Test Description
The numbers below refer to the step numbers on the diagnostic table.
- 2: This step determines if the differential lock is engaged due to an electrical condition or a mechanical condition.
- 3: This step determines if the differential lock high control circuit is shorted to power and if the differential low reference circuit is shorted to ground.
- 4: This step indicates the transfer case shift control module needs replaced.
- 5: This step checks for the possibility of the rear differential mechanically binding causing it to stay on.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Differential Lock Schematics Connector End View Reference: Component Connector End Views |
|||
| 1 | Did you perform the Diagnostic System Check-Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 | Disconnect the rear differential lock harness from the rear differential lock coil pigtail at the rear differential, and verify the fault is present. Refer to Locking Differential Diagnosis . Does the system operate normally? |
Go to Step 3 | Go to Step 5 |
| 3 | Check the rear differential lock high control circuit for a short to power and the differential lock low reference for a short to ground. Refer to Circuit Testing
and Wiring Repairs
. Was the condition found and corrected? |
Go to Step 6 | Go to Step 4 |
| 4 | Replace the transfer case shift control module. Refer to Control Module References
for replacement, setup, and programming. Was the repair completed? |
Go to Step 6 | - |
| 5 | Replace the electronic locking differential locking mechanism and/or side gear. Refer to Locking Differential Disassemble and Locking Differential Assemble . Was the condition repaired? |
Go to Step 6 | - |
| 6 |
|
Go to Step 1 | System OK |