Code P1968. Sometimes works fine then all the sudden nothing?

Question

Replaced TCM last week, scanned & test drove. Vehicle was fine.
Today it came back. Hooked up scanner but it would not communicate with PCM.
Shut engine down. Walked away for a short time.
Came back & restarted engine. Everything was working a should be.
If this is an electrical problem where should I start looking?

Answer 1

P1698 No message from the TCM

The correcr code for this is P1698 , what also cause this is a failed TCM, where the TCM does not power up,just make sure the connection are making good contact, If this repeats the TCM IS FAILING