• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
The hybrid powertrain control module (HPCM) uses the GMLAN to signal the engine control module (ECM) that the hybrid system is requesting malfunction indicator lamp (MIL) illumination. This happens when the HPCM has determined that a failure affecting the hybrid system has occurred. When the ECM receives the message from the HPCM, DTC P0AC4 will set.
The ignition is ON.
The HPCM is requesting MIL illumination.
DTC P0AC4 is a Type A DTC.
DTC P0AC4 is a Type A DTC.
DTC P0AC4 can not be cleared from the ECM until the related hybrid codes have been cleared.
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Refer to Diagnostic Trouble Code (DTC) List - Vehicle to correct any hybrid DTCs.