Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Circuit/System Description
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.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.