Quote Originally Posted by Meister View Post
Turns out it was an aftermarket transmission controller improperly wired causing the problem. All is fixed now. Thanks for everyone helping out
It seems odd that a miswired transmission controller caused a P2138 code to appear. Was the transmission controller wired to one of the APPS circuits?

I am having a similar issue - P2138 and a few other codes. ECM low reference circuits for the APPS show between 15 and 50 ohms of resistance, while they should be 5 ohms. That