I'm fighting an issue with my g8 and am out of ideas. I'll try to keep it to important bits. The transmission locked into 4th after a pull and threw a P0797 for solenoid c stuck on. While trying to figure out what was going on, I'm pretty sure it roasted all the clutch packs as they were all burnt up and the transmission did not slip at all prior to this. Only thing found wrong was the tcm. No hard part damage, etc.
A new 6l80 from gm was installed, the shop attempted to program it and couldn't. Thought was the tcm was incorrect or something of that nature. So it was pulled out and I built the original transmission.
Purchased a remanned tcm that was pre-programmed. I installed my tcm tune in it and got limp mode with no tutd. Tried multiple different OS with no change. It was giving code u0101 for loss of communication with TCM. But I could see and log TCM outputs. I took it to a local GM dealer to have them attempt programming. They get an error stating some information is missing.
GM dealer installs a brand new TCM, try to flash it with same results and error.
GM tech said the harness and connector are both good.
I installed my oem stock tune to see if ecm tune was somehow causing issues. No change. GM tech is at a loss, I'm at a loss.
Has anyone else had a similar issue and were able to get it resolved. This is making me want to pull out my hair and burn the car to the ground.