Inspection And Verification

CAUTION: Diagnosis by substitution from a donor vehicle is NOT acceptable. Substitution of control modules does not guarantee confirmation of a fault and may also cause additional faults in the vehicle being checked and/or the donor vehicle.

NOTE: Check and rectify basic faults before beginning diagnostic routines involving pinpoint tests.

Verify the customer concern.

Visually inspect for obvious signs of mechanical or electrical damage.

VISUAL INSPECTION

Mechanical	Electrical
Headlamp leveling motor(s) and linkage(s) condition and installation Lighting control switch condition and installation Steering column left multifunction switch condition and installation	Fuses Wiring harness Loose or corroded connector(s) Battery Junction Box (BJB) Central Junction Box (CJB) Headlamp Leveling Control Module (HLCM) Engine Control Module (ECM) Anti-lock Brake System (ABS) control module Air suspension control module Local Interconnect Network (LIN) circuits Controller Area Network (CAN) circuits

If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
If the cause is not visually evident, verify the symptom and refer to the Symptom Chart, alternatively check for Diagnostic Trouble Codes (DTCs) and refer to the relevant DTC Index.