U0101 - TCM not communicating - 2010 CTS-V
Code U0101 came up today while I was working on buttoning up a twin turbo build. I poked around with HPTuners to see if I could read the TCM but it says "Requesting access.....Connection Timed Out..........FAILED" and I can't get it to connect. Communication with the ECM works fine (Read and write).
I unplugged everything from the ODBII port, disconnected the battery for 1/2 hour hoping to reset the CAN, checked the plug / wires / pins / connector in the trans and blew some air in them to remove any possible debris, cleaned the battery posts and all the grounds, cleared the codes and it comes back immediately when I turn the key on.
"Stabilitrac Off"
"Parking assist Off"
"Service Stabilitrac"
"Service Tire Monitor System"
"Service Traction Control"
The car is stuck in some type of "limp" mode and seems like it is stuck in 3rd gear (Reverse works too). No gear indicator on the dash either.
I drove it two days ago while logging some around town driving and zero transmission related problems.
Not sure what else I could try to get this bitch to recognize the TCM at all.
Any suggestions or recommendations are welcome!