P0AC4

DTC P0AC4

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (with HP2) (Initial Inspection and Diagnostic Overview)Diagnostic System Check - Vehicle (without HP2) (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.

DTC Descriptor
DTC P0AC4
- Hybrid Powertrain Control Module Requested MIL Illumination

Circuit/System Description

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.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

The HPCM is requesting MIL illumination.

Action Taken When the DTC Sets

DTC P0AC4 is a Type A DTC.

Conditions for Clearing the MIL/DTC

DTC P0AC4 is a Type A DTC.

Diagnostic Aids

DTC P0AC4 can not be cleared from the ECM until the related hybrid codes have been cleared.

Reference Information
DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

Refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code Descriptions) to correct any hybrid DTCs.