Transmission computer problem

[Sparkplug51]

I have a 2004 LS V8 the transmission has been rebuilt twice now. The transmission shop says it is shifting to hard and breaking internal parts. They have suggested that the computer that controls the shifting has a problem. Even after both rebuilds it would shift like it had a old fashion shift kit in it. It would even chirp the rear tires through the first 3 gears. Does anyone know if the transmission has a separate computer or is it tied into the main ECM.

 

[joegr]

There is only the single PCM that controls the engine and the transmission. They do sometimes fail in a way that causes transmission issues with no self diagnostic detection. If the transmission shop has any idea on how to work on this car, then they would not be guessing. There is a fairly easy current test that can be done to know with certainty if the PCM has a problem.

There is an outfit that can repair your PCM for about $200 (I think). If you swap in another PCM, you will need Forscan to marry it to your PATS before the engine will ever start.

While it could be the PCM, I suspect with those symptoms that they are not correctly rebuilding the transmission. Did they sleeve the servo bores?

 

[Sparkplug51]

I will ask about the servo bores today. Not many transmission shops in my area. These guys have been around for decades and that's why I took it to them.