2019 CTS-V TCM replacement and tuning code P0700

[prlsa]

I am in the process of finishing up my car tuning but I am having an issue with the TCM. I bought a new TCM from HP Tuners already unlocked and ready for tuning but once I connect it and do the TCM replacement process on HP Tuners, it quickly throws a code of P0700. I tested it and downshifting from 3-1 is hard as well as putting it in reverse. I installed back the original TCM and the code went away and transmission started shifting correctly. Is there a process I'm missing? Is the TCM faulty?

[prlsa]

I am in the process of finishing up my car tuning but I am having an issue with the TCM. I bought a new TCM from HP Tuners already unlocked and ready for tuning but once I connect it and do the TCM replacement process on HP Tuners, it quickly throws a code of P0700. I tested it and downshifting from 3-1 is hard as well as putting it in reverse. I installed back the original TCM and the code went away and transmission started shifting correctly. Is there a process I'm missing? Is the TCM faulty?

Issue resolved thanks to HP Tuners support.

[Logang717]

I know this is old but what was the issue!?