I have been fighting with this problem for a long time now. Problem is the transmission and car is not moving at all, gear lights did work. I got blink codes 2134,2131,3221 only once, after that TCU went offline totally, all gear lights are on.
I did get new TCU because I tought that the original went bad.
Anyway now it work this way: Gear is in N-position, turn the key power ON, you can move the stick to every other gears and lights on dash do work, but, when you put it on R-position, TCU go OFF again and all gear signal lights go ON. TCU won't star after battery cable is off for few minutes, only when I switch other TCU on and put gear on N, D, 1 or 2 position gear shifting works again, until I put it again to R and TCU goes OFF. One day is was able to move car on R-gear two times, then it died, D-gear did not work.
I have cleaned all 4 connectors on transmission. Could this problem be inside on valve body or R-solenoid? How you measure the solenoids?