Technically Speaking
- Subject: Reprogramming vehicle computers
- Unit: Toyota U240; Chrysler 48RE
- Vehicle Applications: Toyota Corolla & Matrix, 2005-06; Dodge Ram diesel pickup, 2003-05
- Essential Reading: Rebuilder, Diagnostician
- Author: Wayne Colonna, ATSG, Transmission Digest Technical Editor
I find any articles or training related to the topic of re-flashing or reprogramming computers to be of great interest and a great help to me and to all transmission technicians because it has become a very prominent repair procedure. In fact, looking through the past 10 years of OE bulletins, I find that the ratio of actual repairs versus computer reprogramming has changed dramatically, totally favoring computer reprogramming.
Reading what some of these reprogramming procedures covered in the bulletins’ fixes is also interesting, and I am, of course, speaking about fixes specific to automatic transmissions. We have seen shift-overlap problems, TCC shudders, shift cycling, delayed engagements and shift-timing issues all corrected by reprogramming. There are many others related to de-sensitizing code setting by altering the parameters that cause a sensor to set a code and so on.
Sometimes the computer has to be replaced to fix a problem rather than a re-flash or programming. One example of this is with 2005-06 Toyota Corollas and Matrixes with the 1ZZ-FE engine and the U240-series FWD transmission that exhibits a harsh-shift condition with code P2716, pressure-control solenoid D electrical (TC014-06). This is good to know ahead of time so you are not wasting your time chasing down solenoids and inspecting wires.
But getting back to reprogramming, just recently I saw a customer-satisfaction bulletin (07201) by GM that really caught my attention. I am amazed at how many problems a simple little reprogramming procedure can resolve. It has to do with 4WD 2007 Chevrolet Silverados from 7E500353 to 7E568425 and 4WD GMC Sierras from 7E500999 to 7E590686 that crack the transmission housing or transfer-case adapter because of “vibration.” The fix is to reprogram the body control module (BCM) so that the vehicle will never exceed highway speeds of 138 km/hour (86 mph) and thus not vibrate enough to crack the case or transfer-case adapter. This reprogramming procedure is free of cost from the dealer to the owner until Aug. 31, 2008. Isn’t that something!
Another scenario that gave me a bit of a chuckle is with Dodge vehicles. In March 2006 Dodge issued safety-recall bulletin E17 for 2003-2005 Dodge Ram pickups (6 or C in the eighth VIN position) equipped with the 5.9-liter diesel and the 48RE transmission. This recall was issued to re-flash the computer so that it can alert the driver when a door has opened without the selector in the Park position while the engine is running. To alert the driver, the horn starts blowing and the headlights and the PRNDL display begin to flash.
This is, of course, a safety issue, but what has occurred is if a vehicle that falls under this recall is taken to the dealer for any service, it will automatically receive this re-flash, with or without customer approval or notification. If the driver of this vehicle likes to open his door while backing up to see better, the out-of-park alarm system will be initiated and he will wonder what is wrong, as this never occurred previously. Since the PRNDL display begins to flash, some technicians have assumed that the range sensor is the cause and replaced the sensor to no avail. We also have seen door switches that become dirty or start sticking, indicating that the door never closed and initiating the out-of-park alarm system as soon as you move the selector lever from park.
So it’s interesting not only to learn and be trained on reprogramming procedures but also to learn what they fix! There could be much time saved on trying to fix something that isn’t broken or fixing something that keeps breaking.
