Diagnostic Aids

WARNING: This page is about a different car, the 2009 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.

If the ECM is inoperative due to an open in the voltage or ground circuits then DTC U0100 will be set current in the power steering control module (PSCM).
Different DTCs may set in different modules along with this DTC depending on where the fault occurs and the vehicle operating conditions when the fault occurs.