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).


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  • Part two The good and THE GREAT  

    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.



  • Recruitment: What to do about it?  

    This year’s crop of year 11s will be winding up towards their GCSEs over the next couple of months. From there some will opt for the academic route and head onto A-Levels and beyond, while others will be looking to apprenticeships. It must then be time garages to start looking for some new staff to train up?

    Well, probably not – we have already lost out on the 2018 school leavers. No, really. If we wanted to attract them we should have been talking to them and their parents during 2014, or perhaps even earlier, perhaps when they were still at primary school in 2012. Because we didn’t do that, they are going to choose another industry. There’s a host of reasons why, but what do we do about it?

    Things are going to get better?
    “The automotive sector does face a long-standing skills shortage, which is likely to worsen with the developments in new technology,” says Steve Nash, chief executive at the Institute of the Motor Industry.  “New government statistics have shown a
    15% drop in automotive apprenticeship starts, however we haven’t fared too badly compared to the overall 61%.”

    Considering what the industry as a whole has to offer, you’d think young people would be flooding in: “The motor industry has over 250 different job roles that can offer young people a life-long career,” says Steve, “whether that’s in a technician role or management, designer or marketing. Businesses in the motor industry are a shining example of what can be provided through quality training and apprenticeships. We’ve had plenty of practise in providing these training programmes that have allowed us to grow to be one of the largest sectors operating in the UK. Businesses in the automotive industry are certainly well-rehearsed when it comes to adapting to any new changes that are introduced, whether that’s the Levy or Standards that have recently been implemented.”     

    Young people are not going to come our way if they don’t know that however: “The government has removed nearly all careers advice available in schools around the UK,” Steve points out, “and this is having a huge impact on young people. The IMI surveyed parents and young people to find that over 80% of parents said they would choose the university route over an apprenticeship for their children, so it’s clear that transforming apprenticeships alone isn’t enough to breakdown the stigmas associated with vocational learning.

    “Government are continuously reviewing the apprenticeship model, and automotive businesses like Rolls-Royce remain at the heart of these changes. It’s important we’re doing our upmost to transform apprenticeships, and the IMI are confident that the dedication shown by businesses will help attract more young people.”

    So what about technician licensing? It’s already on its way to being reality in one corner of our industry: “The IMI is currently lobbying for a Licence to Practise for vehicle technicians working on electric and hybrid vehicles. Without regulation and a minimum training standard, there are significant safety risks for technicians who may not have any form of training before coming into contact with high-voltage vehicles.

    “The motor industry deserves recognition for their individual training and skills when it comes to working on such advanced technology. The licensing scheme would provide that credibility, as well as offering other benefits to the individual technician who are trained and qualified to work on low-emission vehicles. Benefits include the fact that businesses would be keen to recruit them in order to allow the business to service and maintain these vehicles, and as we’ve seen lately that the appetite for electric and hybrid vehicles shows no sign of slowing down considering their has been as increase of 35%
    this year. Businesses must make the investment in training their staff in order to provide them with the skillset that’ll allow them to service customers who own high-voltage vehicles.”

    Grow your own
    Is licensing the magic potion that will fix all our problems? Industry consultant Andy Savva isn’t so sure: "I'm all for some kind of licensing, but it has to have meat on the bones, not be just some kind of tick-box exercise. Even if we went down that route, I don't think it would have any significance at all on recruitment. This has been an issue for a few years now.

    "We have quite a few problems as an industry. Firstly, the push towards university-based futures from 10-15 years ago took almost all of the young talent away. At the same time there was a lack of decent apprenticeships so there were even less young people contemplating a career in automotive, specifically in the garage repair sector. Coupled to that is the lack of upward mobility for those dynamic young people who want to progress and not just stay on the tools or the front desk. Thirdly we pay very low as an industry compared with other sectors.”  

    Do we need to think bigger?

    “If we don’t raise the status of our industry collectively, then how are we going to recruit the next generation of people regardless what side of the fence you’re sitting," observes Andy.  “In Germany you can't own or manage a garage unless you have completed a three-year degree in Automotive Engineering, which combines business modules too. People in these roles are held in
    the same esteem as solicitors and accountants.”

    Outside of the lack of careers advice, those working in our educational institutions tend to have a very narrow view of the industry that does not help says Andy: "When I speak at schools and colleges, and I get given a group of youngsters, the teacher usually says something like 'these are the kids that are not going to go to university we thought the motor trade may suit them.’ It's not like that now, it's men in white coats. There is probably more computer power in a car now than in most general offices, but people don't look at it like that.

    “The outside world seems to think that if you are not academically minded, and there is nothing wrong with that, then the motor industry is fine for you. They are given the impression that it is low skilled career, but it is far from that.”
    Once someone is in the sector, they are not always handled well either: "At the moment, collectively we have disregarded proper recruitment strategy. How many garage owners understand where recruitment starts from? How do we recruit? Most of them will do the same thing. They will put an ad in the paper or go through a recruitment agency. Now I have nothing against recruiters and there are a handful around the country that offer a wider set of services. I’ve seen at first hand how they are trying to engage with young people at an early stage through a variety of ways up and down the country and I applaud them for this.

    “On remuneration, most garage owners will then pay the same as everyone else because it is the going rate, or even cap technician salaries regardless of skill, age and knowledge. This attitude limits the pool of people who can attract and usually means a whirlwind of the same people going around for a few hundred quid extra or a couple of hours off during the week.”
    Andy adds: “We need to be going into schools at an early age, as a collective automotive sector. It's about growing your own and taking on apprentices and nurturing talent and having a proper personal development plan for each individual and providing proper clean facilities with the correct tooling to enable these youngsters to blossom.”

    All or nothing
    Glen Shepherd, co-founder at automotive recruitment specialists Glen Callum Associates also thinks technician licensing might help with recruitment, but agrees it would not be the end of the story: “Technician licencing may fulfil the wants of the younger generation by allowing them a career option of a ‘professionally skilled job, recognised nationally with continued professional development and training’, however I believe the key to ensuring awareness of the offering to entry level generations would be wholly determined by the promotion of the licencing scheme.   

    “Having attended many recruitment seminars on ‘attracting the millennial and Gen Y generations’ the consensus of opinion is that younger people are on the whole attracted to careers that offer personal development, training, transparency of duties and ‘an employer that holds and demonstrates good values and ethics.’  Licencing, if promoted correctly via schools, colleges and through successful marketing could aid recruitment from emerging generations into the aftermarket.”

    How does this help the skill shortage and awareness of those generations already rooted within the workforce though? “The image of the aftermarket doesn’t mirror the actual modernisation that the sector has undertaken. So, how do we address image and increase awareness of the aftermarket offering?  My view is to inject new blood into the industry, not necessarily at entry level, but by reaching out to talent within comparable industries that carry similarities such as the industrial and engineering sectors. Introducing the outside world into what the sector has to offer and thereby expanding and utilising skills from other sectors.   

    “Companies are trying to employ from a reducing talent pool of traditionally skilled staff, thus pushing up current salaries and increasing demand. By opening out to new skill sets, albeit within periphery sectors, allows increased awareness of the aftermarket, the introduction of new ideals and ideas and a wider pool of skilled staff from which to engage.  

    “We can do this by educating companies within the aftermarket who have historically only recruited within the sector to help broaden their expectations and to promote the benefits of working within the industry. Do we need ‘technician licencing’ to be able to do this?  I think not, however all a positive initiatives promoting recognition of the professionalism within the sector is surely helpful.”

    Don’t stop what you’re doing
    How the industry is viewed is a key issue clearly: “The perception of the motor industry by those outside it creates an image problem that exacerbates many of the issues facing independent garages today and the skills shortage is just one of these” says Terry Gibson, head of member services at the Independent Garage Association (IGA). “However, whilst attracting young people into the industry will solve the problem in the longer term, there is also a need to upskill those already in the industry. This is not limited to hybrid and other new technologies, we face an equal problem in replacing retiring MOT testers where there is an equally pressing need.”

    The IGA is working towards helping widen the net: “The IGA is working with the Armed Forces to consider how best to address the particular need for MOT testers by helping to retrain skilled and experienced military vehicle fitters to aid in their transition to civilian life and this will work alongside an initiative with a major recruitment company.”

    While careers advice in schools has been found wanting as we have seen, Terry believes the industry itself is going in the right direction promoting the importance of training and development, so at least existing staff in the sector continue to upskill: “The messages spread by trade bodies and by the specialist trade press focuses heavily on training and development and this article is a good example of that. The opening of the RMI’s Academies of Automotive Skills shows that the industry is promoting training and development for existing technicians.

    On licensing, Terry observes: “While blanket licensing might, over  time raise the perception of the technician role,  we do not believe it would be a major influencing factor in deciding on an automotive career for young people today – although in the absence of such licensing anywhere in our industry makes it difficult to predict its effects.”

    Terry adds: “We must continue to stress the high-tech nature of modern motor vehicles and ensure that the industry is presented in the best light to those outside. To that end the IGA is working with television producers to ensure that the portrayal of the garage trade in popular drama is realistic and representative.”




  • Reasoning and diagnostics Part II 

    We began this journey last issue, so to recap: We need solid reasoning skills to carry out effective diagnostics; persistently good decision making doesn't happen by chance. Possibly out of convenience these skills are often underestimated and undervalued by people, both in and out of the trade. We must raise awareness of the discipline and precision of thought necessary for logical and critical thinking: so we can be better rewarded for our efforts; and to make sure they are consistently and properly applied.

    Reasoning, arguments and hypotheses
    We covered some fundamentals in my last article: we explain our reasoning using arguments, which contain statements supporting a conclusion; one type of argument, a deductive argument, should guarantee the truth of its conclusion (if it is sound); however, we need to use critical-thinking to check this, by making sure i) there are no other possible conclusions (which makes it a valid argument) and ii) the supporting statements are true.

  • IMI report highlights case for technician licensing  

    The Institute of the Motor Industry (IMI), has presented MPs and peers from the House of Lords with a new report that underlines the case for regulation around those working on electric and hybrid vehicles.

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