P1AED

DTC P1AEC-P1AEF

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.

DTC Descriptors
DTC P1AEC
- Drive Motor 1 Control Module Hybrid Battery System Voltage

DTC P1AED
- Drive Motor 2 Control Module Hybrid Battery System Voltage

DTC P1AEE
- Drive Motor 1 Control Module Hybrid Battery System Voltage High

DTC P1AEF
- Drive Motor 2 Control Module Hybrid Battery System Voltage High

Circuit/System Description

The drive motor generator power inverter control module (PIM) contains two motor control modules (MCMs). Each MCM measures hybrid battery high voltage with several internal sensors. The battery energy control module (BECM) also monitors high voltage with several internal sensors. The BECM high voltage measurement is broadcast over GMLAN.

P1AEC and P1AED

The MCM compares the values in order to verify the hybrid battery high voltage measurement is accurate.

P1AEE and P1AEF

The MCM monitors for high voltage that is greater than the system allows during normal operation.

Conditions for Running the DTC

* The high voltage contactor relays are closed.
* Ignition voltage is 8-18V.

Conditions for Setting the DTC

P1AEC and P1AED

The MCM hybrid battery high voltage sensor measurements are greater than 30V apart.

P1AEE and P1AEF

The MCM hybrid battery high voltage sensor monitors greater than 475V.

Action Taken When the DTC Sets

* DTCs P1AEC, P1AED, P1AEE and P1AEF are Type A DTCs.
* The PIM commands the battery energy control module (BECM) to open the high voltage contactor relays.

Conditions for Clearing the DTC

DTCs P1AEC, P1AED, P1AEE and P1AEF are Type A DTCs.

Diagnostic Aids

DTCs P1AEC and P1AED compare the MCM measured high voltage to the BECM measurement of high voltage which is broadcast over GMLAN. Conditions that cause the BECM to improperly measure high voltage or a failure of the BECM to transmit its high voltage value may set this DTC.

DTCs P1AEE and P1AEF indicate that the high voltage contactor relays may have opened while large current flow was present. Conditions such as loss of BECM power or ground or removal of the high voltage manual disconnect while the vehicle was driving create a voltage surge that may set this DTC.

Reference Information
DTC Type Reference

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

Circuit/System Verification

1. Inspect for DTCs P0ABB, P0ABC, P0ABD, loss of communication with the BECM U-code DTCs, or any other concern that would indicate high voltage to the PIM was interrupted while high current was present.

• If the specified DTCs are set, or high voltage interruption is suspected, diagnose them first. Refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code (DTC) List - Vehicle).

2. Clear the DTC information.
3. Ignition OFF for 1 minute.
4. Ignition ON.
5. Retest for DTCs P1AEC, P1AED, P1AEE and P1AEF.

If the DTC resets, program the PIM with the latest software version and recheck for DTCs. If the DTC resets after programming or if the PIM already contains the latest software version, replace the PIM.

Repair Instructions

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

Control Module References (Programming and Relearning) for PIM replacement, setup, and programming.