Conditions for Setting the DTC

WARNING: This page is about a different car, the 2009 GMC Sierra, 2009 GMC Cab & Chassis Sierra, 2009 Chevrolet Silverado, and 2009 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The HPCM does not receive voltage from the SDGM on the wake up signal circuit.
The wake up circuit between the SDGM and the APM is shorted to voltage.
Any of the 4 PTLAN circuits connected to the HPCM are open.