Diagnostic Test

CHECK IF THE DTC IS ACTIVE
1. Turn the ignition on, headlamps on.
2. With the scan tool, read Automatic Headlamp Leveling Module (AHLM) DTCs.
  Is this DTC active?
  
  Yes
  - Go To 2
  No
  - Go To 5
CHECK THE (L963) REAR HEADLAMP LEVELING SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the AHLM harness connector.
3. Disconnect the Rear Headlamp Level Sensor harness connector.
4. Measure the resistance between ground and the (L963) Rear Headlamp Leveling Sensor Signal circuit.
  Is the resistance above 5.0 Ohms?
  
  Yes
  - Repair the (L963) Rear Headlamp Leveling Sensor Signal circuit for a short to ground.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 3
CHECK THE (L963) REAR HEADLAMP LEVELING SENSOR SIGNAL CIRCUIT FOR AN OPEN
1. Measure the resistance of the (L963) Rear Headlamp Leveling Sensor Signal circuit between the AHLM harness connector and the Rear Headlamp Level Sensor harness connector.
  Is the resistance above 5.0 Ohms?
  
  Yes
  - Repair the (L963) Rear Headlamp Leveling Sensor Signal circuit for an open or high resistance.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 4
CHECK THE REAR HEADLAMP LEVELING SENSOR
1. Turn the ignition off.
2. Replace the Rear Headlamp Leveling Sensor in accordance with the Service Information.
3. Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  Does this DTC reset after performing the Body Verification Test?
  
  Yes
  - Replace the Automatic Headlamp Leveling Module (AHLM) in accordance with the Service Information.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Test Complete
CHECK THE WIRING AND CONNECTORS
1. The conditions necessary to set the DTC are not present at this time.
2. Using the schematics as a guide, inspect the wiring and connectors specific to this module. Wiggle the wiring and connectors while checking for shorted and open circuits.
3. Check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
4. Check Service Bulletins for any possible causes that may apply.
  Were there any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Test complete.