Circuit/System Description
WARNING: This page is about a different car, the 2008 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 hybrid battery voltage to verify that the output voltage (36 volts) Is within normal operating value (above 22 volts). If the output voltage is not within this value, this DTC will set.