ok at the three wire pressure sensor, the signal wire was checked. Again key on engine off, 750mv was displayed, a sensor plausibility check and again this was good. Starting the vehicle and increasing the revs revealed exactly the opposite to what I had expected, a negative voltage reading. The voltage should increase as the exhaust pressure increases.

What’s wrong?
One area I wanted to check was that the pipes were not connected the wrong way around. I decided to use the Mity Vac to apply pressure to the sensor pipe connected in front of the filter. This showed a positive rise in voltage, further proving good sensor functionality and confirming the pipes to be correctly connected. Connecting the Mity Vac to the pipe after the filter and applying pressure, simulated the negative voltage which was seen when the vehicle RPM was increased, simulating the fault. The sensor pipe in front of the filter must be blocked.
    
I located the steel pipe that is fitted in the exhaust in front of the filter to reveal soot marks, it had been leaking exhaust gasses. On a closer look it was unscrewed from the exhaust while still located in the hole due to the pipe bracket allowing the slight leak of exhaust gasses. Once the pipe was removed it was clear to see the soot had built up and blocked the small hole in the end of the pipe. I unblocked the pipe, checked to make sure the mounting hole on the exhaust was clear and refitted it.
    
Using the Pico Scope again on the signal wire, it now showed a positive rise in voltage when the RPM was increased. The live data now showed a small pressure increase, the filter was not blocked. With all fault codes cleared, an extended road test was carried out, the pressure reading stayed low throughout and no fault codes reoccurred confirming the fix, the vehicle did not require DPF regeneration.

With no parts required to fix the vehicle the repair cost was far lower than the customer expected due to the previous attempts. The vehicle was returned to the customer who was surprised by the
outcome of the repair and relieved by the associated costs.



TT Archives:  Top Technician issue nine 2016 | www.toptechnician.co.uk


Highs and Lows

Karl shares his insights on the conundrum of EGR. A riddle, wrapped inside an enigma, recirculating exhaust gas through the system
Published:  30 July, 2018

When faced with diagnosing a fault, in order for us to be able to test the system it is crucial we understand the system’s layout, components and function. We recently faced a fault in a system we had little experience on, so it was an ideal opportunity for a bit of studying.

Technical information is readily available from many sources, be it manufacturer or generic information, and does not take too long to find. While Google isn’t really a substitute for diagnostics, in situations like this it can be very useful for generic information. The fault on this vehicle turned out to be something so trivial I won’t bore you with it. What I would like to share is the valuable information I picked up along the way.

Main purpose
Exhaust gas recirculation (EGR) is nothing new, it’s been used on petrol and diesel engines for many years and while layout and control has varied in design the principle has remained the same. It is important to understand that manufacturers use different methods and configureuration, and for this article I’ve studied several and have tried to demonstrate a generic system.

The main purpose of EGR is to reduce the level of harmful Nitrogen Oxide (NOx) gases emitted from the vehicle’s exhaust. NOx is present in exhaust emissions due to high combustion temperatures and pressures. Under light load/cruising conditions the EGR system directs a proportion of the exhaust gas back into the engine’s air intake. This reduces the oxygen levels which in turn reduces combustion temperature resulting in a lower NOx emission. When power is required from the engine the EGR system closes to insure a more efficient combustion (see figure 1).

EGR on/off
This is the conventional system in its closed (off) position.  During operation exhaust gases are taken from the exhaust manifold (pre-turbo), passed through a cooler (10) up to the EGR Valve (6). The cooler is a heat exchanger that not only uses the engine coolant to cool the gases to increase the mass but utilises the heat to warm up the coolant faster which helps the interior heater warm-up faster. The EGR Valve (6) can be either electrical of vacuum operated. The  powertrain control module (PCM) commands the EGR valve to open by a specified amount dependent on engine conditions (see figure 2).

Some EGR valves have a position sensor that provides feedback to the PCM to ensure the correct position has been achieved. In a system where the EGR valve is not equipped with a position sensor, the PCM monitors the Mass Airflow signal in order to regulate EGR flow. This is achievable due to the fact that as the EGR valve is commanded open and gases start to flow, the air flowing in to the Mass Airflow Sensor will decrease. The calculation is made using tables of data (mapping) within the PCM’s software. Understanding this is crucial when diagnosing running faults as a fault in the Mass Airflow can easily affect the EGR system and vice versa.

Understanding and diagnosing airflow and EGR faults I find can be easier if you look at it pressure differential. If air is flowing through a tube with a restriction in it, the air pressure after the restriction will always be lower than the pressure before the restriction. The difference in pressure will vary depending on the mass or pressure of the air and the size of the restriction.

Air intake/throttle flap
The air intake/throttle flap (see figure 3) generally defaults to the fully open position while the EGR valve defaults to the closed position. The purpose of the flap is to reduce the pressure on the engine side. As the intake flap starts to restrict the airflow, the pressure decreases to a pressure lower than that of the EGR pressure and the EGR gases start to flow into the engine’s air intake. If the exhaust gas pressure was slightly lower than the air pressure entering the engine then the gases would flow in the wrong direction.
    When in good working order this system serves its purpose. However, due to the fact that there is particulate matter in the exhaust gases, the system and components will slowly become blocked, causing reduced flow and valves starting to jam or not seal correctly. The air intake system often contains oil residue from the engines breathing system and slight oil loss from the turbo itself. When this oil is mixed with the particulates in the EGR gases it makes a very sticky gunk that starts to block the inlet manifold and intake ports.

When the engine is under load and turbo boost pressure is required, the EGR valve needs to close and seal. If an EGR valve isn’t sealing correctly when closed then boost pressure will be lost into the exhaust system. The lower boost pressure and reduced oxygen level affects the combustion which in turn causes more particulate matter which only adds to the issue. If the EGR valve is stuck wide open then in most cases the engine will barely run.

High pressure system    
Euro 6 was introduced in September 2014 which demanded much tighter emissions than previous which required an advance in emission control technology. While the precise control of the fuel side of the engine management system has gained precision with higher fuel pressure and multiple injections within the cycle, the air intake, exhaust and emission control systems have too. Most manufactures use a high and a low pressure EGR system.  Prior to this most EGR systems were relatively simple and fell under the ‘High Pressure EGR’ title (see figure 4 and figure 5).

The high pressure system is similar in layout to previous systems but serves a slightly different purpose. The system is only used during the warm-up phase of the engine from cold start. There is a pre-turbo passage from the manifold directly to the high pressure EGR valve (6). As the system is only used in the warm-up phase there is no need for a cooler. In this particular system there is a distribution channel that directs the gases equally into each inlet port. The purpose of this system is to raise the intake air temperature in order to improve combustion and reduce the warm-up time for the catalytic convertor/NOx storage catalyst (7) allowing them to function sooner. Once at operating temperature the system is pretty much redundant.

Low pressure system
The low pressure system (is active under most engine operating conditions and its purpose replaces that of the older systems- to reduce NOx gases (see figure 6). A proportion of the exhaust gas is collected after the Diesel Particulate Filter (8) and passes through a Wire Mesh Filter (9), through the EGR Cooler (10), up to the Low Pressure EGR Valve (11). The EGR valve then controls the flow through a channel up to the intake side of the turbocharger. The wire mesh filter ensures there is no particulate matter entering the system and also in the event of the particulate filter substrate breaking up, it also protects the rest of the system including the turbocharger, air intake and engine internals from damage. The cooler reduces the gas temperature which in turn increases the mass allowing a higher volume of exhaust gas to be recirculated. Due to the exhaust pressure after the particulate filter being quite low and also the air intake pressure before the turbo charger also being low there is and Exhaust Flap (12) fitted. By closing this slightly the exhaust pressure increases which causes the gases to flow back towards the turbocharger.

Key benefits
These systems usually have between three and four  exhaust gas temperature sensors each placed at key points of the exhaust system and two pressure differential sensors. The first is measuring pressure before and after the particulate filter (to calculate soot loading) and second between the DPF outlet and the point after the EGR valve, before the turbo. Coupling these six signals with the Mass Airflow sensor, the positions of both EGR valves and the intake flap, the turbo variable-vane position and the intake pressure (MAP), using the mapping within the PCM’s software means it can also make all calculations necessary. This provides an extremely high intake pressure and exhaust after treatment control.

The key benefits of this system are that the exhaust gases are free of any particulate matter which keeps the entire system much cleaner and therefore reliable. The gases are also cooler meaning a greater mass can be used in a more effective way. Finally the gases re-enter the system before the turbocharger, allowing for the increase in boost pressures at lower engine load and RPM.

Does this make diagnosis harder than before? Not if you take the time to study the purpose of each component and how it works. I’ll openly admit it wasn’t that long ago that I would have taken one look at this system and sent it on its way! Nobody likes being beaten by a job but neither should we have to waste too many hours trying to guess what’s wrong with it, worse still start throwing parts at it. It took me half an hour to locate this info, an hour studying it and a further hour planning what tests I was going to conduct and what results I was expecting to see. What was wrong with it in the end? A faulty sensor confirmed with no more than a voltmeter! After replacing the sensor I wanted to confirm the repair and monitor the function of the components using serial data. Something I highly recommend doing is picking five lines of serial data on every car you work on that requires an extended road test and monitoring them to see how they behave and what effect driving style (engine load) has on them. I guarantee after 10 cars you’ll know what to expect and be far more confident in diagnosing related faults. It works for me!


Quality street

Ian Gillgrass looks at how the recent MOT changes mean a Quality Management System is essential
Published:  25 July, 2018

The MOT has gone through change over the past few years. There have been changes in the way the MOT tester and the MOT Centre Manager become eligible to operate a Vehicle Testing Station (VTS) through the qualifications that are available through various national and local training organisations,  through to the MOT tester having to manage their own Annual Training and the Annual Assessment.

In combination with the revised MOT Inspection Manual (aligning to the European Directive) being implemented during May 2018, some confusion may exist in this ever changing sector.

The VTS has several people roles that exist, one major role; the Authorised Examiner (AE) or Authorised Examiner Designated Manager (AEDM) being the person having the ultimate responsibility within the business.

A new VTS and those  changing their approved status will need an AE/AEDM to hold the Level 3 Award in MOT Test Centre Management prior to the VTS becoming approved by DVSA. Most training providers will deliver the MOT Centre Manager qualification. Part of the qualification is that the person understands how to operate a Quality Management System (QMS) for the purposes of the VTS. This has been identified as an area that most people struggle with within the qualification.

To implement an effective QMS program, the business must initially internally agree the standards that they set. The results are then collected and reported into the QMS. Any problem should have a corrective action. This should be written with an indication the people responsible to carry out the action along with a completion date. If the same problem repeats, then a plan should be developed to improve the situation, and put into action.

The following highlights a few areas that where the QMS needs to focus.

Training
The AE should ensure all staff (employees and contractors) fully understand their responsibilities. This enables them to carry out their job accurately and remain compliant with the necessary requirements.

The MOT tester should ensure that they meet the requirements of the MOT tester Annual Training and Annual Assessment. This year the annual training includes updating their knowledge of the MOT Inspection Manual which was introduced in May 2018. Most MOT testers will be familiar with the revisions and updates to the MOT Inspection Manual, either through specific training prior to the changes or reviewing the Inspection Manual during its implementation stages.

The AE should also ensure that the MOT testers that carry out tests at the VTS, are compliant with the requirements. Failure to do so will result in the MOT tester unable to test vehicles. It should be noted that some MOT testers that have not met the requirements have taken many weeks to become reinstated as an MOT tester as a result of non compliance which could reduce business income.

At present there is no requirement for the MOT Centre Manager to comply with the updating of their MOT knowledge but this could change in the near future.

Procedures
The AE should ensure that everyone involved in the MOT testing process within their business has access to key information, especially focusing on MOT test logs and MOT Test Quality Information (TQI).

TQI can be accessed by both the AE and also the MOT tester, reviewing the MOT test data applicable to their role. The data can indicate both strengths and weaknesses with the MOT testers and the VTS, it is therefore important that this data is regularly reviewed to identify any anomalies within the data and implement an ‘action plan’ to correct any deficiencies, therefore both the MOT tester and the AE have a responsibility in this area.

MOT TQI was highlighted as a requirement for the MOT tester annual training/annual assessment. It is therefore suggested that the MOT Centre Manager also updates their knowledge on Test Quality Information (TQI) and also MOT test logs.

The AE should ensure that the relevant people know procedures for the reporting of equipment defects/problems, the equipment maintenance and any equipment calibration requirements within the specified dates as indicated by the MOT Testing Guide. The AE must ensure that any appropriate records (calibration certificates) are kept and the records are held securely.
The AE should always ensure that the equipment is maintained and calibrated correctly, if a problem is detected (yes things do go wrong) preferable before a breakdown occurs then a clear process should be identified and the rectification of the equipment recorded.

Assurance
The MOT tests which are carried out at the VTS must always have the correct result, the security of data, information and passwords are maintained which will lead to the reduction in risk of MOT fraudulent activity. The protection of data used in the MOT process needs to comply with the General Data Protection Regulation (GDPR) which was also introduced in May 2018 replacing the Data Protect Action (DPA) that previously covered the data. The AE has a duty to ensure this has been complied with.
The process should also include a Quality Control process of the MOT tester to ensure that they produce satisfactory results, and to identify any future weaknesses in their MOT test procedures.

The MOT Testing Guide (updated earlier this year) indicates that a QC check needs to be performed on an MOT tester every two months. Best practice would indicate that the QC process is completed on each MOT tester more frequently such as every month. The QC check should be recorded and kept in-line with the requirements. The QC report should indicate the strengths and weaknesses of each individual (not just indicating the MOT tester is OK) with an ‘action plan’ (further training etc) on how to reduce the weaknesses. The next month Quality Control report should then indicate how the MOT tester has performed against the ‘action plan’. This could help to reduce the VTS risk score, improving MOT tester performance but also increase business performance.
Performing and recording quality control checks within an MOT business can be time consuming and often gets forgotten. The person carrying out the MOT QC must be carried out by an approved DVSA MOT tester. The QC can be achieved within the MOT testing team providing more than one MOT tester is engaged (one MOT Tester is nominated as the QC) or alternatively a service that an outside agency could provide. A Vehicle Testing Station with only one MOT tester could have a reciprocal arrangement with a nearby similar business by carrying out the QC check on each other.

Improvement
An effective QMS used within the VTS should identify any weaknesses that could put the station at risk. Once a weakness has been identified the business should develop an action plan to improve within the area of weakness. This will typically lead to an improvement.

All these points will help to achieve a low VTS risk score. The MOT centre manager should read and understand the various documents provided free by the DVSA on how to carry out a VTS risk assessment and to hopefully reduce the VTS risk score.
The AE can find out more on the qualification by contacting a recognised training provider delivering the MOT Centre Manager Qualification, this will help them better understand the requirements of a Vehicle Testing Station and the various MOT Testing documents and standards associated with MOT testing. Many of these requirements have been revised over the last few years, and it is a requirement for the AE to constantly update their knowledge to remain current. Remember the MOT Testing Guide was revised in early 2018 and many AEs do not have knowledge of the new requirements.


888... Lucky for some

Keeping a cool head, Frank Massey looks at how advances in some high performance engines will affect the how technicians approach the cooling system
Published:  17 July, 2018

With this month’s focus in Aftermarket on cooling, I thought a look at how technology has affected one of the oldest systems of the internal combustion engine. For illustration, I have chosen the Volkswagen Auto Group’s en888 engine, built in Mexico, Hungary and China hence the 888 insignia; It is their lucky number.

Its one of Audi’s high-performance variants. Its fitted in my Seat Cupra 2ltr, producing 400bhp with stock mechanicals. So, what are the benefits of advanced cooling systems? Heat derived from combustion, transferred by conduction and convection into cooling and the environment is in effect wasted energy. Controlling and where necessary containing it improves efficiency, not forgetting reductions in emission pollution.

Efforts
They have made stringent efforts in the mechanical design of the 888 to achieve savings in efficiency. Reducing engine weight, minimising internal friction, increasing power and torque, current with fuel economy initiatives.

The cylinder block wall is reduced from 3.5mm to 3.00mm. Internal friction is reduced with smaller main bearing journals, revised timing chain design, incorporating a dual pressure lubricating system. The balance shaft has roller bearings, piston cooling jets further improve thermal stability. The jets have PCM mapped control, while extra oil cooling is provided adjacent the filter housing, close to the activation solenoid and twin oil pressure sensors.

The engine can theoretically reach Lambda 1 from cold within 20-30 seconds.

Further technical innovations include reduced oil level, reduced tension force in the auxiliary chain mechanism, down shifting achieved with variable valve lift and twin scroll direct mount turbo design.

Advances
You will now appreciate that it is no longer possible to separate mechanical design, power delivery, emissions, and all-round efficiency, treating cooling as an afterthought.

Take the cylinder block design, which possibly has the biggest advances reserved within the cylinder head and coolant control module (water pump). The exhaust manifold is housed completely within the cylinder head casting. This ensures very effective conductance of heat. The emphasis is now on increase, maintain, reduce, thanks to an advanced dual valve PCM controlled coolant control module. The module is mounted at the rear of the engine block, belt-driven with a cooling fan to keep the belt cool.
By manipulating the two rotary valves, flow and temperature can be effectively controlled within very carefully controlled limits. The rotary valves are manipulated by a PWM 1000hz motor with SENT position feedback (single edge nibble transmission), a method used by the latest air mass meters.

Heat transfer into and from the turbo is much more efficient due partly to the direct mount and integrated cooling galleries surrounding the exhaust tracts.

The piston to wall clearance has been increased, with a special coating on the piston thrust side complimenting a direct gudgeon pin to rod contact, the DLC coating removes the need for a bearing bush.

The cylinder head porting incorporates ignition sequence separation, thus ensuring preceding exhaust pulses do not impede the energy from the current. This in combination with advanced turbine design further improves torque range and downshifting. Cooling control priority is applied to the occupants, then the transmission, further reducing frictional losses.

Complexity
Although not directly related to the cooling system, a dual injection system is fitted with its main function being emission reduction. Cold start is provided with three direct injection events, followed by port injection warm up. These systems do not run in tandem. Two thirds of the load range is controlled by port injection, with full load above 4,000 rpm delivered by induction stroke direct fuel delivery.

From a practical point of view, previous low-tech tasks like replacing coolant components and bleeding now requires electronic support through the serial interface. Using the correct antifreeze is now essential if premature corrosion is to be avoided. As a warning, capillary coolant invasion within wiring looms is well known in some French and GM vehicles, as some of you will be aware.
It is also worth mentioning that Volkswagen has modified the software controlling cooling in some of their diesel vehicles as part of the emission recall programme.

Predictably due to their complexity, I can foresee cooling systems being neglected during routine servicing , so expect to see faults as these systems age in the pre-owned market.



Well it was like that last year mate! And you passed it then…

Barry Babister from MOT Juice throws some light on warning lights
Published:  28 June, 2018

How many warning lights does it take to create an MOT fail? Put simply, just one - but how many choices do we have?  
    
Looking through the revised testing manual it’s hard pick out these faults amongst so many changes. Let’s see if we can summarise them for you as a refresher on what fails, some new and some old. Below is a list of
major failures:


Part Seven: Electric and hybrid vehicles

In part seven of his ongoing look into EVs and hybrids, Peter Coombes of Tech-Club considers the power electronics system
Published:  22 June, 2018

Over the past few months, we have looked at battery and electric motor technologies of electric and hybrid vehicles,
as well as looking at the advantages and disadvantages of batter power compared to fossil fuel power.  
    
Irrespective of whether a vehicle is powered solely by batteries and an electric motor or whether the vehicle is a hybrid that has the addition of a petrol engine for propulsion and
re-charging the batteries, the vehicle will require a sophisticated electronic system to manage and modify the electrical energy. In effect, the vehicles have an electrical management system that is often referred to as the ‘power electronics’.

Controlling electric motor speed and power
The obvious task of the power electronics system is to control the speed and power of the electric motor so that the vehicle can be driven at the required speed and achieve the required acceleration. As mentioned in a previous article, with Alternating Current (AC) motors the motor speed is regulated by altering the frequency of the 3-phases of alternating current. For light load cruise driving, the current flow provided by the battery pack to the electric motor might only be in the region of a 70 or 80 amps or less, but when the vehicle is being driven under high load conditions, the current requirement will be much higher. Therefore the power electronics can allow higher current flows to be delivered to the electric motor, with some reports quoting as high as 1,800 amps for brief periods on some Tesla vehicles during hard acceleration. However, the power electronics system will monitor currents and temperatures of the electronics, the batteries and the electric motor to ensure that overheating and damage do not occur. As an additional function, the power electronics systems will also control the cooling system (often a liquid cooling system) for the electronics, the batteries and the motor to help maintain acceptable temperatures.
    
Because most modern electric motors fitted to electric and hybrid vehicles are alternating current motors, the power electronics system must convert the direct current supplied by the battery into alternating current. The power electronics system therefore contains a DC to AC inverter.

Battery charging from a home charger or remote charging point
For pure electric vehicles the batteries are re-charged from home based chargers or remote charging points (and this is also true for many later generations of hybrid vehicles). The battery charging must be carefully controlled to prevent overheating and damage, therefore the power electronics system contains a charging control system to regulate the charging rate (voltage and current). Most charging devices provide alternating current, therefore an AC to DC converter forms part of the power electronics system to enable the batteries to receive direct current.
    
Note that for rapid charging (especially with lithium based batteries), the power electronics system can regulate the charging rate so that the batteries re-charge up to about 80% capacity relatively quickly (perhaps within 20 to 30 minutes with fast chargers), but to prevent overheating and damage, the charging rate is then significantly reduced for the remaining 20%
of charge.

Battery charging from an engine driven generator
Most mass produced hybrid vehicles use an internal combustion engine that can propel the vehicle, but the engine also drives a generator that can re-charge the main high voltage batteries. While the engine is running, the power electronics system again controls the charging rate; and again, the output from the generator passes through the AC to DC converter. Note that the power electronics system will be linked to or integrated with the engine management system, which will allow the power electronics to cause the engine to start and generate electricity if the batteries are low on stored electrical energy.
    
Because the electric motors fitted to electric and hybrid vehicles can usually function also as generators, when the vehicle is decelerating or braking (or coasting), the electric motor can therefore be used to help re-charge the batteries. The electrical output from the motor/generator will vary with speed; therefore the power electronics system must control the charging rate to the batteries. As with home/remote charging and charging with an engine driven generator, because the motor/generator produces an AC current, the generator output must pass through the AC to DC converter.

12-Volt battery charging
A 12-Volt electrical system is still used for electric vehicles, but because there is no engine driven alternator, the 12-volt battery is charged using power from the high voltage system. The power electronics system contains a DC to DC converter that converts the high voltage of the main battery pack down to the required voltage for the 12-volt battery. The charging rate for the 12-volt battery is also controlled by the power electronics system.

Additional functions of the power electronics system
As mentioned previously, modern electric vehicles (and hybrid vehicles) will be fitted with cooling systems to maintain the temperatures of the batteries, the electronics and the electric motor. Pure electric vehicles are more likely to be fitted with liquid cooling systems due to the higher currents required for the electric motor that is the only source of propulsion, whereas with hybrid vehicles that also use an internal combustion engine to propel the vehicle generally have less powerful electric motors and therefore often make use of air cooling. However, whichever system is used for cooling, the cooling system can be controlled by the power electronics system to regulate the amount of cooling being applied; note that with liquid cooling systems, the control can also apply to the electric cooling pumps that force the coolant to flow around the cooling system.
    
Another cooling or heating related function of the power electronics system is to ensure that the battery temperature is at the optimum temperature for charging (and for discharging when the battery is providing electrical power). Batteries charge much more efficiently and faster if they are at the optimum temperature of typically between 10 and 30ºC (or slightly higher for some lithium batteries); but the charging rate should be lowered for lower temperatures; and for many consumer type lithium based batteries, charging is not possible below 0ºC.
    
Because vehicles are equipped with a cooling/heating systems (for driver/passenger comfort as well as for controlling vehicle system temperatures), the power electronics system can switch on an electrical heater (that would form part of the cooling/heating system) when the batteries are being charged. Therefore, if the vehicle is being charged from a domestic based charger or remote charging station and the ambient temperature is low or below freezing, the battery cooling/heating system can raise the battery temperature to ensure charging take place at the fastest possible rate.



Tools to survive and thrive

John Batten takes a look at the art of diagnosis and the one tool to rule them all
Published:  11 June, 2018

My life as a business owner, trainer and technician is an interesting one. I was recently spending some time with a client after a course just shooting the breeze. You know the kind of thing, a cuppa, a cake and an hour just putting the world
to rights.
    
Part way through our conversation Matt proclaimed that I must be “living the dream!” This made me stop and think (something I’ve been told not to do by my wife) about how I am indeed very fortunate to have a career doing something I truly love.

Wading through treacle
Spending my days with like-minded business owners and technicians, helping them drive their careers and businesses forward. What’s not to like about that? Not much, but has my work life always been like skipping through meadow on a sunny day?
    
Quite frankly… No! Don’t get me wrong –  I’m a glass half full sort of chap and regardless of the task ahead I’ll give it my best and persevere until success emerges. However, on many occasions in my diagnostic career it was just like wading through treacle, and therein lies my point. To get to a place where you’re ‘living the dream’ you need wellies! Show me a successful technician and I’ll show you someone who’s great at wading. They’ve just waded long enough to build a versatile skill set along
the way.

The recipe for success
As with most things in life there are essential ingredients. With the right ingredients you’ll successfully avoid the diagnostic treacle swamp and swap this for a faster and more enjoyable repair experience.
    
“What’s this recipe?” I hear you cry. It has six elements that when bought together produce truly remarkable results. They are;


Expert training, Italian style

Frank Massey is overseas again, but while he is there, he takes a look at ways to predict common rail pressure faults
Published:  06 June, 2018

I have just returned from Modena, delivering a two-day advanced technical training seminar to 21 of Italy’s top independent technicians. I was travelling from across Italy and beyond, attending PCB Automotive’s international training programme, focusing on gasoline direct injection and common rail diesel.  

The essence of the training was the advanced application of Pico oscilloscope to diagnose and gain predictive evidence for a repair solution. The technicians were particularly interested in the techniques of high pressure pump testing pioneered by ADS several years ago.

Attending the event were diesel and gasoline specialist and Italy’s most respected Bosch trainer. No pressure then! The session began with an explanation of the importance of scope performance when gathering data at high resolution requirements. Acquisition, storage, display, test lead bandwidth and advanced triggering with math channel analysis.

As expected Bosch had a different political agender towards our pump proof testing. It was however received with enthusiasm and great interest once its accuracy and simplicity was experienced.

The session on ignition evaluation was of great interest especially when focusing on primary current ramping and slew rate. Further discussion on burn time and slope completed the morning session.

The four-course lunch was a typical treat of local Italian hospitality and cuisine. The afternoon session included the evaluation of load request with air mass and Lambda response. By comparing response and rise time evaluation it is possible to predict and confirm complex fuel delivery and combustion anomalies.

A full eight-hour day concluded with hybrid cart racing north of Bologna, followed by the inevitable pizza and Mr Moretti’s finest.

Data and interest
Day two and common rail diesel with a similar agenda,   with a strong focus on Math analysis of pressure and volume control against fuel delivery pressure. We have accumulated a vast database of rail pressure profiles, rise and decay times across all diesel manufacturers. This was of great interest to a Bosch pump and injector repair specialist. Approving nods and smiles throughout supported our confidence in this form of diagnostic analysis.

There was great interest in the examination and influence of rail pressure and air mass response time.  Converting digital air mass into a current profile enabled delegates to understand the speed and simplicity with which a technician can determine the source of an error, either hydraulic or sensor input.
The day concluded with certificates and a photo session. Teachers usually get apples from students so imagine my joy with a bottle of wine and finest olive oil.

With a 6.30am flight in the morning and 50 kilometres back to Bologna, it was a very nice gesture from Luca my host to take me for a special evening meal at a villa outside Modena.

I found it intriguing to be asked by several of the delegates, with my international training experience, where the best technicians are to be found. I responded including them with the very best, not just because of their technical fluency, but especially their mutual respect and co-operation with each other, sadly lacking with some in the UK.

Using Math
To conclude let’s look at an example of using Math to predict hydro mechanical function against rail pressure.
The system example; Bosch cp1h, volume control single point, solenoid injectors. Sample taken from stable idle, part load snap open throttle, return to idle.

Channel a blue;
Rail pressure profile idle, snap open, rtn to idle.

Channel b red;  
Volume control valve ground duty control

Channel c green;  
Volume control valve, current vis rail pressure

Channel d black;  
Air mass meter profile vis rail pressure

Math Channel purple;  
Math duty volume control

The focus of this analysis was to establish the rail pressure hydraulic response time against air mass load signal, expressing the primary control device, volume, as current and math duty conversion.

To understand the values in this test enables an unequalled understanding of the systems capability in delivering fuel vis time.
The next challenge is to sync a second 4 channel scope monitoring compression using WPS, with the 4-stroke cycle overlay, noting the secondary pressure increase when fuel is injected. Then we really are ahead of the curve.




can you feel the wheel?

Top Technician 2017 winner Karl Weaver is back, and looking at the active wheel speed sensor
Published:  25 May, 2018

I’m pleased to be writing a second article and this time I’ve decided to look at the active wheel speed sensor.
Originally electronic anti-lock braking systems (ABS) used magnetic inductive sensors to measure wheel speed. These are classed as ‘passive’ sensors and are actuated by a rotating toothed ring. The sensor contains a magnetic core w1 vith a fine coil of wire around it. As each tooth passes the sensor it generates an alternating current (AC) analogue signal. The faster the wheel goes, the greater the frequency and the higher the voltage. The wheel speed is determined by the frequency. The main disadvantage of this is the weakness of the signal at low speeds.  


No Smoking!

Karl Weaver tests the old adage ‘where there’s smoke, there’s possibly a problem with the mass airflow sensor…’
Published:  22 May, 2018

There’s nothing I love more than picking up an automotive magazine and reading a good case study. Occasionally they may be talking about a specific fault you’ve seen before. Sometimes as you’re reading through the symptoms and evidence you can’t help but make your own diagnosis and see if you were right.
    
The most engaging ones for me are when it’s not a common fault and you follow the diagnostic process of the writer. I find I always gain ideas and tips from a lot of these articles which assist me in improving my diagnostic success rate. In my previous articles I’ve emphasised the importance of training, whether it be in the classroom or via CPD. Another key thing is to learn from our mistakes and recognise our weaknesses. If we don’t do this, how do we improve?

Patterns
Over the years we have developed a good reputation for diagnostics which regularly brings in new customers. So when someone phones and says “I’ve got a light on and I’ve been told that you’re the man to see,” we have to make sure we get it right. When that sentence is closely followed by “my local garage has replaced some parts but the light has come back on,” we can quickly guess what’s coming next; “Can you fix it? I’ve already spent hundreds, how much is this going to cost me?” We’re not guilty for the previous garage’s failure to diagnose the fault but if we agree to take on the job we are compelled to get it right and so we should be. When you do get it right, is it necessary to stick the knife in the other garage’s back? Of course not! We always try to be positive and stick to explaining why we were successful with the repair rather than why the other garage failed. At this point you’ve already won the customer’s confidence in you.
    
So we learn from our mistakes and we can also learn from other people’s mistakes. With this in mind, over the last few months I’ve looked for a pattern in why misdiagnosis seems to occur. The obvious answer here is lack of training and skill but the frustrating thing with a lot of these jobs is if the technician had just stopped for a minute and thought about it, they probably would have found the fault.

Information
I’ve picked a handful of the last few jobs where this is the case and I’d like to share them as case studies.
    
The vehicle in question: 2012 Ford S-Max 2.0 Diesel. The customer’s complaint: Engine malfunction light on and lack of power. Previous work carried out: New genuine Ford mass airflow sensor fitted.
    
As always, we gathered as much information as possible from the customer. A key piece of information here was that the vehicle starts fine with no light on and performs normally until you accelerate hard or go uphill. He said his local garage plugged it in to their computer which told them it was the mass airflow sensor. They replaced this but it didn’t fix the fault.
    
We read the DTCs from the powertrain control module (PCM) and then road tested the vehicle to confirm the fault. The DTC was ‘P00BD-00 Mass or Volume Air Flow “A” Circuit/Range Performance – Air Flow Too High’ Yes, that’s a bit of a mouthful but there is an important clue in there. In this case we cleared the code just to make sure it returned when the symptom occurred which it did.
    
At this point there are several ways to go dependent on what you have access to.

Option one:
Log in to manufacturer’s technical portal and check for any bulletins relating to this code and maybe even download test procedures for it.

Option two:
Create your own test plan which should include inspecting and testing all components and systems that are linked to the engine air intake system.

Option three:
Load the parts cannon, aim and fire until the light stays out.

Someone has already tried option three  so let’s forget that. We don’t all have option one but I highly recommend having it in place as it can be extremely useful and save a lot of time...   

...We chose option two.

Sensors
As we were already on road test it was an ideal time to look at some PCM serial (live) data. We opted to look at the mass airflow sensor (MAF) and boost pressure sensor/manifold absolute pressure (MAP) sensors signals. Most diagnostic tools will give a ‘desired’ and ‘actual’ reading of MAP. Desired is the reading the PCM is requesting and expects to be seeing and actual is what is actually being measured. This regularly proves to be very handy when diagnosing any air/boost related faults. Straight away we could see that when you tried to accelerate, the actual boost pressure was considerably lower than the desired pressure. There are many possible causes of low boost pressure. We tend to start with a pressurised smoke test to the induction system. This is
a very effective way of finding both internal andexternal leaks.
    
We connected the machine directly after the nice shiny new mass airflow sensor (See Image 1 and Image 2), and within a matter of seconds we could see smoke coming from the intercooler area. A closer inspection revealed a split in the intercooler hose. A new hose was fitted and the vehicle was retested which verified a successful repair. I would love to be writing all about measurements taken with oscilloscopes and lots of technical stuff but it simply wasn’t necessary here.
    
Could the previous garage have fixed this one (see Image 3)? More than likely, yes! A thorough visual inspection to the induction system would have revealed it without the smoke machine due to the amount of oil residue around the hose.

Experience
The clue was in the DTC all along – ‘Air Flow Too High.’ It could mean that the air flow sensor is faulty and is reading too high but it’s important to stop and consider what could make the reading too high. In this case simply too much air flowing through it because it’s leaking back out the other side. Experience gives you the understanding of the PCM’s logic in what would make it flag that fault code. It’s also a fair point to ask why the DTC said “boost pressure too low.”
    
Experience has taught us that different manufacturers have different ways of saying the same thing and that is why I emphasise on reading the fault code carefully. For the same symptom some manufactures may use the fault code text ‘boost pressure too low,’ ‘boost pressure negative deviation,’ ‘turbine under-speed,’ the list goes on but this one: MAF/MAP correlation incorrect”’(seen on Land Rover) hits the nail on the head! The logic within the PCM relies on tables of pre-set data for comparison. It knows that if the engine speed ‘X,’ if the air mass entering the engine is ‘Y’ then the manifold pressure should be ‘Z.’ There is a set error tolerance either side to allow for slight deviation and when this is exceeded. For example, when air is passing through the mass airflow sensor but escaping before the manifold, then the DTC is set and as in most pressure related faults the engine power is reduced (see image 4).



THE WINNER TAKES IT ALL...

Getting ‘fit’ for summer and beyond, Barnaby Donohew examines how businesses can provide the kind of offering customers require
Published:  15 May, 2018

Workshop owners need to think hard about investment decisions. With that in mind, I’ve used my last two articles to look at a business management tool called value proposition design, which can help us to work out where to spend our cash.
    
We saw that it involves understanding our customers’ needs, which we do by identifying the jobs they want to achieve, and the positive and negative factors associated with them, respectively known as gains and pains. We then looked at how a business can identify products and services that might help customers complete their jobs, which, in turn, will either create the customers’ desired gains or relieve their undesired pains. These gain creators and pain relievers provide benefit to customers. Thus, investments in the right products and services increase our value proposition.
    
Our investment decisions are usually complicated by the fact that they can represent a chicken-and-egg situation: Money is needed to support the creation and delivery of products and services, yet profitable products and services are needed to create money (at the very least you will need to show that you will have good profitability if you are borrowing to fund your investment). As such, there are two measures of success of our value proposition: Whether it provides real value to our customers and whether it can be deliverable within a sustainable business model.
    
This article introduces a concept known as fit, which is the extent to which a company’s offerings match the needs of its target customers and are delivered within a sustainable business. Fit, therefore, represents the yardstick by which the success of a value proposition is assessed.
    
There are three levels of fit of a value proposition to a customer (segment) profile:

Problem-solution (‘on paper’)
If we take the value proposition discussed in my last article and check it against the customer segment profile created in the preceding article, we can check their fit. We do this by going through the pain relievers and gain creators one by one and checking to see whether they match a customer job, pain or gain. We can physically visualise this degree of fit by putting a check mark on each one that does (see Figure 1).
    
In this example, we have used our experience to the identify some jobs, pains and gains that customers might care about, and then created a value proposition to try to address them. However, at this point, we do not have any material evidence of the potential success of these products and services, gain creators or pain relievers. I.e. the fit is only evident on paper. The next step is to find evidence that customers care about the value proposition, or to start over designing a new one, if it is found that the customers don’t care.

Product-market (‘in the market’)
Once your products and services have been made available to customers, you will soon see whether they provide value to your customers and gain traction in the market place: customers are the ultimate, most ruthless, judge and jury of your products and services.
    
When assessing product-market fit, it is important to check and double-check the assumptions underlying your value proposition, i.e. have you correctly identified and prioritised the relative importance of the customer’s jobs, pains and gains? Have you provided things that customers don’t care about, and will you have to amend your value propositions, or start again?
    
Business model (‘in the bank’)
Your business model is the way your business is geared up to generate revenue and burn cash whilst you are creating and delivering a value proposition to your customers.
    
The search for business model fit involves reaching a state where you have a value proposition that creates value for customers (products and services they want) and a business model that creates value (profit) for your organisation. You don’t have business model fit until you can sustainably generate more revenues with your value proposition than you incur costs to create and deliver it.

Context
The potential value of our products and services, and the associated gain creators and pain relievers, doesn’t just depend on their match to the customer’s jobs, pains and gains. It also depends on the circumstances in which they are offered; i.e. their value is dependent on context.
    
For vehicle owners, an example might be the value of breakdown services. Have you ever signed-up for these from the hard-shoulder of a motorway? You’ll notice that you don’t get much of a discount. Those offers that you might have seen on the internet beforehand will suddenly seem pretty good value. These differences are because the breakdown service companies know full well that the perceived value of their services depends on context!
    
As such, businesses must identify the contexts in which their products and services will be offered. For example, a customer’s priorities will differ depending on whether they are broken down, have an expired MOT, need a replacement bulb in night time driving conditions, or are just booked-in for scheduled servicing etc. It is possible that each context might require its own value proposition.

Focus
For a customer having a given set of jobs and associated pains and gains, there are many ways a business might design a value proposition to achieve a fit. This is certainly true in our industry, in which there are many competing types of service and repair provider. Each has tweaked its value proposition to suit a given type of vehicle owner or context:

Independent workshops, often offering a large range of products and services as a kind of one-stop-shop to the ‘general’ motorist, usually aim to generate sufficiently high revenues by inspiring maximum loyalty from customers and trying to meet all their needs under one roof. These businesses require constant investment to provide the services necessary to keep-up-to-date with changes in motor vehicle technology and face a continuous challenge to monetise the value of every additional service.  Many diagnostic (or recalibration) services are still not well understood by customers, and workshops have to work hard to educate them, so that they can ‘appreciate’ their value. Convenience must also play a relatively significant part in their value proposition.
  
Fast-fit operations are all about convenience: Their customers can get in and out fast, without any notice, and, hopefully, with the minimum of disruption to their lives. The businesses require large stock inventories to ensure that there are no supply-related delays. By concentrating on only the fast-moving (the most commonly needed) products, these businesses can remain highly scalable and profitable: although they limit the scope of their products and services, to reduce costs, their sales volumes allow them to retain considerable buying power. Their customers love the convenience and prices they can offer given the buying power (and increasing integration with the parts supply chain) that the larger fast-fit chains have. Main dealers, I think, rely more on social or emotional pains and gains to draw in their customers (e.g. think about the image they work hard on purveying or the potential manipulation of customer perceptions of safety, both driven by presenting themselves as the most qualified to work on a given make of vehicle). They need to work hard to offer convenience (e.g. courtesy cars, rapid turn-around, customer/vehicle pick-up or drop-off etc.) as their dealerships, geographically-speaking, are relatively sparsely distributed amongst the population. Some vehicle owners (ironically, those most likely to buy their next vehicle from a dealership) will also be concerned with the resale value of their car and may seek to maintain a full dealer service history to try to maximise its value.
    
Following the above, broadly-defined, categories of businesses, there comes specialists, offering a smaller range of products and services to increasingly niche customer segments or contexts: e.g. independent specialists (single-make specialists combining aspects of both the independent workshop and main-dealer value propositions), diagnostic specialists (as with breakdown and recovery specialists, when you need them, you need them – and they should charge accordingly), component-repair specialists (e.g. transmission specialists).
    
Then there is the remaining plethora of value propositions available to vehicle owners: breakdown and recovery services (apart from their normal role helping those in distress, I’m sure they would agree that they also play a role in repairing vehicles for those that place no value whatsoever on preventative maintenance…); mobile technicians (perhaps offering the ultimate in convenience in certain contexts?); and, my favourite, the chancers (that bloke in the pub who once changed a side-light and now thinks he can charge an equally stupid idiot to fit a new timing chain for them…).

Future
We’ve seen from the above that a stack of value propositions is competing for our vehicle-owning customers. As such, our value proposition design work and derived knowledge, can inform a strengths, weaknesses, opportunities and threats (SWOT) analysis of our business. So far, all these competing businesses have managed to co-exist and thrive within an industry that is set-up to offer value to private vehicle owners. However, take a look at Figure 1 again – what might be arriving in the future that could represent a threat to not only an independent workshop but the entire sector? How about Vehicle-as-a-Service (VaaS), a.k.a. car-on-demand? This single value proposition removes an awful lot of the hassle of vehicle ownership (equivalent to automotive morphine…) and provides many gains. In fact, it is so disruptive that it removes/changes the very nature of the customer segment; vehicle ownership becomes almost redundant. Should it be a surprise that one of the few barriers to widespread adoption of VaaS (the convenience of making short, necessary, journeys, e.g. to pick up milk when nearby shops are closed) is being addressed by a company that is seeking to provide VaaS: i.e. Amazon whom are also developing drone delivery systems?
    
When it comes to the ultimate value proposition, may be there can be only one.
    
I’ll leave that thought with you.



Put the pedal to the metal

Frank Massey looks at the practicalities of future transport with an engineer’s eye, and points out some potholes in the road ahead
Published:  14 May, 2018

I have spent most of my life repairing things that are broken and the rest of it trying to prevent it happening in the first place. This year, June to be precise, will be my 50th year in the automotive industry; I have witnesses and have embraced incredible advances in technology.
 
This article may appear somewhat negative, perhaps even misinformed and out of touch. Have I lost the plot? Before judging my motives let me explain how I think and react to change. I think I have already proved my ability to embrace technical evolution. Fixing a problem for me should be a well thought out long term positive step forward; Understanding the immediate challenges whilst focusing on the cause and not reacting to the symptoms. I would like to think of myself as a thinking engineer.

Developments
I am referring to current automotive developments, specifically autonomous and battery powered vehicles. We have just witnessed the first death by an automonous vehicle, the litigation should be interesting. Who is responsible? The driver? He was in full autonomous mode! The vehicle manufacturer? How about Microsoft? and we have all just witnessed how software companies respond to problems! Back to the driver then.

If you genuinely believe this is a step forward ask your self this question; would you take your family on holiday with no pilot in the cockpit? After all, aircraft have some of the most comprehensive and competent automonous systems.
Second on my list are battery powered vehicles. Let me present facts that support my position. The problem- pollution of the atmosphere. The cause- hydrocarbon fuelled vehicles. Battery powered vehicles will drastically increase the requirement on electricity generation, with most countries using hydrocarbon fuelled power stations! Limited distance and the uncertainty of charging port availability, notwithstanding the unwelcomed journey delays, is in my opinion
not a sensible answer to flexible mass transport.
 
The UK has marginal spare capacity in power generation, imagine if 25% or more of the UK car parc plugged in at 6pm. The national grid does have strategies for sudden increases in demand. These include bringing old standby stations online and increasing imported supplies. I accept these considerations are partly personal
and emotional. However, look at a more interesting set of problems facing the vehicle manufacturers,
such as lithium reserves and the geo-physical locations.
 
Currently the average energy consumption of battery vehicles is 65kw/hr. This requires 10kg of lithium per battery. Tesla expects to produce 500,000 vehicles by 2020. This would require 5,000,000 kg or 5,000 metric tons, per year, of refined lithium. Discussions are under way for production of reduced performance vehicles requiring less lithium.
Research estimates global reserves of 365 years assuming the current 37,000 metric tons production per year. Current lithium demands are split 30/30% with battery and ceramic production. However, it is also predicted that around 100 mega capacity battery plants, like Tesla will be required to meet demand globally.  Global EV estimates of 100,000,000 vehicles by 2040 would require 800,000 metric tons of lithium per year. Divide this by the estimated 40,000,000 metric tons global reserves leaves a timeline of 18 years.

Demand
Demand is a variable that cannot be accurately predicted. For example, China’s population of 1.3. billion, already has 50% of the vehicle ownership of the USA. With India and other emerging economies coming on-stream, vehicle growth could exceed all predictive estimates.

Where is the electricity going to come from? Greece for example has a EU emission get-out clause as all its energy production comes from vast open cast coal mines.

Recycling cost is around five times  that of new production cost, with around a 20:1 lithium recovery ratio.
The lithium atomic symbol Li is the third lightest solid in the periodic tables. Highly flammable, it is also used as solid fuel rocket boosters and torpedoes. It is also used as an initiator for triggering nuclear weapons. With more down to earth requirements, lithium is used in heat resistant glass, grease, ceramics, and iron steel production. These requirements exclude all other uses of lithium, from your mobile phone battery to those nice kitchen tiles your wife has chosen. So back to my proposition, dealing with the problem and not the symptoms! Batteries are not the answer. I’m no physicist, but I see the hydrogen cell as the only current hope on the horizon for flexible mass transport.

A much-improved public transport infrastructure, a more realistic vehicle operating tax structure will all play a part in vehicle ownership within the developed economies. We cannot expect emerging nations such as China and India, with around two billion people, to follow suit any time soon.

As a keen cyclist from the age of 15, with a mild asthmatic condition I’m as focused as anyone on reducing global emissions. Judging by the way so many motorists still drive their vehicles, the reality shock of what’s coming cannot be far away.



How can you test what you can't see?

John Batten shows how you can never be complacent about skills, as you always need to be ready for what might come through the door
Published:  30 April, 2018

Life as a business owner can often be as challenging as it is rewarding, in fact overcoming these challenges is half of the reward for many, especially when it comes to accurately diagnosing the undiagnosable.
    
Many businesses build a reputation locally on the fact they’re able to find faults that others can’t. This acts as a point of differentiation, which is great. Developing this reputation in your locale can pays dividends, as customers become less price focused when they know why you’re different to your competition.
    
What a great place to be. Your customers love you because you’re effective in your diagnosis and you get paid well for doing this. What’s not to like about that? Not a lot!

Sounds great but…  
 
If it were that easy, everyone would be doing it. Easy? Definitely not, but then anything worth achieving never is. Here’s the deal though – It’s not difficult either, although it does take some deliberate thought on the part of the business owner. The kind of technical success that’s required for a reputation like this is within the grasp of all garage owners; It just takes the commitment to change and a willingness to plan for the change required.

The owner is clearly responsible for the health and continuing success of their business, but with so much demand on their time creating a technical team to differentiate your business from your competition is not always at the forefront of their mind.

The best time to plant a tree…
Was 20 years ago. The second best time is now. As proverbs go that one hits the mark when it comes to developing anyone within your business. The question is, where to start?
    
Skills analysis is a good a place as any. What skills do your technical team currently possess? Do you have a team of technical superheroes today and just need to turn on the marketing tap to increase your bottom line numbers? Or do you have a hero in the making and need to take a look at the training required before you buy them a cape? If you’ve a hero in the making then that’s great! There’s nothing more satisfying for a technician and the business owner when they embark together on a symbiotic journey of development. The technician will feel invested in and the owner will have a stronger team and be able to promote their newfound skills increasing efficiency and profit. A win-win for everyone!
    
So you’ve got your training plan in place and the technical skills of your team are moving in the right direction. Time to put your feet back up on the desk? Not quite. Continued success means that not only do you need to be able to efficiently repair what’s in your workshop today, but see what’s coming over the hill and ensure you have the skills and equipment for tomorrows car park.

I’m sure you’ve heard diesel fuel being called into question as a long term option for powering our vehicles and that we’ll all be driving dodgems (or some other electric vehicle) as the future of motoring. But is there an alternative that has both a foot in today and an eye on tomorrow? Oh yes, I’d almost forgotten… It’s petrol. More specifically gasoline direct injection (GDi).

The ‘new old’ technology
GDi has been with us for some time and in reasonable quantities since the early noughties. This means there are bucket loads of these vehicles in your workshops daily. Not only that, but manufacturers are looking at the benefits of taking rail pressure in excess of 500 bar and how this may help with emission reduction. What does this mean for you? Well. If your not sure how to effectively diagnose these vehicles then there’s no better time to learn. Plus it’s probably here for some time to come. With that in mind it shouldn’t come as a surprise that my technical article this month is a 2L GDi Audi A3.

No time to hesitate
The customer complaint on this vehicle was a rough idle and hesitant pick up on light throttle. Following my own mantra, I started Johnny’s 15-step diagnostic process with a thorough questioning of the client whilst experiencing the issue with them. It was indeed ‘stumbly’ (believe it or not that is a technical term – in my world anyway) and I followed this with a look at fault codes and inspected serial data. There was nothing to write home about here, neither was there with the tests for mechanical integrity or ignition diagnosis. So where does that leave us? Just fuelling.

Under pressure
With just fuelling left as the option for our hesitation low and high-pressure systems were evaluated and again no fault found, that just left injection quality or quantity.
    
GDi Injectors differ from manifold injectors not only in their position (GDi injecting straight into the cylinder) but also in their electrical characteristics. The high current driver (10 Amps, see figure 1) enables fast multiple injections not dissimilar to that of solenoid diesel injectors. All injectors were inspected electrically and again no fault found. We were fast running out of test options for fuelling... What to do?

How can you test what you can’t see?
We had seen similar issues before and figured I’d try and identify a dribbly injector (there I go getting all technical again) prior to its removal from the cylinder. We ran the engine and stopped it, isolated the breather system and removed a spark plug, then tested for HCs in each cylinder waiting for a drip and a rise in HCs. What did we find? Nada, Zilch, Nothing! There was nothing for it the injectors would have to come out and be tested.    
    
It just so happens were fortunate enough to have a Carbon Zapp test bench in the training center. This gives us the capability to test GDi injectors at high pressure. It’s a cool piece of tech that runs the injector through an automated test plan, giving a pass/fail report on the injection characteristics. After testing each injector I was delighted to find one
of these was defective and the fault found.
    
If you’d like to see the injector being bench tested then head over to www.autoiq.co.uk/blog where you can watch a video. So there we go another car fixed, and I’m sure this happens in your workshop on a daily basis. But here’s a question for you: Do you have a program of technical development to help your team work efficiently? And can you differentiate your business from those around you? If it’s a yes to both then brilliant, you’re set for the future! If not then give me a call at Auto iQ on 01604 328500 and I’ll be only too pleased to help your business develop a plan for your continued success.





A shock to the system and how to avoid it

EVs and hybrids represent a real opportunity, but training is vital for businesses looking to stake their claim on the future
Published:  24 April, 2018

Hybrid and electric vehicles (H/EVs) are an ever-day reality, and are becoming more popular with drivers and carmakers.
“Electrified powertrains are emerging as manufacturers’ preferred means of meeting stringent future emissions legislation,“ says Jonathan Levett, technical trainer for Delphi Technologies Aftermarket.


Choosing a scope

Frank Massey scopes out what technicians should look for when picking a oscilloscope
Published:  18 April, 2018

Having just completed a foundation oscilloscope course this weekend, it became very apparent that a large number of technicians in our industry lack good advice in both choosing and using cutting edge diagnostic tools.


It’s all very Scopetastic!

John Batten points out the magical power contained in the scope that could be helping you with diagnostic spells every day
Published:  02 April, 2018

It’s been an interesting few weeks here at Auto iQ HQ. After my last article discussing the merits of “growing over buying” technicians I received a few phone calls looking for my views on the most productive path to technical enlightenment.


Part five: Electric and hybrid vehicles

In the fifth part of his look into EV and hybrid technology Peter Coombes of Tech-Club continues to look at electric motors
Published:  02 April, 2018

We previously looked at the basic principles of brushless electric motors that use an alternating current to continuously reverse or swap the polarity of the magnetic field in the stator. However, for many high power applications including electrically propelled cars, the motors are supplied with a 3-phase alternating current rather than just a single alternating current.


Part two The good and THE GREAT

In the second part of his series, Ian Gillgrass shows how following the diagnostic process can turn a good technician into a great
Published:  26 March, 2018

In part one, we looked at the start of the ‘diagnostic process.’ The first steps were customer questioning, confirming the fault and knowing the system and its function. These help the technician to build the ‘big picture’ necessary to repair the vehicle correctly.
In this article we will look at the next four steps.

Step 4: Gather evidence
It is easy to overlook this step as many technicians think of it as the overall ‘diagnosis.’ However, once the technician understands the system, gathering evidence will provide key information. This step is normally best carried out with the use of test equipment that does not mean the dismantling of systems and components.

Many technicians have their own favourite tools and equipment but this list can include (but not limited to)
the following:
Scan tool – It is always best practice to record the fault codes present, erase the codes, and then recheck. This means codes which reappear are still current. Remember that a fault code will only indicate a fault with a circuit or its function. It is not always the component listed in the fault code that is at fault

Oscilloscope – An oscilloscope can be used for a multitude of testing/initial measuring without being intrusive. Some oscilloscope equipment suppliers are looking at systems within high voltages hybrid/electric vehicle technology. The waveforms produced by the test equipment can be used when analysing the evidence and may indicate that a fault exists within a system. An understanding of the system being tested will be necessary to understand the information. This may even include performing sums so all those missed maths lessons at school may come back to haunt you. It may take time to become confident analysing the waveforms, so be patient

Temperature measuring equipment – This can include the use of thermal imaging cameras. Most systems that produce energy/work will also produce some heat. The temperatures produced vary from system to system. Examples include everything from engine misfires to electrical components, as well as air conditioning system components and mechanical components such as brake and hub assemblies. The possibilities are endless and results can be thought provoking.

Emission equipment – By measuring the end result, an exhaust gas analyser can show you if the engine is functioning correctly. The incorrect emissions emitted from the exhaust help indicate a system fault or a mechanical fault with the engine

Technical service bulletins – Many vehicle manufacturers produce technical service bulletins (TSBs) that are generated by a central point (usually a technical department) from the information that is gathered from their network of dealers. Some of these may be available to the independent sector either through the VM or through a third party – It’s always worth checking if these exist. They may indicate a common fault that has been reported similar to that the technician is facing. Some test equipment suppliers may provide TSBs as part of a diagnostic tool package

Software updates – Many vehicle systems are controlled by a ECU. Most vehicle manufacturers are constantly updating system software to overcome various faults/  customer concerns. Simply by updating the software can fix the vehicles problem without any other intervention of repairing a possible fault. This is where having a link to a vehicle manufacturer is vital in repairing the vehicle

Hints & tips – Most technicians will have a link or access to a vehicle repair forum where they can ask various questions on vehicle faults and may get some indication of which system components are likely to cause a vehicle fault

Functional checks – Vehicle systems are interlinked and typically share information using a vehicle network. The fault may cause another system to function incorrectly, so it is vitally important that the technician carries out a functional check to see if the reported fault has an effect on another system. By carrying out this check the technician again is building the big picture

Actuator checks – Most systems today are capable of performing actuator tests. The technician can perform various checks to components to check its operation and if the system ECU can control the component, often reducing the time to the diagnosis, by performing this task the technician can identify whether it is the control signal, wiring or component or it is sensor wiring. This function can be used in conjunction with serial data to see how the system reacts as the component functions

Serial (live) data – The technician can typically review a vehicle system serial data through a scan tool. Having live data readings to refer to can help you review the data captured. Using actuator checks and viewing the serial data can also help the technician to identify a system fault

Remember to record all the evidence gathered so it can be analysed during the next step in the diagnosis. We can’t remember everything. If the technician needs to contact a technical helpline they will ask for the actual readings obtained recoding the data gathered will help.

Step 5: Analyse the evidence
Analysing evidence gathered during the previous steps can take time. The technician needs to build the big picture from all the evidence gathered during the first few steps. You need to analyse the information gathered, and decide on what information is right and wrong.

This step may rely on experience as well as knowledge on the product. You should take your time – don’t be hurried. Time spent in the thinking stages of the diagnosis can save time later. Putting pressure on the technician can lead to errors being made. It may be necessary to ask the opinion of other technicians. If the evidence is documented it may be easier to analyse or share between others.

Step 6: Plan the test routine
After analysing the evidence gathered it’s now time to start to ‘plan’ the best way to approach to the task or tasks in hand.

The technician should plan their test routine, decide on what test equipment should they use, what results are they expecting, if the result is good or bad  and which component should they test next.

Document the plan – this enables you to review decisions made at this stage in the next step. The technician may not always get it right as there may be various routes to test systems/components. The test routine may have to be revisited depending on the results gathered during testing. Documenting the test routine will provide a map.  Also, don’t forget to list the stages, as this is something that could be incorporated into an invoicing structure later.

The technician should indicate on the routine what readings they expect when they carry out the system testing. This can be generated by their own knowledge/skill or the expected readings may come from vehicle information which they have already sourced. If the information is not known at the time the test routine is planned, then the test routine may highlight what information is required and what test equipment is needed. You shouldn’t be afraid to revisit the plan at any time and ask further questions on which direction the tests should take. If the plan is well documented and the technician becomes stuck at any point, they can pause the process and revisit later. Also the information can then be shared with various helplines that support workshop networks.

Step 7: System testing
The technician then follows their pre-determined plan, if it is documented they can record the results of the test(s) as they follow the routine.

Many technicians tend to go a little off-piste when they get frustrated. Having the routine documented can keep the technician on track and focused on the result. If the routine is followed and the fault cannot be found the technician may have to go back to the analysing the evidence or planning the test routine. The technician shouldn’t be scared of going back a few steps, as I said previously analysing the evidence takes practice and can be time consuming, not to be rushed.
    
Summing up
Remember to follow the process. It is easy to be led off track by various distractions but don’t try to short circuit the process. Some steps may take longer than first thought to accomplish than others. Some distractions may be outside of your control, and it may be necessary to educate others. Practice, practice, practice. Refine the process to fit in with your business and its practices, the business could align its estimating/cost modelling to the process, being able to charge effectively and keeping the customer informed at each stage of the process.

Coming up...
In the next article I will be looking at the next four steps which are; Step 8: Conclusion (the root cause), Step 9: Rectify the fault and Step 10: Recheck the system(s). The last article in this series will indicate the final three steps and how to fit them all together in order to become a great technician and perhaps succeed in Top Technician or Top Garage in 2018.




Ignite your interest in ignition

A pair of problematic Audis reignite Frank’s longstanding interest in ignition issues
Published:  19 March, 2018

This month’s subject was prompted by a recent conversation with a colleague in Australia. The conversation included an invitation to a technical festival in October, where it was said that ignition would be one of the subjects of interest. Many years ago, when I began developing our training programme, ignition was a subject of primary concern when diagnosing gasoline
engine problems.

This is a complex subject often not fully understood and often overlooked. Its vital importance recently became apparent in our workshop, when we were presented with two Audi rs6 engine failures. One failure has yet to be investigated the other suffered piston failure due to combustion faults.

The increasing complexity of homogenous and stratified fuelling, split injection delivery and variable valve timing geometry has placed critical responsibility on ignition performance. Often within the diagnostic process there is no serial evidence of an ignition problem, or that what evidence is available is incomplete especially at the early stages of failure. The process has not changed in over 30 years;  You must scope it.

Process overview
So here is an overview of the process. Firstly, you must understand that it requires a specific amount of energy to completely combust the air fuel charge. Ignition energy is measured in joules, our task it to ensure the energy is created and delivered correctly. The primary circuit bears the responsibility of energy creation with current profile as the focus of our measurement. The secondary circuit has the responsibility of delivery, our focus is burn time and slope profile.

I accept that both circuits have a shared responsibility at the point of induction where energy within the primary is transferred into the secondary. The physical challenge is the method of accessibility. With static or direct ignition it is often not possible to connect to the coil primary circuit, leaving the option of induction as the method of measurement. The primary will always have a power and switched ground, so current measurement using a suitable hall clamp is always possible.

Diagnostic observations
The four critical diagnostic observations in order of priority are:
 
Ignition burn time measured in milli-seconds with a range of 1-3ms depending on ignition type. Do not assume length of burn relates to energy value Primary current profile with a range of 3amps (points ignition) 20amps static ignition. Note the expression profile, it includes rise time and rate of collapse Coil ringing, this is the resonance at the end of the burn event it represents the small residual ignition energy returned in to the coil secondary winding Firing line voltage, this represents the value of electrical pressure in delivering the induced energy to the spark plug electrode it includes all components in the delivery process

You must also understand that the performance of the injector, cylinder turbulence, and mechanical efficiency forms part of the combustion process. Intake air temperature, pumping losses and fuel quality all affect the burn process. Let’s begin with the tool I distrust the most! Serial data is a good first look – there is some very useful information such as cylinder misfire count, ignition timing individual timing retard data, air intake temperature and exhaust temperatures. There may also be additional data on burn time and primary charge time, but I don’t trust or rely on it.

So, out with my Pico scope. Connectivity can be a challenge, over the years we have built our own probes, however, if the manufacturers can run a circuit there you can scope it. There is a simple logic process.  Begin with burn time, look at the duration and slope it – It should be roughly parallel with the horizon.

A rising line confirms a difficult transition of energy across the electrode. Lean combustion, glazed plug, cylinder pressure, plug performance. Cylinder turbulence.

A falling slope represents the opposite condition; low cylinder pressure, fouled or shunting plug circuit, small plug gap. The burn profile should be relatively smooth, a turbulent burn path confirms difficult in cylinder conditions. It can and does point to injector fuel delivery problems especially if a sharp rise at the end of the burn time is present.

You may appreciate now just how vital scope evaluation is.

Primary current path confirms good power supply and the performance of the power transistor in its ability to switch and hold load to ground. Note the rise time characteristics and the off switch, under shoot here is a good indication. If you can, observe primary voltage. Note the slow rate on load, it’s the slow rise in voltage during coil charge time, a problem here will affect current flow so go for current first its easier to understand. Remember one of my core diagnostic rules; If it moves, gets hot, or applies a load measure current!

Coil ringing is the inverted energy returned into the coil secondary. With no path to ground,  it gradually gets weaker, converting its energy to heat. Expect 2/3 rings in current systems. If the coil windings are compromised in any way a reduction in inductance will follow. The rings will disappear, ignition energy may still be present but a reduction in value will result. Be warned this condition will never be known if not scoped and critical engine failure often follows.

Firing line voltage can only be measured accurately in primary to be honest. Expect the following values:; Conventional rotating ignition 50v, wasted spark ignition 40v, direct ignition30v; Plus or minus 5 v on all values. The problem with exploring this with a coil probe is that the probe attenuation is not known, so its difficult to scale.

I hope this helps. It is a very complex subject , often neglected and overlooked.

Just before I go here is a challenge; How many information systems, VMs especially, don’t give these four  vital statistics? So how do they know if there is a problem?




All the things YOU could do…

Barnaby Donohew looks at options to strengthen and future-proof your business, if you had a little money
Published:  14 March, 2018

If you had a little money, how would you spend it to improve your business? Maybe you’d buy the latest ADAS calibration kit, or subscribe to an workshop management system?

Okay, now let’s think bigger. If you were given all the money you had ever invested in your business and could start it again from scratch, how would you gear it up to attract customers and make it profitable? Would you build something like
your current business, or would it be totally different?

Why do I ask? Because the world changes quickly, which means our businesses are rarely set up exactly as we need or want, and we must make frequent spending decisions. We must work out how to prioritise our spending, to ensure we always offer the things of greatest worth to our customers; i.e. we maximise our value proposition.

Last month, we sought to understand our typical customer (a private vehicle owner). We saw that they have functional, emotional and social tasks to complete (jobs). These jobs have either good results (gains), or bad outcomes, risks and obstacles, related to their undertaking or failure (pains). For example, taking a car to the workshop is an extreme pain for a typical customer because it makes it more difficult for them to complete their more important jobs (e.g. commute to work or navigate the school run).

This month, we’ll use the things we learned about our customers to design our value proposition; We’ll use a repeatable technique to ensure our businesses offer the things our customers need and want. The result will be a value (proposition) map, or value map for short.

Value mapping
Anything that helps our customers get their jobs done will have value. Therefore, our products and services must aim to help them complete their jobs. If these products and services then eliminate a customer’s pains, they are pain relievers, or, if they produce gains, they become gain creators. By stating the ways in which our products and services create gains and relieve pains, we can communicate their potential benefit to our customers. Hence, by putting a list of our products and services together with the lists of their respective pain relievers and gain creators, we create a guide to the worth of our business to our customers. That is, we make a value map.

Of course, not all our products and services, and their subsequent pain relievers and gain creators, are equally relevant to our customers; some are essential, whilst others are merely nice to have. We can use these differences to help our decision making: by ranking the items in our value map in their order of relevance to our customer, we can see which can be ignored, and which can be prioritised.

Figure 1 shows example items that might be within an independent workshop’s value map, ranked in order of relevance to a private-vehicle-owning customer (a value map is targeted at a specific customer segment). As with the creation of a customer profile, there is no ‘right’ answer; this one is based on my half-thought-through assumptions, and previous business experiences. Yours might differ. Hence, we must derive and tweak our respective value maps accordingly. Ultimately, each of us would use business metrics (e.g. profit ratios and customer satisfaction ratings) to tune our value propositions to the max. But that’s a task for another time.

Products and services
We saw before that customers don’t like to waste time at a workshop; they want to go through their lives with the minimum of hassle. They crave convenience. Therefore, courtesy cars, a handy location (covered under ‘community-orientated’ services in Figure 1), extended opening-hours, while-you-wait servicing, or pick-up and returns (either vehicle or customer) all represent high value offerings. We don’t have to offer them all - they’re included in Figure 1 for reference. Likewise, online bookings and related management systems simplify engagement, bring convenience, and enhance value.

Have you ever heard a customer say they like messy and dirty workshops and technicians? I haven’t. That’s because we attach value to our health and safety: If your premises and staff are well presented, they will project professionalism, and your customers will reach their desired emotional state of feeling safe. Even better, properly motivated, well-equipped and trained staff will increase the likelihood that your customers are safe and secure. As safety fears are powerful motivators and manipulators, we must use our expertise to help our customers assess and manage their exposure to risks. They will then be in control and feel in control of their safety.

Not all customers will be seeking to cut costs all the time, but certainly all of them will want to control their costs. There are ways a business can help customers manage this aspect of their lives: clear terms of trade and fee structures; well-managed engagements with expert advice; warranted parts and labour; and a range of payment methods such as easy-pay solutions, touch-less, or credit card services.

Surprisingly, some customers want to look after their vehicles. Primarily, this helps them feel safe and secure, minimises the risk of disruption to their lives (from breakdowns), and protects the value of their vehicles. A good service history represents monetary value in this sense. This means we should be offering, high quality parts and labour, and OE-aligned servicing and repairs.

Pain relievers
It might suit your ego to think all your customers visit your workshop because of your skill, expertise and professionalism, or your friendly welcome and great (i.e. free) coffee. However, pure convenience can be the decisive factor when some customers choose where to take their vehicles: you’re around the corner; you had a spare courtesy car; you’re open; you were prepared to look at it there and then; you had the part in stock etc. Whilst this reflects the significant value these pain relievers offer to all our customers, it is the case that some of those who value convenience above all else are not able to see the worth of your other products and services. If they don’t understand that your conveniences come at a cost, then point them elsewhere. You will never please them. Nothing has the potential to sour a relationship like an unexpected bill: When my head was buried in an absorbing diagnostic job, adequate communication was sometimes an issue for me. My ‘solution’ was to swallow the costs, to avoid upsetting the customer. This was neither a solution nor a sustainable business strategy. What I really needed was the best preventative medicine of all: Great communication.

It should be no surprise that there are far more pains than gains in our value map: Servicing and repair workshops are all about pain relief; we are either trying to eliminate a current pain, through diagnostics and repairs, or carrying out preventative maintenance to avoid a future pain. Because this is our reason for being, customers find it intolerable to think our actions have caused them unnecessary inconvenience or costs. Nowhere is this more obvious than when we try to ‘help them out’ -  Every time we ever tried to help a customer to control costs (i.e cut costs), by fitting a cheaper part or trying a less expensive solution, it always backfired. Every single time. Can you guess who suffered the consequences? It always paid us better to ensure the car was fixed when it left the workshop. ‘Try it and see’ tends to translate into ‘you are going to be really cheesed off next time I see you’, It also counted that we supplied quality, parts and labour.

Gain creators
When properly delivered, our products and services will help our customers have the following: An easy-life; a car that holds its value and works properly; peace of mind; a sense of feeling special at our premises; and the information from our sound advice to make good decisions.

However, for some of us, the ultimate convenience is to not have to engage our brain, so if we really want to take our value proposition to the next level, we must be highly proactive and perform our customers’ thinking for them: e.g. by sending MOT and service reminders, with easy to process ‘calls to action’ so that they are only a click away from being sorted. Then, at the allocated time, we would pick-up their vehicles from their homes to take them to the workshop, leaving a replacement vehicle in their place. I know plenty of businesses that do this. And they are successful.

Money, money, money
There are many servicing and repair options available to private vehicles owners: Independent workshops, fast-fit chains, main-dealer workshops, mobile technicians, chancers, etc. Next time we’ll see how other business types deliberately tweak their offerings (value maps) to fit specific customer segments. We need to learn to be equally deliberate and well-informed about our investment decisions. What if we don’t? Well, we might waste all our money, and lose all our customers. Which isn’t always funny, even in a rich man’s world.


https://automotiveanalytics.net


How to create diagnostic superheroes

With diagnostic power comes great responsibility: John Batten finds that the best technicians are not born – they are made
Published:  05 March, 2018

Have you ever had that sinking feeling? You know the one. It’s 08:30 on Monday morning and your best technician is walking towards you with a forlorn look and an envelope in his hand.


technologies of electric and hybrid vehicles

In the third part of his look into EV and hybrid technology Peter Coombes of Tech-Club looks at the challenges of recharging EV batteries
Published:  17 February, 2018

In the previous two issues, we looked at the way batteries store energy. We could in fact compare a battery to a conventional fuel tank because the battery and the tank both store energy; but one big difference between a fuel tank and a battery is the process of storing the energy. Petrol and diesel fuel are pumped into the tank in liquid/chemical form and then stored in the same form. Meanwhile, a battery is charged using electrical energy that then has to be converted (within the battery) into a chemical form so that the energy can be stored.

One of the big problems for many potential owners of pure electric vehicles is the relatively slow process of
re-charging the batteries compared to the short time that it takes to re-fill a petrol or diesel fuel tank. If the battery is getting low on energy, the driver then has to find somewhere to re-charge the batteries, and this leads to what is now being termed ‘range anxiety’ for drivers.

Whilst some vehicle owners might only travel short distances and then have the facility to re-charge batteries at home, not all drivers have convenient driveways and charging facilities. Therefore, batteries will have to be re-charged at remote charging points such as at fuel stations or motorway services; and this is especially true on longer journeys. The obvious solution is a hybrid vehicle where a petrol or diesel engine drives a generator to charge the batteries and power the electric motor, and for most hybrids the engine can also directly propel the vehicle. However, much of the driving will then still rely on using the internal combustion engine that uses fossil fuels and produces unwanted emissions. The pure electric vehicle therefore remains one long term solution for significantly reducing the use of fossil fuels and unwanted emission, but this then requires achieving more acceptable battery re-charging times.

Charging process and fast charging
Compared with just a few years ago, charging times have reduced considerably, but there are still some situations where fully re-charging a completely discharged electric vehicle battery pack can in take as long as 20 hours.  It is still not uncommon for re-charging using home based chargers or some remote chargers to take up to 10 hours or more.

Although there are a few problems that slow down charging times, one critical problem is the heat that is created during charging, which is a problem more associated with the lithium type batteries used in nearly all modern pure electric vehicles (as well as in laptops, mobile phones and some modern aircraft). If too much electricity (too much current) is fed into the batteries too quickly during charging, it can cause the battery cells to overheat and even start fires. Although cooling systems (often liquid cooling systems) are used to help prevent overheating, it is essential to carefully control the charging current (or charging rate) using sophisticated charging control systems that form part of the vehicle’s ‘power electronics systems.’

Importantly, the overheating problem does in fact become more critical as battery gets closer to being fully charged, so it is in fact possible to provide a relatively high current-fast charge in the earlier stages of charging; but this fast charging must then be slowed down quite considerably when the battery charge reaches around 70% or 80% of full charge. You will therefore see charging times quoted by vehicle manufacturers that typically indicate the time to charge to 80% rather than the time to fully charge. In fact, with careful charging control, many modern battery packs can achieve an 80% charge within 30 minutes or less; but to charge the remaining 20% can then take another 30 minutes or even longer.   

Battery modules
Many EV battery packs are constructed using a number of individual batteries that are referred to as battery modules because they actually contain their own individual electronic control systems. Each battery module can then typically contain in the region of four to 12 individual cells.  One example is the first generation Nissan Leaf battery pack that contained 48 battery modules that each contained four cells, thus totalling 192 cells; although at the other extreme, the Tesla Model S used a different arrangement where more the 7,000 individual small cells (roughly the size of AA batteries) where used to form a complete battery pack.

The charging control systems can use what is effectively a master controller to provide overall charging control. In many cases  the electronics contained in each battery module then provides additional localised control. The localised control systems can make use of temperature sensors that monitor the temperature of the cells contained in each battery module. This then allows the localised controller to restrict the charging rate to the individual cells to prevent overheating. Additionally, the localised controller can also regulate the charging so that the voltages of all the cells in a battery module are the same or balanced.

One other problem that affect battery charging times is the fact that a battery supplies and has to be charged with direct current (DC) whereas most charging stations (such as home based chargers and many of the remote charging stations) provide an alternating current (AC). Therefore the vehicle’s power electronics system contains a AC to DC converter that handles all of the charging current. However, passing high currents through the AC to DC converter also creates a lot of heat, and therefore liquid cooling systems are again used to reduce temperatures of the power electronics. Even with efficient cooling systems, rapid charging using very high charging currents would require more costly AC to DC converters; therefore, the on-board AC to DC converter can in fact be the limiting factor in how quickly a battery pack can be re-charged. Some models of electric vehicle are actually offered with options of charging control systems: a standard charging control system which provides relatively slow charging or an alternative higher cost system that can handle higher currents and provide more rapid charging.

Home & Away
One factor to consider with home based chargers is that a low cost charger could connect directly to the household 13-amp circuit, which would provide relatively slow charging of maybe 10 hours for a battery pack. However, higher power chargers are also available that connect to the 30-amp household circuits (in the same way as some cookers and some other appliances); and assuming that the vehicle’s AC to DC converter will allow higher currents, then the charging time could be reduced to maybe 4 hours operate (but note that all the quoted times will vary with different chargers and different vehicles).

Finally, there are high powered chargers (often referred to as super-chargers) that are usually located at motorway services or other locations. These super-chargers all provide much higher charging currents to provide fast-charging (as long as the vehicle electronics and battery pack accept the high currents); but in a lot of cases, these super-chargers contain their own AC to DC converter, which allows direct current to be supplied to the vehicle charging port. In effect, the vehicle’s on-board AC to DC charger is by-passed during charging thus eliminating the overheating problem and the high current DC is then fed directly to the battery via the charging control system.

In reality, the potential for re-charging a battery pack to 80% of its full charge in 30 minutes or less usually relies on using one of the super-chargers, but battery technology and charging systems are improving constantly, so we
will without doubt see improving charges times for
newer vehicles.  


The good and the great

In the first in a series of articles, Ian Gillgrass shows how following the diagnostic process can turn a good technician into a great technician
Published:  17 February, 2018

Being part of Top Technician for the last few years, I have seen many technicians succeed and develop new skills. Typically all are good rounded technicians and have great knowledge, but what makes the difference and makes the good into the great?
    
It’s not just that they are lucky. The difference is that a great diagnostic technician will have a well-defined diagnostic process (or procedure) that they stick to every time.

Process
Some technicians start their diagnostic procedure with a well laid-out and defined process that they have normally learnt, often from training courses. As with any new process, it starts slowly as theory is put into practice until it becomes natural.
    
Many technicians typically revert ‘back to type’ during the early stages, as their older method seems to make the diagnostic process shorter. As a result they believe it could make them more money. Yes, in the short term they may be right. However, normally in the longer term a well-defined diagnostic process proves to be infallible especially when the fault is difficult to diagnose or a vehicle that has been to several garages and the fault is still apparent.
    
Many technicians also try to shortcut the process, taking out some of the steps that don’t seem to help in finding the answer. Sometimes a simple fault is made more complex by the technician overlooking the obvious in the second or third step, jumping from step one to step four because that’s where they feel comfortable. In this series of articles I’ll be covering the 10 steps that make up a well-planned, well organised, tried and tested diagnostic process. Use the process and refine it within your business, it works.
    
Many businesses use a similar structured process and base their estimating/costing model on it
as well.

Meaning
Let’s start at the beginning, with the meaning of diagnosis. Most technicians will look at the word and think it only relates to a computer controlled system and they have to use a fault code/scan tool to be able to diagnose a fault. This is not the case. Diagnosis can relate to any fault, whether that is electrical or mechanical. Therefore, the diagnosis can relate to an electronic fault by the malfunction indicator lamp (MIL) indicating a fault exists or a mechanical fault that exists within a clutch operating system.
    
The meaning of diagnosis is: ‘The identification of a fault by the examination of symptoms and signs and by other investigations to enable a conclusion to be reached.’
    
Or alternatively: ‘Through the analysis of facts of the fault, to gain an understanding which leads to
a conclusion.’
    
Both can relate to various professions.
    
With this in mind, what have celebrity chef Paul Hollywood, your doctor, the green keeper at the local golf course and a automotive technician all  got in common?
    
They all use a diagnostic process within their profession. Paul Hollywood is often seen as a judge within baking competitions. He uses his experience and process to perform a diagnosis on why a bread is not cooked correctly.
    
Meanwhile, a doctor uses a diagnostic process to find an illness. A green keeper uses a diagnostic process to determine why the grass does not grow as green as it should, while a automotive technician performs a diagnostic process to find the fault on a vehicle.

Let’s begin to go through the steps of the diagnostic process.

Step 1: Customer questioning

Being able to question the driver of the vehicle of the fault is always a very important part of the diagnostic process. Using a well-structured and documented series of questions can determine how the fault should be approached. Many experienced technicians do this part very well, but when a business becomes bigger, the customer’s information on a fault can get lost  when passed between the receptionist and the workshop.
    
A document can be developed to perform this task, and is often the solution here.
    
A customer has often seen a ‘warning lamp’ on the dash. They can only remember that it was an amber colour and it looked like a steering wheel. The document shown has a variety of warning light symbols that they can simply highlight to let the technician know of the MIL symbol and in the circumstances that the fault occurs (driving uphill around a right-hand bend etc).
    
Much of the diagnostic process is about building a picture before the vehicle is worked on. Trying to fix the fault by jumping to step 4 or step 5 can often neglect what the customer has to say. One of the last steps in the diagnostic process is to confirm that the fault has been correctly repaired and will not occur again (‘first time fix’). How can the fix be successfully tested if the circumstances where  the fault occurred are not replicated during the final stages of the process?
    
The MIL illuminating again (recurring fault) when the vehicle is driven by the customer is not always as easy to fix a second time, as you need to fix the vehicle fault as well as fix the customer, who has been forced to return.

Step 2: Confirm the fault
Some technicians just seem to take the fault highlighted as by the job card (or similar document) and diagnose the fault without first confirming, which can take some time to complete. This step might involve a road test to confirm that the fault exists. The apparent fault may be just a characteristic of the vehicle or the receptionist/customer may have explained the fault to be on the other side of the vehicle.
    
Therefore, it is imperative that the technician confirms that the fault exists and the situation that the
fault exists within, all providing additional information on building
the picture before actually working
on the vehicle.

Step 3: Know the system and its function
In order to fix a vehicle fault(s) a technician will first need to understand how the system works. If a technician doesn’t know how the system works how can they fix it?
    
Don’t be shy or foolish and indicate that a technician knows everything (even on a specific manufacturer brand). Every technician sometimes needs to either carry out new system training or just have a reminder on how a system works.  
    
With all the systems now fitted to a vehicle, it’s not surprising that a technician cannot remember every system and its function especially to a specific vehicle manufacturer or the model within the range. A technician may just need to remind themselves on the system operation or fully research the vehicle system.
    
Most vehicle manufacturers will provide information on how a particular system works and how that system integrates (if applicable) with other systems of the vehicle. Spending some time researching the system can pay dividends in terms of time spent diagnosing the system and it is also educational. System functionality can often be learnt from attending training courses but if these are not available the information can be sourced from various other sources such as websites.
    
External training courses can provide additional benefits especially discovering how a system operates and understanding its functionality and how the various components work. They will also allow the technician to focus on the specific system without the distraction of customers or colleagues.
    
Once the system is thoroughly understood, the technician may be able to make some judgements as which components are ok and those which may be faulty and affect the system operation.

Refine
Just to recap on the three diagnosis steps covered in this article, these were:
Step 1: Customer questioning
Step 2: Confirm the fault
Step 3: Know the system and its function

Remember to follow the process and don’t try to short circuit it. Some steps my take longer to accomplish than others and some may be outside of your control (it may be necessary to educate others). Practice, practice, practice. Refine the process to fit in with your business and its practices, align your estimating/cost model to the process to be able to charge effectively.

Next steps
In the next article I will be looking at the next four steps which are seen to be:
Step 4: Gather evidence    
Step 5: Analyse the evidence
Step 6: Plan the test routine
Step 7: System testing

The last article in this series will indicate the final three steps and how to fit them all together in order to become a great technician and perhaps win Top Technician or Top Garage in 2018. Go to www.toptechnicianonline.co.uk to enter this year’s competition. The first round is open until the end of February 2018.
    
Every entry is anonymous so have a go!


Knowing me, knowing you

Barnaby Donohew asks if by understanding its customers better, a garage can see itself more clearly and provide a better service as a result
Published:  15 February, 2018

Since retirement, I’ve found my Dad reflecting on his time in the motor trade; all the memories, good days, bad days and everything in between.

The one thing he misses is the customers. Not the work, the vehicles, or any other aspects of the business – okay, maybe he misses some of the trade contacts, but this article isn’t about them. We were lucky, we had more than our fair share of fantastic customers, but we also had others that would make your blood boil. And the problem with the latter is that they breed feelings of ambivalence towards customers in general. I’m fairly confident in guessing that you will know what
I mean.
    
Why is it then that a proportion of the people that we deliberately lure towards our businesses provoke these mixed feelings? Well, I think it’s all about expectation. More specifically, the conflicts that arise when there is a difference between what we expect to happen and what actually happens. Some of these conflicts might be avoided by different approaches to communication. Sometimes there are more fundamental issues at stake; maybe the fit between the business and the customer just isn’t right?
    
We’ll return to this idea of fit in a subsequent article as it cuts straight to the heart of our respective business propositions but before we do that, it will help if we understand better both ourselves and our customers. We’ll begin with the troublemakers…
our customers.
    
Is everyone going to be a suitable customer for our business? No, so we need to identify those who could be. For those of us with workshops, it should go without saying that our customers should be vehicle owners (which we’ll loosely take to mean as anyone that has an interest in the successful functioning and care of a vehicle). We can subdivide this group in to private vehicle owners, fleet owners, leasing companies, etc. (note how these groups will have their own more specific interests). Other subgroups might be created using assumed-wealth (poor or rich), make of vehicle (as might be relevant to manufacturer dealerships or independent specialists), or customer and workshop locations (rural or urban) etc. Selecting parameters for such breaking up is never easy; however, once segmented in this way, we are better able to characterise specific customers. On that path lies the understanding
we seek.


Fighting technology with science

Frank goes all-out looking for the cause of a vibration on an otherwise very well maintained car
Published:  13 February, 2018

I am sure all diagnostic technicians out there will agree vehicles are becoming ever more difficult to diagnose. Two obvious reasons include the increase in networked systems, and difficult accessibility.

The first step is to conduct a non-intrusive serial evaluation. This method often provides insufficient information to progress directly to a repair solution. What if the problem is a non-monitored component, or possibly a non-monitored component causing a negative reaction in a monitored component? Sounds confusing, then you will appreciate the following diagnosis and repair review.
Here is a conundrum: What has a vibration at around 100hz got to do with a EGR fault?  

The vehicle in question is a 1.4 16v mk4 Golf 1J chassis. The vehicle history is very well known to us as it was owned by our staff member, Annette. She had it well maintained for many years despite its 125,000 miles.

It had a minor serial error relating to EGR flow. A new OE valve was fitted many years ago without success. The vehicle performed extremely well so we ignored it. The vehicle passed into my ownership several weeks ago. My intention was to prepare it for my partner’s two sons as their first car. Totally new OE brakes front and rear, four new Goodyear 185/65/14 tyres… anyone spotted an anomaly yet?

Rear wheel bearings re-packed with grease, all fluids replaced. New OE exhaust system. The car drives superbly. Brake balance differential 1%! Perfect emissions. I decided to use the car for the Pico NVH-WPS course held during a weekend in November. On the Saturday we conducted several tests to confirm the mechanical efficiency of the engine.

The primary test, following a battery status and health check, was a relative compression test conducted in the Pico diagnostics platform. It’s very quick with only the battery connected to channel 1.

The result was excellent, all cylinders returning a differential of 100%. Let’s digest this for a moment, this does not confirm good compression or correct valve timing. It’s simply a balance of voltage drop whilst cranking the engine. You know what, a bad result here always indicates a serious internal engine problem.

Testing
We then discussed the issue of pumping losses and how this can be addressed with throttle control, variable valve timing and lift, and not forgetting cylinder cancellation! This progressed to dynamic compression tests on the engine using WPS. The results were excellent showing good pressure differential (note I don’t call it vacuum as there is no such thing) suggesting efficient cylinder and
valve seal.

The day ended with a prep talk on the advantages of noise and vibration monitoring. Sunday began discussing the information required for manual data entry into NVH platform. This includes PIDs, notably engine speed via a Mongoose serial interface. All the gearbox and differential ratios were entered together with the tyre sizes. Did you spot the anomaly yet?

Basically, the software can now calculate frequency and speed against noise and vibration signatures across all engine, gear selection, and wheel speeds. Remember frequency HZ x 60 = RPM.

RPM div 60 = HZ. Down the road we went several times sticking weights everywhere to demonstrate different vibration signatures. Due to the quality tyres and general smoothness of the car there was very little vibration to look at.

However, on closer inspection there was a vibration concern around 100 HZ. Apply the maths and you get 6,000 RPM. The engine E1 was around 50HZ! 3,000RPM and there was a E2 vibration, so whatever it was had to be  engine  ancillary related. Further inspection using a roaming microphone to pin point the noise confirmed a very noisy serpentine belt idle pulley bearing. This is where the shock on my part and the realisation of the incredible value of applying science and physics to an everyday problem pays off. I decided to conduct the repair myself the next day, stripping the front end exposed a fractured timing belt guide and badly impregnated timing belt tension pulley. The broken half of the guide was hovering inside the timing cover I guess just waiting to do its worst!

Pic pulleys
Several pulleys were singing like canaries despite no previous and obvious audible noises. So, three hours later and a total front end rebuild with OE parts, including water pump, we have an even sweeter engine. So, what else did I find? My original training was as a precision engineer specifically in engine remanufacture so instinctively I don’t strip out timing assemblies until I have checked the original position. It was one tooth out on the crankshaft!

Humming, I think timing out, manifold pressure will change, it’s a MAP sensed load system, so EGR is calculated from an algorithm based on throttle, map value and EGR control ratio, with feedback.

Eventually we discover the historical problem of a seemingly innocuous EGR DTC. In conclusion by recording vibration from the driver’s seat frame, yes, I do mean from inside the car,
we pin point a potentially engine critical fault.

A mechanical non-monitored component affecting a monitored sensor value! One last thought – the anomaly! The standard tyre specification for a Golf 1.4 1J IS 185/80/14. I deliberately wanted more responsive high-end tyres. The speedo is almost 10mph out, not a bad idea for two 24/25-year olds.

Want to know more?
If you want to get on the NVH bandwagon, email Annette @ads-global.co.uk or call 01772 201597.


Fig. 2

New Year – Fresh perspective

Published:  29 January, 2018

Into 2018, John looks at the steps you need to take to make your workshop more efficient, while obeying the Laws of Diagnostics


technologies of electric and hybrid vehicles

Part two: In the second part of his look into EV and hybrid technology Peter of Tech-Club examines the functional specifics of electric vehicles
Published:  16 January, 2018

In the first article in this series, published in the November issue, we looked at some of the issues relating to the batteries used in electric and hybrid vehicles. As brief summary: Modern lithium based batteries typically store four times more energy than a traditional lead-acid battery of the same weight.  


Aftermarket scenario planning

Barnaby looks at the various trends influencing the development of the sector and asks what they might tell us about our future
Published:  13 December, 2017

Definition of uncertainty:
a state of having limited knowledge where it is impossible to exactly describe the existing state, a future outcome, or more than one possible outcome.


Putting pressure on a Polo

Frank explains how there can be more to a misfire than you think
Published:  07 December, 2017

I have always tried to express the importance of logic and process in any diagnostic challenge. Added to this foundation training principle should be common sense and simplicity.


Small Steps = BIG Results

John Batten gets philosophical talking systems, processes and the potential of ‘desk diagnostics’ to change a businesses for the better
Published:  01 December, 2017

There’s no doubt about it-  the technical challenges that face an independent workshop grow daily and this has the ability to not only affect the commercial performance of the business but also the morale of those at the sharp end.


Plain sailing

John Batten examines the course you need to follow to enter the seas of perpetual success
Published:  21 November, 2017

I'm not the nautical type, but I know that setting sail without sufficient preparation is foolhardy and the likelihood of you reaching your destination in a timely manner, at an agreeable cost with a healthy profit margin would be highly unlikely.
Why then do we set off into ‘technical repairs’ without preparation, but remain surprised when we meander into fog, or ends up on the rocks... No I'm not sure why either.

Elements for success
How do we avoid the perils? It's quite straightforward. The amazing thing is that the components for a smooth journey can be applied to any repair regardless of vehicle or system. So what do you need?
 


technologies of electric and hybrid vehicles

Peter Coombes of Tech-Club looks at how the benefits and challenges of battery technology define electric vehicles, and shape your future
Published:  13 November, 2017

Having recently presented short seminars about electric vehicle technology at Top Tech Live, and at some other trade events, it has become clear that technicians are only slowly beginning to delve into the
world of electric and hybrid vehicle technologies.   


Rue de Qualite

Frank Massey takes a tour that provides clarity on the issue of name brand parts over pattern alternatives
Published:  07 November, 2017

This month I have chosen a subject from a recent visit to NTN SNR at their Annecy plants in the Rhone alps region of France.
Last week found me at Lyon airport, thankfully not with Ryanair. There are seven plants, if my memory serves me correctly. It is a proud French company with global facilities in the far east, central Europe and the Americas. Their adopted company language is English- so much for Brexit and ill feelings. Take it from me it does not exist, except in the minds of the idiots we call politicians.
The company produces a huge range of bearings for a cross section of transport segments such as light vehicle and public transport. This includes the incredible demands of the TGV, commercial vehicles, and earth moving plant and aerospace such as Airbus and others.

This subject I hope, brings some reality into what is often expressed as an emotive opinion without substance or fact-based evidence.


Immobilisers and (in)security

Barnaby Donohew asks if increasingly complex vehicle security systems are an opportunity or a risk
Published:  24 October, 2017

We need to talk about security. Why? Because deliberately or not, its effects are mutating our opportunities within the automotive aftermarket. We need to understand more about it and, at some point, to try to anticipate the eventual set of circumstances to which it might lead. As they say, forewarned is forearmed.

We’ll begin by looking at an example of a recent security system and checking out its inner workings. We’ll review its potential vulnerabilities and assess the need for, and impacts of, increased security. First though, we’ll cover some general concepts, to keep in our minds the bigger picture regarding possible motivations for increased security.


Security
Security is the protection of things having value, where they might be at risk from theft or attack; i.e. when they have, or are perceived to have a vulnerability. Security aims to prevent an agent of ill-intent (e.g. criminals, intruders, missiles, or computer-viruses etc.) from gaining access. The consequence of this is the introduction of barriers to those requiring legitimate access, such as owners, occupiers, citizens or data-holders. This dichotomy is at the heart of all security implementation issues. This always begs the question; what level of security balances an intended degree of protection from risk, with the subsequent barriers to legitimate access or freedoms?

As the assessment of risk primarily determines the necessary level of security, it is not hard to imagine that superficially legitimate security concerns can be used to justify limiting access to a favoured group. It’s a simple trick, just inflate the perceived risks and exaggerate the vulnerabilities where necessary. A similar mechanism can be used in a health and safety environment, where legitimate but undesirable behaviours in the eyes of the decision makers can be quashed by deliberate overstatement of the perceived risks. When loaded with the weight of moral absolutes (“lives are at stake”), the arguments seem powerful but are they really intended to shut-down reasoned debate regarding the actual risks? Anyway, the point is, we cannot have a reasonable discussion regarding proportionate levels of security without being able to properly assess potential vulnerabilities and associated risks.


Immobilisation
Vehicle immobiliser systems have been developed to protect vehicles from theft. There is a clear need for the security as the risks are very real. Car thefts were far more common prior to their development. Such systems work by only allowing vehicle mobilisation when a key, placed in the ignition switch, is from the unique set authorised to start the vehicle. The following describes a representative immobiliser system and its behaviour during ignition-on and engine-start conditions, just after the car has been unlocked. As we will be discussing potential vulnerabilities, the make and model is not given.

Component-wise, such systems usually consist of a transponder in the key head, a transponder coil around the ignition switch and an immobilisation control system within either a dedicated immobiliser control module, or another control unit, such as the central electronics module (CEM). The CEM might be hard-wired to an immobiliser indicator in the dashboard or instrument cluster (IC), to indicate the system’s status to the user. The CEM will communicate with the engine control module (ECM) using a CAN bus. Note that, if the CEM is on the medium-speed CAN bus and the ECM on the high-speed CAN bus, then a control module that is connected to both buses, such as the IC, will need to act as a gateway to communications between the two.

There are usually two stages to the authorisation/start process; the first, a key checking phase, is initiated when the key is placed in the ignition barrel and the second is a start-authorisation phase, instigated when the operator turns on the ignition.
A typical key checking phase might progress as follows (see Figure 1 for the representative signals): initially the system will be in an immobilised state, indicated by periodic flashing (e.g. once every two seconds) of the immobiliser indicator. When the key is placed in the ignition switch, the CEM energises the transponder coil (e.g. at 125 kHz), which excites the transponder. The transponder responds by transmitting identification and rolling code data to the CEM via an inductive voltage within the transponder coil circuit. The CEM will check the returned data against the stored data to confirm its identity. The CEM might double-check the key identity using the same mechanism.

The start-authorisation phase proceeds as follows: When the ignition key is turned to position II (ignition on), the ECM detects the ignition supply voltage and sends a start request CAN message to the CEM. If the key is valid, the CEM responds positively, with a code derived from the message contents sent by the ECM. In return, the ECM replies to confirm that the vehicle is in a mobilised state and that it can crank and run the engine. Upon receipt of this confirmation message, the CEM can illuminate the immobiliser indicator (e.g. with a one second confirmation flash) and then turn it off. If the key is invalid, the CEM will respond negatively to the ECM’s start request message, such that the ECM will not crank or start the engine, and the alarm indicator will continue to indicate an immobilised state.


Insecurity
The immobiliser’s subsystems could be vulnerable to several types of attack: Key recognition; The key recognition subsystem, consisting of the CEM, transponder coil or and transponder, could be prone to attack if the correct rolling codes could be transmitted in the right way and at the right time. Note that to move the vehicle, the correct mechanical key would need to be in place to remove steering locks etc. Key-less start systems present other sequencing issues (related to direct CAN messaging, described below), which would need to be co-ordinated with the press of the engine start button etc. The biggest vulnerability and simplest way to attack the system is to clone an authorised key.

Direct access to the CAN bus; If the start-request from the ECM and subsequent immobiliser related messages can be intercepted and the appropriate (algorithmically generated) response codes returned, then the CAN communication system could be used to carry out unauthorised mobilisation of a vehicle. The method would rely on a controllable communication device having a physical connection with the CAN bus. Timing is important (the messages are often expected to be received within a certain time frame) and the genuine responses that would be sent out by the immobiliser controller would need to be mitigated against (e.g. the filtering out of its likely negative response to a start request, that might cause the ECM to immobilise itself).

Aside from the practical connectivity and the sequencing issues, there is the issue of knowing how to generate the correct response codes to a start request. Although, the codes are observable in an unencrypted network, the relationship between the in and out codes can be extremely difficult to calculate using analytic methods alone and are more likely to be determined from reverse engineering of the control unit’s program files. Aside from the legal implications, the challenge is still great, which is very likely why it has not appeared to have happened.

Indirect access to the CAN bus; Given the potential difficulties of physically placing a communication device on the CAN bus, an alternative approach is to hijack a device that is already connected. Any internal (software or hardware) system within a connected control module that has access to the controller’s CAN interface might provide a channel through which unauthorised access could be attempted (especially if a vehicle manufacturer has already built-in a remote starting capability).

It is this type of attack that has been highlighted as a particular concern with the advent of connected vehicles, purportedly presenting hackers with opportunity to remotely control some or all of a vehicle’s functionality. There have been notably few examples of vehicles being hacked in this way and it will be very interesting to see if that changes over the coming years.
All in all, the challenges needing to be overcome to take advantage of any the three perceived vulnerabilities and to steal a car are great. Quite simply the easiest form of attack is to clone a key. The question is then, what are the motivations for ill-intentioned agents to attack our automobiles and are they likely to want to try to steal a car through attacking the immobiliser system? I’m not sure I’m qualified to answer that.


Information
There is a further, related, development that has already dawned within our automotive landscape. Our modern motor vehicles are capable of generating significant volumes of personal data regarding much of our travel and lifestyle habits. This information is hugely valuable. Google’s company worth is colossal and their value is driven purely by their knowledge of our online browsing habits (through the use of their web applications). For the most part, we are not always online. Imagine though, if they could collect a raw feed of data regarding our offline habits, such as those we might create when we travel within our vehicles. How much would the company that had access to that data be worth? With that thought, it is clear why tech firms are falling over themselves to tap into our automotive existences.

Given that all this valuable data is flying around unencrypted vehicle communication networks (much of it is required by engine, navigation, entertainment and ADAS systems etc.), why in their right minds, would the vehicle manufacturers not want to encrypt that data and keep it to themselves? By doing so they would be able to prevent any third parties, including (coincidentally) aftermarket diagnostic tool manufacturers, from having any access to a vehicle’s CAN bus data, without the vehicle manufacturer’s prior consent.

Now, in that context, wouldn’t it be convenient if the vehicle manufacturers jumped upon the reports of the hackers’ abilities to put lives at risk, so as to justify the encryption of vehicle networks? Conspiracy theory? Maybe. I am susceptible. I once imagined that the large discrepancy between real-world and quoted fuel efficiency figures could have been indicative of an OE-level distortion of engine test results…


Further tech info
http://automotiveanalytics.net/agile-diagnostics




Dirty work: Keeping diesel exhausts clean

Diesel vehicle exhaust systems can run clean if they are given the proper care, and vital components like the DPF are properly serviced
Published:  11 October, 2017

The exhaust is a lot more than just an exit route for waste gases for some time now. Tim Howes, deputy general manager – supply chain and technical service, NGK Spark Plugs (UK) Ltd, provides some context: “In 2009, The Euro V emissions standard for passenger cars demanded a significant reduction in NOx, HC and particulate matter and in 2014 the Euro VI standard brought a further tightening of these emissions, primarily for diesel engines.”


Complexity
For diesel powered vehicles this has meant a significant increase in the complexity of exhaust gas recirculation (EGR) and after treatment resulting in the fitment of various combinations of diesel oxidising catalyst (DOC), selective catalytic reduction (SCR), lean NOx trap (LNT),  diesel particulate filter (DPF) and other associated devices and control systems.
All these additional components have led to an increased need for sensors in the system.


Spin the wheel

Frank Massey looks at how you need to approach a problem when different types of sensor are involved
Published:  09 October, 2017

I have been asked several times about ABS wheel sensors. Like many other components, the technology is changing. The changes reflect the expansion in integrated chassis dynamics.

Just imagine how many functions require wheel speed and rotational differential data.

ABS, dynamic stability, hill start, audio volume, navigation, self park, all wheel drive, active steering assist, electronic handbrake etc. Sharing this data on a high speed can network ensures very accurate vehicle motion dynamics.

Older variable reluctance sensors (VRS) rely on a coil generating an alternating voltage when rotation occurs. The problem is they are not directional sensitive and cannot report motion at very low speed. Air gaps were critical as they affect signal amplitude. They are often referred to as passive sensors. So, the introduction of digital or active sensors was inevitable.


Principles
How do we tell them apart? Active sensors require a voltage supply from the ABS PCM, with a ground or signal return. They operate with different principles of signal generation; hall, and magneto resistive. Pure hall effect sensors will switch between the supply potential voltage and ground. Magneto resistive sensors operate on the principle of current and voltage change in response to a change in magnetic induction. This change can be introduced in several ways reflected in wheel bearing and sensor design. Smaller sensors with integrated magnetic field rings are now the norm. Developed by NTN at their Annecy facility they are called encoded bearings. A small ring mounted at one end of the bearing carries a series of north south poles. These have now been replaced by dual encoding, two sets of magnetic rings with a unique offset. This enables the abs module to determine direction of rotation.


Subtle differences
There are two very subtle differences in the digital outputs. They can be called pull up or pull down. The sensor supply voltage will be slightly lower than battery voltage this is due to the different internal resistance values. However, it will be around 10.5/11.5v.

The ground or return signal value will vary between 0v or 1.4/1.8v. You could have a sensor or circuit fault; let me try and explain the subtle differences, and how to prove which is which. Remember the golden rule if in doubt compare a wheel circuit that works normally.

First unplug the sensor and measure both circuits in the loom. With no load applied the supply voltage should jump up to NBV

Next check the ground circuit if its true ground then it’s a pull-down type and the signal will be on the power line, and may only be around 200mv

If a small voltage exists then it’s a pull up type and the signal will be on this wire not the supply. The digital signal will be very small when the wheel rotates. It could be small around 200/400mv, or as high as 0.5/1.8v, depending on the manufacturer variant

Common sense would dictate the serial route is easiest, however how would you determine an intermittent fault? It could be a faulty sensor, faulty encoder, or a circuit error. The only way is using a scope. Should we measure voltage or current though? Both change in the circuit. Unless you have a very special current clamp, go for voltage and select a AC coupling.

The specific question I am often asked is current measurement, well I can tell you in a pull-down circuit its around 7-15 ma with a 400mv voltage change. The pull up type will produce around 6/13ma with 0.2/0.35mv.     However, these voltage values can vary due to the value of the two parallel internal sensor resistors these are normally 1.4k ohms, with a much higher resistor in the meg ohm range, within the ABS pcm.

I hope this helps. The pico image was taken from a VW Golf 1.4 TSI. The easy bit is replacing the wheel sensors. Ever since metal housings were replaced with plastic they never corrode in the housings
do they…?


Electric future shock

Here we take look at the many challenges the independent garage sectors faces in an increasingly electric future
Published:  05 October, 2017

The need to adapt to changing vehicle technology is one of the main challenges of our time in the sector. Increasing connectivity and a vastly more complicated conventional vehicle provide a whole raft of obstacles on their own, before you even get to the rise of electric vehicles and hybrids.

Add to that a more uncertain legislative environment resulting from rules not quite keeping up with the technology coming in, and you’ve got yourself a whole host of issues that the entire industry needs to stay on top of if it is going to continue to offer a sterling service to customers.

Let’s look at electric vehicles. For Tom Harrison Lord from Fox Agency, the b2b marketing company specialising in the automotive sector,  Automechanika Birmingham offered a troubling glimpse into the future:  “This summer’s Automechanika Birmingham was entertaining and enjoyable as ever, but it also exemplified a worrying trend in the motor industry today. With the advancement of electric vehicles, there are going to be some rapid and stark changes ahead. The automotive aftermarket, however, seems to be burying its head in the sand.”


Access
The key, as it has been in the past, is access. In this case, the right to be able to repair vehicles. Think that’s all sorted? Perhaps not:  “The rise of the electric cars and vehicles is something that could hit the automotive aftermarket hard – in particular, independent garages.

“Many, if not all, electric vehicles invalidate their manufacturer warranty if essential work is carried out on the electrical systems by someone other than the main dealer. What’s more, many cars with batteries, such as the Mitsubishi Outlander PHEV, have warranties on the electrical components lasting up to ten years.

“Having no choice but to use the main dealer for a full decade shows just why independent workshops will have fewer vehicles coming through the doors in the years ahead.”


Fighting through to a solution

Published:  20 September, 2017

Do our own workshop war stories point to a diagnostic way forward asks  James Dillon


Agile Diagnostics

Published:  17 September, 2017

Barnaby Donohew examines how the aftermarket can learn from the tech sector to improve diagnostic outcome


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