Circuit/System Description
WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
The starter/generator control module (SGCM) monitors the performance to detect 12-volt DC wire electrical failure by comparing the 12-volt input to the 12-volt output values. If the difference is greater than 5 volts, the DTC sets.