Test Description

WARNING: This page is about a different car, the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 Chevrolet Silverado, and 2002 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to the step numbers on the diagnostic table.

2) - This step tests the electrical function of the front axle actuator. This step helps determine between mechanical and electrical malfunctions.
3) - This step tests for proper power and ground at the front axle actuator.
4) - This step tests the operation of the axle actuator control circuit.
5) - This step helps determine if the transfer case shift control module is able to monitor the front axle switch.
6) - This step tests the axle switch signal circuit for an open or high resistance.
7) - This step measures the voltage between the ignition 3 voltage circuit and ground.
8) - This step tests the axle actuator control circuit for an open or high resistance.
9) - This step inspects the front axle for a mechanical malfunction.
10) -. This step tests for open fuse in the ignition 3 voltage circuit.

Fig 1: Front Axle Will Not Engage Diagnosis (Steps 1-5)

Courtesy of GENERAL MOTORS CORP.

Fig 2: Front Axle Will Not Engage Diagnosis (Steps 6-15)

Courtesy of GENERAL MOTORS CORP.