Often times, I have wondered who coined the phrase “silver bullets” as it applies to the automotive service and repair industry. Unless of course the malfunctioning vehicle was to be considered a werewolf! But there is no doubt that knowing what is causing a malfunction and its remedy before the job comes into the shop is welcomed information. When you experience a silver bullet fix, you think to yourself, “It sure would be nice if I had a silver bullet for every job that comes in.” This of course should not to be confused with a cold Coors Light, as I think in reality, it may already be a “case” for some!
I must say that as nice as silver bullets are (and understandably so), there is a down side. This can and may dull ones diagnostic skills, encouraging pattern failure repairs. A silver bullet typically is the result of someone who had a job that kicked their butt, but they eventually identified a common resolution for the problem. It then became a bulletin, a seminar piece or an article, and now you know the answer to a problem that took someone days to figure out. On one hand, how do you put a value on that? Without question it makes for a nice and profitable day. Yet on the other hand it can blind side you from a different cause that will produce the same complaint. If by this time the job is sold, you have spent time and money on the job and yet the problem remains unresolved.
An uncomplicated example of this is a Ford F550 or 450 producing an intermittent shift solenoid and/or a converter clutch electrical fault code. The silver bullet fix is that a deteriorated internal wiring harness usually causes this. Several jobs are resolved consecutively so that as soon as one of these vehicles comes into the shop, the harness is automatically replaced without any preliminary diagnostics. Then one day it doesn’t fix the problem.
With money and time already invested in the job, it’s now time to diagnose the problem. Because the internal harness has been replaced, the question now becomes, “Is it a solenoid problem or an external wiring problem?” Usually the solenoids get replaced which requires dropping the pan and spending more money. When this doesn’t fix it, the external wiring becomes suspect, but where in the harness does the problem lay? The hours and days it takes to locate this problem now becomes a silver bullet fix in itself, once discovered.
The computer is mounted on the rear inside left fender. The wiring harness travels in a channel under the upper fender. With many of these trucks pulling or carrying heavy loads the body flexes. There is an area near the shock tower where this harness gets pulled taut causing it to rub into a sharp edge. The result is that shift and/or torque converter solenoid wiring is intermittently shorted to ground. Funny thing, once this is learned it becomes the first place to look before thinking solenoids or internal harness problems. I might add to this that in some cases the way the harness is routed up to the engine compartment, heat from the exhaust system is close enough to fatigue the wires in the harness. This is particularly common with diesel engine vehicles and usually speed sensor codes appear first.
Having considered both the upside and downside of silver bullets, I have to concede, there is a diagnostic approach that I believe has been an essential part of the initial diagnosis but is often times overlooked. Ironically enough, I consider this aspect of diagnostics to be a search for the silver bullet in itself, and that is to see if there are any factory reprogramming procedures available to address the malfunction the vehicle is experiencing. If relevant programming is available, a silver bullet may have been discovered.
Torque converter clutch shudder can be caused by a number of possibilities. These are such as, and not limited to, engine drivability issues, the torque converter itself, a malfunctioning solenoid, valve body or incorrect fluid and are all suspects up for grabs. Now add the possibility of a calibration problem being the cause that can only be corrected by reprogramming the computer.
A 2004-05 Buick Rainier, Chevy Trailblazer, GMC Envoy or 2004 Olds Bravado with 4.2L engine equipped with a 4L60E transmission can come into the shop with a code P0741 stored for excessive converter clutch slip accompanied by a complaint of harsh shifts. It also might be noticed that cruise control is inoperative. This complaint was remedied with programming a calibration update.
Many shops were not aware of this so when one of these trucks came in for service, the first approach was to go after the most common cause of TCC slip which is bore wear in the converter clutch regulator valve line up. A byproduct of setting certain DTC’s is harsh shifting, especially the 1-2 shift and P0741 is one of those codes. By replacing the regulator valve assembly in the valve body under ordinary circumstances, P0741 along with harsh shifts would be eliminated. How frustrating it is to do a repair that is usually spot on only to discover it was wasted effort.
A variety of 2010 GM vehicles using the front wheel drive 6T40/6T70/75 transmission may have owners complaining of erratic shifting. Sometimes it shifts well, other times the up-shifts or down-shifts seem unusually delayed. No codes are present. Obviously engine load plays a significant role in shift scheduling so one might take the time to check related sensors. Perhaps Mode 6 might present a sensor on the verge of failing. Or, a simple reprogramming, if available, might be a sensible place to begin. In this case there is: GM bulletin number 09-07-30-016A.
One reason many transmission specialty shops tend to overlook this aspect of diagnostics is that they do not perform the reprogramming themselves nor do they know where to find OEM reprogramming bulletins. In some instances this problem is compounded with being located too far away from dealerships or any other facilities that could perform reprogramming services.
Not knowing where to acquire reprogramming information is the easiest obstacle to remedy. This can be acquired by belonging to a technical hot-line service like ATSG, or online services such as ALLDATA or Mitchell, or go to the manufacturer’s site itself (see the vehicle manufacturer service information websites list). Some of these sites you can access for free while others require a small fee for short periods of time.
For those who have yet to put their toe in the water concerning this subject, my suggestion would be to at least start with GM vehicles.
General Motors makes a free site available (http://tis2web.service.gm.com/tis2web) where you can enter in the vehicles identification number. You then navigate to the appropriate operating system to see what programming is available. Since this is an easy service at no charge to you, check every GM vehicle that comes in to your shop and see how well it profits you. You might be more willing to look into the other OEM sites that charge a little money to look around.
The hesitancy for a shop to learn how to do their own in house programming is not as easy to remedy since it does requires an initial investment of time and money. But for those who have taken the plunge, they are profiting well from it. In addition to their own work, they also seem to be busy programming vehicles for many automotive centers hesitant in doing it for themselves.
A suggestion for those who are contemplating in house reprogramming, start with the manufacturer your facility predominantly repairs. In this way you can recapture your investment and be profitable sooner. I should add that learning reprogramming with BMW vehicles might not be the best choice for beginners as they seem to be the most time consuming and tedious to do.
There is no reason to think that reprogramming will not be a viable means of repair anytime soon. In fact to determine if a reprogramming fix exists has indeed become an essential diagnostic tool. And if it’s discovered that a programming fix is available, who will shoot that silver bullet?
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