Conditions for Setting the DTC

WARNING: This page is about a different car, the 2010 GMC Sierra, 2010 GMC Cab & Chassis Sierra, 2010 Chevrolet Silverado, and 2010 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The APM wake up signal is open.
The APM does not receive battery voltage.
The powertrain serial data circuits between the SDGM and the APM are open.