Also trans doesn't shift and PRD123 DOESN'T WORK

 

You need to look over the GMLAN wires from the TCM.

Mice love the aribox as a nest but you've been in there doing swaptronics and didn't mention removing a mouse house.

 

Yeah luckily no mice but did see one wire looked kind of shady wasn't broken just like it was pinched I ordered a Haynes book for rhe car and will try to test the wires going to tcm and to the trans when it comes.

 

If it's complaining about TCM communication it's likely the GMLAN wires to the PCM etc
The wiring down to the 4T65E is full analog to things like the shift control solenoids, TCC, PCS, VSS, gear position ...

 

Whats everyone's thoughts on taking it to the chevy dealership can't find any shop that wants to take on the job but scared to be hit over my head with repair bill.

 

The dealer would be an absolute dead last resort. The parts changers at the dealership will quote you a replacement harness when you need a few wires repaired with solder and heatshrink or a few replacement terminals with wire tails installed in a connector then soldered and heatshrinked into the harness.
You need to find the shop in your area that other shops, including the dealerships, send their electrical work to. There is one. It'll take some legwork to find them but they exist.

 

Okay thanks going to be my project for first thing Monday

 

If the TCM is not communicating check your power and grounds to the TCM
Then check the Class II databuss wires and Comms with a scope

 

Problem fixed it was a broke wire frome fuse box not getting connection to the TCM shop fixed and rewired for 360 dollars always thought that was the problem almost changed the trans and would have had same problem. Sometimes follow your first mind could be right some of the time

 

Owch on the price... but they actually fixed the problem so it was worth doing.
Far better than having the parts changers at the dealership change out the TCM for a grand or worse yet the transmission for a lot more and give it back to you with the problem unresolved.

 

I guess we have to pay to play. Thanks everyone for all of your suggestions.