The front axle control circuit consists of an electric motor actuator which engages and disengages the front axle. The front axle actuator motor consists of a permanent magnetic motor, a worm gear controlled plunger, a front axle switch and an electronic control circuit within the actuator assembly.

The front axle actuator consists of the following circuits:

When a shift to AUTO 4WD, 4HI, or 4LO is requested, the transfer case shift control module engages the front axle by grounding the front axle control circuit through a current limiting driver.

Schematic Reference

Transfer Case Control Schematics

Connector End View Reference

Transfer Case Control Connector End Views

Electrical Information Reference

DTC Type Reference

DTC Symptom Description

Scan Tool Reference

1. If this is occurring without DTC C0379 setting it is likely related to a mechanical issue. Refer to Four-Wheel Drive Does Not Engage.
2. If no mechanical issue is found replace the front axle actuator.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.