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Reprogramming today's vehicles and Old Murphy

Avoiding the failed programming event when diagnosing today’s vehicle complaints.
Wednesday, June 25, 2014 - 07:00
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Have you ever noticed how time itself seems to have a large influence on one’s misfortune? What I mean is, it seems as if the probability of something unusual happening is directly and inversely proportional to the amount of free time you’ve allowed for a particular task. The less free time, the more likely something will go wrong. In addition, the severity of complications has the same inverse relationship to time. The less free time, the worse the complication becomes. Can you relate?

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One of Murphy’s Laws says, “If something can go wrong, it will, and at the wrong time.” It seems like no matter what you do to prevent anything from going wrong, something still goes wrong. If whatever it is that goes wrong happens while you’re attempting to program an Electronic Control Unit (ECU), then it’s entirely possible you won’t be very happy either. I’ll outline in this article the procedures I follow before, during and after programming, most of which are done to prevent something from going wrong in the process. I’ll also present one technique I use to remedy the situation(s) when things do go awry.

Only a few strands remained intact on the PCM ignition feed wire.

In addition to being a technical article contributor, I also am a mobile automotive diagnostic technician; one who travels from shop to shop helping them diagnose problem vehicles. I have a service area that is larger than the state of Rhode Island, therefore it is very important for me to diagnose efficiently. I’d better be well organized in order to fulfill my promises, because I might have many shops scheduled to visit in one day.

Don’t you have similar needs (excluding travelling, that is)? Don’t you have to diagnose vehicle problems efficiently in order to fulfill the rest of your scheduled jobs? The problem is we can’t always know how long it will take to determine the cause of a customer’s complaint ahead of time. Coining a phrase that my buddy Sam might say, “We don’t know what we don’t know,” so we can’t always accurately estimate how long it will take to come to the conclusion of what’s causing the problem.

In all cases there is a certain amount of work that should be done to determine the causes of the previously unknown culprit (some call them gremlins). I ask my customers to do as much of the diagnostics they can themselves, whatever they are comfortable with, before enlisting my services. I prefer to not be the one actually diagnosing a vehicle, so in most cases I’ll work with my customers (mostly the technicians) over the phone to help them confirm their findings prior to lending a physical presence if it’s needed. Sometimes they aren’t familiar with the vehicle or the system they’re working on. Sometimes they lack the confidence in their tools or in their own abilities or sometimes they just want to “bounce something off” another person who may have a different perspective.

With the inner fender removed for service, the harness support was lost and the broken wiring strands were no longer contacting one another, leaving just the few to carry the current load.

I define diagnostics as the process of elimination. We verify what’s working correctly and eliminate those as causes of what’s not right. Some diagnostic routines used to include the statement “install a known-good part.” Most professional technicians and shop owners have found the “part substitution” method of diagnostics just doesn’t work these days and even might cause more problems than the vehicle originally came in with. Also, it’s gotten expensive condemning a part in modern vehicles.

Some of the expense can be calculated in non-billable labor hours because installing parts to see if the problem’s solved might be wasted time. Therefore, one must be sure a replacement part will solve the problem before ordering it. In addition, part substitution is not what I call diagnosing; it’s guessing.

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