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P1AFE




DTC P1AF8 or P1AFE

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 P1AF8
- Drive Motor 1 Control Module Shutdown Performance

DTC P1AFE
- Drive Motor 2 Control Module Shutdown Performance

Circuit/System Description

The drive motor generator power inverter control module (PIM) contains two motor control modules (MCMs) and the hybrid powertrain control module (HPCM). Each MCM operates its respective drive motor generator based upon HPCM commands. Each MCM controls the speed, direction and output torque of its respective drive motor generator through the sequencing actuation of high current switching transistors called insulated gate bipolar transistors (IGBTs). Each drive motor generator operates utilizing 3 phase alternating current (ac) electricity. Each IGBT operates a single phase of the drive motor generator. Each phase is individually identified as U, V and W. Each MCM monitors the current of each phase in order to detect PIM overcurrent conditions.

At ignition ON, each MCM tests the integrity of the drive motor phase circuits by sequencing the IGBTs between open and shorted states while simultaneously injecting a large amount of current into the phase circuits. The individual phase current sensors should all indicate similar current flow and the current flow should increase and decrease at known rates based upon the inductance of the drive motor.

Conditions for Running the DTC

* The ignition is transitioned to ON.
* Ignition voltage is 8-18 volts.
* High voltage has been enabled.

Conditions for Setting the DTC

The control module has detected a phase current that indicates an open or shorted 3 phase circuit condition exists.

Action Taken When the DTC Sets

* DTCs P1AF8 and P1AFE are Type A DTCs.
* The HPCM commands the battery energy control module (BECM) to open the high voltage contactor relays.

Conditions for Clearing the DTC

DTCs P1AF8 and P1AFE are Type A DTCs.

Diagnostic Aids

* An intermittent loss of battery power to the drive motor generator power inverter control module (PIM) may set this DTC.
* An open or shorted 3 phase circuit, prior to ignition ON, may set this DTC.

Reference Information
Schematic Reference

Hybrid Controls Schematics ()
DTC Type Reference

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

Circuit/System Verification

1. Clear the DTC information.
2. Turn the ignition OFF for 1 minute.
3. Turn the ignition ON.
4. Retest for DTC P1AF8 or P1AFE.

Circuit/System Testing

1. Verify that DTCs P0C01, P0C04, P0BFD, or P0BFE is not set.

• If the DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code (DTC) List - Vehicle).

Danger: Always perform the High Voltage Disabling procedure prior to servicing any High Voltage component or connection. Personal Protection Equipment (PPE) and proper procedures must be followed.


The High Voltage Disabling procedure will perform the following tasks:


* Identify how to disable high voltage.

* Identify how to test for the presence of high voltage.

* Identify condition under which high voltage is always present and personal protection equipment (PPE) and proper procedures must be followed.


Failure to follow the procedures exactly as written may result in serious injury or death.


2. Disable the high voltage for servicing at the drive motor generator control module assembly cable connections. Refer to High Voltage Disabling ().
3. Inspect for damaged 3 phase cables between the PIM and the transmission.

• If damage is observed, replace the 3 phase cables.

4. Inspect the 3 phase cable terminal fasteners for the proper torque and for arc-flash damage.

• If any fasteners were loose and no arc flash damage is present, torque the fasteners and re-assemble the vehicle. Retest for the DTC.
• If any fasteners were loose and arc flash damage is present, replace the PIM and the 3 phase cable assembly.

5. Remove the 3 phase cable assembly from the PIM distribution box. Refer to Generator Control Module 3-Phase Cable Assembly Replacement ().
6. Test the resistance of each phase by measuring between the following circuits with a DMM.

* Phase U and phase V
* Phase U and phase W

• If you measure 0.5 ohms or less, continue with Circuit/System Testing.
• If you measure more than 0.5 ohms, proceed to Open Phase Testing Procedure below.

7. Test the resistance to ground for each phase of the applicable drive motor generator by measuring between the following points with a DMM.

* Phase U terminal and chassis ground
* Phase V terminal and chassis ground
* Phase W terminal and chassis ground

• If infinite resistance is measured, replace the 3-phase cable assembly and the drive motor generator assembly that corresponds to the set DTC and retest for the DTC. If the DTC resets replace the PIM.
• If less than infinite is measured, continue with Circuit/System Testing.

8. Remove the 3-phase cable assembly from the transmission. Refer to Generator Control Module 3-Phase Cable Assembly Replacement (). Ensure the terminals are not contacting chassis ground.
9. Retest the resistance to ground for each phase of the 3-phase cable. Measure between the following points with a DMM.

* Phase U terminal and shield ground
* Phase V terminal and shield ground
* Phase W terminal and shield ground

• If infinite resistance is measured, replace the applicable drive motor generator.
• If less than infinite is measured, replace the generator control module 3-phase cable assembly.

Open Phase Testing Procedure
1. Remove the 3 phase cable assembly cover from the transmission and inspect the 3 phase cable terminal fasteners for the proper torque and for arc-flash damage. Refer to Generator Control Module 3-Phase Cable Assembly Replacement ().

• If any fasteners were loose and no arc flash damage is present, torque the fasteners and re-assemble the vehicle. Retest for the DTC.
• If any fasteners were loose and arc flash damage is present, replace the applicable drive motor generator assembly and the 3 phase cable assembly.

2. Disconnect the 3 phase cable assembly from the transmission. Refer to Generator Control Module 3-Phase Cable Assembly Replacement ().
3. Test each cable for continuity from the PIM connection terminal to the transmission connection terminal.

• If you measure greater than 0.5 ohms, replace the 3 phase cable assembly.
• If you measure 0.5 ohms or less, replace the applicable drive motor generator assembly.

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
* Generator Control Module 3-Phase Cable Assembly Replacement ()
* Drive Motor with Generator Assembly Removal - 1st Position (8. Drive Motor with Generator Assembly Removal - 1st Position) or Drive Motor with Generator Assembly Removal - 2nd Position (13. Drive Motor with Generator Assembly Removal - 2nd Position)

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