Seven problems related to automatic transmission control module have been reported for the 2002 GMC Envoy. The most recently reported issues are listed below.
Stop engine/low oil pressure display continually comes on and while driving, the vehicle hesitates and at times will stall. After replacing pcm, oil sending unit, throttle body assembly, cleaning the pcv valve and map sensor and multiple other parts, I was told that the dealership did not know what it was and stated that they could replace the cam shaft actuator (for a cost of approx. $885), but they could not guarantee that would resolve the problem. I have taken my vehicle back to the same dealership from 02/14/2011 until 11/07/12 and still unable to fix the problem. I've filed a complaint with GMC manufacturer, but still have not been able to resolve my issues.
I was driving home from the beach (sandy hook national park, NJ) when my service engine soon light came on. I used on star to remote diagnose the code, and was told it was an error in my transmission control module. I immediately called my nearest service center who inspected my truck and informed me that it was my transmission lines that had just simply 'corroded' and that my transmission has almost been running on no fluid. This was shocking considering I maintain good care of my 2002 Envoy and had seen no sign of leaking transmission fluid but was informed it was somehow all over the bottom of my truck. They were able to fix the lines for a cost of 690 dollars, but I still feel that something is not quite right with this situation and have talked to others with similar issues.
Continued electrical problems with 2002 GMC Envoy. Such as on-star telephone along with radio/cd player, all four doors failing to lock or open including the back hatch. Service air bag light and engine check lights coming on. Reprogram engine/transmission module, also telephone antenna replaced, short in wiring located due to rubbing/pinching during construction, replaced wiring harness. Hundreds of dollars required to identify short in wiring. Transmission operates sluggish until warmed-up vehicle feels as if the brakes are on until it has moved several blocks.
While driving at 65 mph engine shuts off; would not restart first try. Would start a little later. Went to dealer, reprogrammed pcm with latest calibration update. Second time happened at 70 mph.
Pcm defect.
Consumer states the vehicle will slip out of overdrive and into first gear, which results in the vehicle losing power. There is a warning light that will come on which will read reduce engine speed, the dealer replaced the pcm/vcm but this did not correct the problem, front end squeaks when turning and driving, . Mr.
Consumer states while comiing down a hill pcm shorted out. As a result, driver lost all electrical functions. Steering wheel got really stiff. Brake pedal became hard to press.