Diagnosis And Testing - Differential - TRU-LOK: Notes

The control module for the electronically locking differentials detects faults from input signal/messages, sensors, solenoids, and drivers/relays and report the corresponding Diagnostic Trouble Code (DTC).

The lighting strategy for the axle lock switch.

1. The FRONT LED will
   1. turn ON SOLID when the front axle is locked
   2. turn ON BLINKING when the front axle is attempting to lock
   3. turn ON BLINKING when a lock front axle request is received but conditions to lock are not correct
   4. turn OFF when the axle is UNLOCKED
   5. turn ON FAST BLINKING when there is a fault detected for the front axle
   6. The REAR LED will
   7. turn ON SOLID when the rear axle is locked
   8. turn ON BLINKING when the rear axle is attempting to lock
   9. turn ON BLINKING when a lock rear axle request is received but conditions to lock are not correct
   10. turn OFF when the axle is UNLOCKED
   11. turn ON FAST BLINKING when there is a fault detected for the rear axle