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 drive motor generator power inverter control module (PIM) contains several microprocessors. This diagnostic applies to internal microprocessor integrity conditions within the hybrid powertrain control module (HPCM). The HPCM and each Motor Control Module (MCM) utilize a programmable logic device (PLD) to perform certain input and output functions. At ignition ON, the PLD expects to communicate with the HPCM and both MCMs. The PLD will communicate to MCM 1 over an internal communication circuit when it has established communications with the HPCM. MCM 1 will communicate to the engine control module (ECM) over GMLAN if the PLD has not established communication with the HPCM.