Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
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.
- The FRONT LED will
- turn ON SOLID when the front axle is locked
- turn ON BLINKING when the front axle is attempting to lock
- turn ON BLINKING when a lock front axle request is received but conditions to lock are not correct
- turn OFF when the axle is UNLOCKED
- turn ON FAST BLINKING when there is a fault detected for the front axle
- The REAR LED will
- turn ON SOLID when the rear axle is locked
- turn ON BLINKING when the rear axle is attempting to lock
- turn ON BLINKING when a lock rear axle request is received but conditions to lock are not correct
- turn OFF when the axle is UNLOCKED
- turn ON FAST BLINKING when there is a fault detected for the rear axle
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.