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lou's garage

I was reading your column regarding the fellow who waited so long to get his 2021 Nissan Sentra back from the dealer, and I’m wondering what gives, especially your comment regarding swapping parts until you find the problem.

I’ve worked on cars (and electronics) for many years, although I’m not a professional, and I’ve always found the part needing replacement, and replaced that. And I’m not talking changing brakes and stuff, I’m talking rebuilding transmissions, rebuilding engines, repairing electronic faults in modules and valve bodies, in hundreds of vehicles.

While it seems to me that many modern cars have ridiculously complex electronics to control very mundane features, technicians should still be able to locate faults by ordinary troubleshooting, not by swapping parts until the problem is found. A number of friends have complained of the cost of several replacement parts on their vehicles, often with problems still not rectified.

Are we training people to just swap parts or are we teaching them how systems work and how to troubleshoot? I started out as an electronics tech when we troubleshooted down to individual components and left when it was just replacing entire boards or modules.

Anecdotally, it seems that when something new or unexpected comes up, outside the typical repairs done day in and day out, many techs are baffled because they don’t know how to fault-find. Or is it just not profitable to spend the time required? - Nathaniel P.

Back in the 1990s and early 2000s as a dealer technician we used thick paper manuals and were required to follow diagnostic flow charts when performing any electrical diagnosis. Vehicle electronic complexity was exploding forcing technicians to expand their horizons and adopt new thoughts and processes. When a module or complex electrical component was suspect, the testing of that specific part was a challenge considering the time period. Computerized factory scan tool abilities were limited, being in their product development infancy and not robust enough to be able to test the internal workings of many of these components.

The flow charts we used tested everything around the suspect electronic component ensuring that adequate voltage was being supplied and controlling switches and sensors were also functioning properly. Because there was sometimes no specific test for the unit in question, the flow chart made sure everything else was working, thus leading to a process-of-elimination conclusion worded with something like this – replace the suspect part with a known good unit and retest. What that means is that if everything else was working but a problem was still present you had to substitute in another part that you knew was good.

If a technician was diagnosing a car that was still covered by the manufacturer’s warranty, once you demonstrated adequately that you had followed the flow chart to its completion, the manufacturer would send you a new part for the retest. This process continued until the vehicle was fixed. When the car was covered under warranty, this procedure happened behind the scenes with the cost being borne by the manufacturer. Alternatively, when a vehicle was out of warranty the dealer service advisors job became exceptionally more difficult as they now had to explain this process and all costs that came along with it. Costs that were ultimately being passed on to the customer.

Quite often I witnessed other technicians and myself being instructed by management to fetch a similar model unsold used car from the used car lot attached to the dealership and to swap parts from it until the problem was isolated. This typically occurred when a customer was really upset, and a solution was needed with controlled costs. And that was 25 years ago.

Current generation diagnostic tools are obviously advanced and with high-speed internet, specially trained manufacturer technicians can assist from the other side of the world. They can be remotely connected to the car, guiding the dealer technician with complex diagnosis. While these new diagnostic tools and procedures may make my time at the dealer look like I was operating in the stone age, we all know that contemporary vehicles are much more complicated. Unfortunately, this creates the same requirement for automotive technicians to absorb and digest information that changes and grows with every new model year.

Thus, from time to time an answer cannot be absolutely guaranteed because of this complexity. There may no longer be paper flow charts and things may be referred to by a different name, but it can come down to the same old procedure known as, substitute in a known good part and retest.

So, are we training staff to be parts swappers? The answer - in some cases is yes.

When you consider your newer cell phone, flat screen TV or any complicated piece of electronics that needs repair, you are often just given another replacement unit if it is still under warranty. That is because labour costs to diagnose most newer electronics usually exceeds the value of the actual component. That is assuming that there is even a known diagnostic procedure.

Lou Trottier is owner-operator of All About Imports in Mississauga. Have a question about maintenance and repair? E-mail globedrive@globeandmail.com, placing “Lou’s Garage” in the subject line.

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