C0397

DTC C0397

Diagnostic Instructions

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



DTC Descriptor
DTC C0397 64
- Transfer Case Clutch Performance Actuator Slipping




Diagnostic Fault Information






Circuit/System Description

The transfer case in the Auto 4WD mode attempts to correct for slip by monitoring the front and rear wheel speed sensors. If the transfer case is unable to correct for slip when there is a difference between the front and rear speed sensors the transfer case will apply the clutch. If the transfer case in unable to correct this slip and the clutch begins to heat up based on a thermal model inside the transfer case control module this DTC will be set.


Conditions for Running the DTC

* The ignition is ON.
* System voltage is 10.5-18 volts.



Conditions for Setting the DTC

The transfer case is unable to correct slip due to a clutch overheat condition as a result in surpassing the thermal model that is stored in the transfer case control module.


Action Taken When the DTC Sets

* Shifting is still possible but in a reduced capacity which may cause undesirable slip correction events.
* The SERVICE 4WD indicator remains illuminated for the remainder of the current ignition cycle.



Conditions for Clearing the DTC

* The transfer case shift control module clears the DTC if the condition for setting the DTC is not currently present.
* A history DTC clears after 40 consecutive warm up cycles without a fault present.
* History DTCs can be cleared using a scan tool.



Reference Information
Schematic Reference

Transfer Case Control Schematics (MP 3023/3024-NQH - Transfer Case)
Connector End View Reference

Component Connector End Views
Electrical Information Reference

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

Scan Tool Reference

* Scan Tool Data List (Scan Tool Data List)
* Scan Tool Data Definitions (Scan Tool Data Definitions)



Diagnostic Aids

Motor control A shorting to motor control B could cause this DTC.


Circuit/System Testing

Check for EBCM DTCs as an incorrect speed sensor reading could cause this issue. If no other DTCs are found then refer to Transfer Case Disassemble (Transfer Case Disassemble) to inspect for possible clutch damage.


Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.


Transfer Case Disassemble (Transfer Case Disassemble)