I think I have stumbled onto the answer on a GM website. Appears that there was one controller assembly 12225995 for AWD with traction control and another controller assembly 12227273 for FWD with traction control. I am guessing that if the AWD controller was put into a vehicle without communication to and from a rear drive axle, an error message would occur.
Looks like I have bought a very expensive assembly for a song but it only fits
AWD. Will look to trade "down" the AWD controller for a FWD controller.
They both may be identical PLC units that could be reprogrammed by someone who has the right tools but I would have to look at the part numbers stamped inside the mini computer to see.
Thanks for your help Saturn!
Sunday, July 5th, 2015 AT 5:06 PM