Differential Lock Inoperative

Differential Lock Inoperative

Circuit Description
The differential clutch pump actuator check valve assembly is a pulse width modulated actuator mounted to the rear drive assembly. Ignition voltage is supplied to the clutch pump actuator check valve through a fused circuit. The PCM controls the actuator with a negative duty cycle. The actuator controls the fluid supply to the pump inlet in the rear drive assembly. When the actuator is commanded OFF, the PCM detects high voltage. When the actuator is commanded ON, the PCM detects low voltage. At engine start-up, the actuator is turned ON at 49-90 percent duty cycle for 3 seconds, then drops to 16-28 percent for holding. Every 30 seconds, the duty cycle is ramped to 49-90 percent for 0.5 second, then back to 16-28 percent.

Test Description








The numbers below refer to the step numbers on the diagnostic table.
3. This step tests the ignition 1 voltage circuit for proper voltage.
4. This step tests the ground circuit for an open.
5. This step tests the axle actuator control circuit duty cycle.
6. This step tests the axle actuator control circuit for an open or short.