Front Axle Will Not Disengage

Front Axle Will Not Disengage








Circuit Description
The front axle control circuit consists of an electric motor actuator which engages arid the front axle. The front axle actuator's motor consists of a Permanent Magnetic (PM) motor, a worm gear controlled plunger, a front axle switch and an electronic control circuit all within the actuator assembly.
The front axle actuator has four circuits connected to it, a front axle feed circuit, front axle ground circuit front axle control circuit and a front axle switch circuit.
Whenever 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.

Test Description
The numbers below refer to the step numbers on the diagnostic table.
2. Tests the electrical function of the front axle actuator. Helps determine between mechanical and electrical malfunctions.
3. Tests for proper power and ground at the front axle actuator.
4. Tests the operation of the front axle control circuit.
5. Tests the electrical function of the front axle actuator control circuit.
6. Tests for proper supply voltage to the front axle actuator.
7. Tests for open fuse in the front axle feed circuit.
8. Tests the front axle control circuit for an open or high resistance.
9. Tests the front axle switch circuit for an open or high resistance.
10. Helps determine if the front axle actuator has a mechanical malfunction.
11. Tests the front axle switch circuit for a short to voltage.
12. Inspect the front axle for a mechanical malfunction.