A problem with referrals

A referred Audi A4 makes its way into James' workshop

Published:  12 March, 2015

By James Dillon

As a diagnostic specialist business, we are often asked to look at vehicles which have had previous repair attempts made. Sometimes the customers find us by themselves, as they may be frustrated with the performance of the previous repairer or, the other repairer may choose to engage our services directly when they have run out of steam with a job.

Non-referred jobs can often present their own set of issues. The frustrated customer usually requires some form of booking-in 'therapy'. The customer, understandably, is very keen to find out exactly how much we will charge them and, very early in their conversation, they tell us how much they've spent at the other place trying to get the fault sorted and how they have not got much money left to spend fixing the problem. I'm sure many reading this piece have experienced similar things.

The focus of this article is on an Audi A4 which appeared at my workshop having had a new convenience ECU put in. The garage that fitted and coded the convenience ECU wasn't the garage that diagnosed it. Worryingly, and this probably should have set the alarm bells ringing, the garage that diagnosed the ECU as being faulty, didn't have the capability to code the new ECU to the car (a simple variant coding procedure and remote key fob matching which most aftermarket scan tools will do). I was wondering about their capability to make a correct diagnosis in light of this. As the convenience ECU is a pattern failure part (typically due to water ingress), usually resulting in a distinct set of symptoms, I considered that they may have used the 'prior knowledge' diagnostic route, in other words chancing it and taking a punt based on probability.

Figure 1

Figure 2

Figure 4

I discussed my findings with the customer and they authorised the purchase of a new central electrics ECU. It arrived the next morning and once fitted the symptoms were fixed. A quick check of the CAN signals showed all was well electrically. The failed ECU was indeed the root cause of the problem. The customer was delighted to have the vehicle back in full working order.

I thought that I'd support this case study with a video, so I chose to record my diagnostic journey with this vehicle. It is unscripted, off the cuff and sort of unfolds as I do the repair; therefore, it's not cinematographically perfect. However, it does provide an insight into the diagnostics processes of this case study. The video can be found on the YouTube Channel 'dillondiagnostics'.

FIGURE 2:?Global scan reveals faults

FIGURE 4:?With the central electrics ECU unplugged, a perfect waveform


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