2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 2074
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code
(DTC) Type Definitions)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information.
Circuit/System Verification
1. Start the engine.
2. Let the engine run for 1 minute, then turn the key OFF for 30 seconds.
3. Retest for DTC P279C.
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 or neutral.
瀚慖f the scan tool display does not match the transfer case range switch state, repair the transfer case system. Refer to Diagnostic System
Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System Check - Vehicle).
瀚慖f the scan tool matches the transfer case range switch state, continue with testing.
2. Program the ECM with the latest software version and retest for DTCs.
瀚慖f the DTC resets, replace the ECM.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
Control Module References (See: Testing and Inspection/Programming and Relearning) for ECM replacement, setup, and programming.
P279D
DTC P279D
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions)provides 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 (HPCM) monitors the state of the 4WD range signal message, if equipped, over the GMLAN communication
bus. The HPCM 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 HPCM has detected a 4WD range signal rolling count error for 8 seconds.
Action Taken When the DTC Sets
DTC P279D is a Type A DTC.
