Test A: The Front Axle Does Not Engage/Disengage Correctly

Pinpoint Test A: The Front Axle Does Not Engage/Disengage Correctly

Refer to Vehicle/Diagrams, Four-Wheel Drive Systems for schematic and connector information.

Normal Operation

In two wheel drive (2WD), the 4X4 control module (PCM) supplies a ground path to the integrated wheel end (IWE) solenoid to apply vacuum to the IWEs (disengaging the front hubs from the front axle). In four wheel drive (4WD), the 4X4 control module (PCM) does not supply the ground path to the IWE solenoid, vacuum is not applied to the IWEs and an internal spring keeps the hubs engaged.

- DTC C1979 IWE Solenoid Circuit Failure - IWE solenoid open circuit or short short to ground sensed by the 4X4 control module (PCM) on circuit 605 (RD).

- DTC C1980 IWE Solenoid Short to Battery - IWE solenoid short to battery sensed by the 4X4 control module (PCM) on circuit 605 (RD).


This pinpoint test is intended to diagnose the following:

^ Mode indication switch
^ IWE
^ IWE solenoid
^ Transfer case
^ Vacuum leaks
^ Front axle assembly
^ 4X4 control module (PCM)
^ Fuses
^ Wiring, terminals or connectors

A1-A3:

A4-A6:

A7-A10:

A11-A14:

A15-A17:

A18-A19:

A22-A24:

A25-A28:

A29-A32: