Circuit/System Description
WARNING: This page is about a different car, the 2009 GMC Sierra and 2009 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The drive motor generator power inverter module (PIM) contains two motor control modules (MCM) and a hybrid powertrain control module (HPCM). The HPCM and both MCMs share the PIM ignition voltage circuit, battery voltage circuits and chassis ground.