P279D

DTC P279D

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 Instructionsprovides an overview of each diagnostic category.

DTC Descriptor
DTC P279D
- Four Wheel Drive (4WD) Range Signal Circuit

Circuit/System Description

The hybrid powertrain control module monitors the state of the 4WD range signal message, if equipped, over the serial data circuits. The hybrid powertrain control module uses this message to determine motor torque required and transmission shifting, there are no external circuits involved.

Conditions for Running the DTC

The engine is running.

Conditions for Setting the DTC

The hybrid powertrain control module has detected a 4WD range signal rolling count error for.5 seconds.

Action Taken When the DTC Sets

DTC P279D is a Type A DTC.

Conditions for Clearing the DTC

DTC P279D is a Type A DTC.

Diagnostic Aids

When attempting to set hybrid powertrain control module internal DTCs, run the engine for at least 1 minute, and then shut the engine off for 30 seconds. Following this procedure will allow for a complete hybrid powertrain control module shutdown.

Reference Information
Schematic Reference

Automatic Transmission Controls Schematics 2ML70 - Automatic Transmission
Connector End View Reference

Component Connector End Views Connector End Views By Name
Electrical Information Reference

* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference

Control Module References Programming and Relearningfor scan tool information.

Circuit/System Verification

Run the engine for 1 minute, then ignition OFF for 30 seconds.

The DTC should not reset.

Circuit/System Testing

1. Observe the 4WD Signal in the ECM Data List. The 4WD signal should display Enabled when you shift into 4WD and Disabled when you shift into 2WD.

• If the scan tool display does not match the transfer case range switch state, repair the transfer case system refer to Diagnostic Starting Point - Vehicle Diagnostic Starting Point - Vehicle.

• If the scan tool matches the transfer case range switch state, continue with testing.

2. If the DTC is set, program the T6 power inverter module. If the DTC resets, replace the T6 power inverter module.

Repair Instructions

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

Control Module References Programming and Relearningfor Drive Motor Power Inverter Module replacement, programming and setup.