Circuit/System Description
WARNING: This page is about a different car, the 2008 GMC Yukon and 2008 Chevrolet Tahoe. However, it is still accessible from the selected car via links, so may be relevant.
The accessory DC power control module (APM) supplies 42 volts to the power steering control module (PSCM). The PSCM monitors the supplied intermediate voltage to determine if it is within a valid operating range. Damage to components, and incorrect data may occur if the voltage is out of range. The PSCM disables power assist and sets DTC C0895 if high or low intermediate voltage is detected.