OBD is just how the code is outputted. there is OBDI and OBDII. OBDII can use a code puller, OBDI requires you to look through a sight window and count the flashing or jumper a cable and count the flashes of the CEL.

one of the suggestions I read is to unplug the alt fuse or just the neg battery terminal for 30sec-1min. drive around and see if that cures your problem until you come to a stop. if so, then it says it is your TCU, but since you had 2 "bad" TCU's it makes me think its a different sensor.