Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP
Its very common for the TCM to go bad and you get a U0101 code. If it wont program it has to be bad. I have a lot of experience with this problem.
Severed wiring which will take a lot of time. Here's the preliminary tests that should have been done:
1. Verify power and ground to the TCM.
2. Verify 12 volts on the Dk Blue wire at pin 43, this is a "Wake-up" signal that has to present when the key is in the "ACCY and On" positions.
3. Verify a good connection at the TCM.
4. If OK, replace the TCM. Programming is required after installation.
If the preliminary tests were done then it has to be the TCM.