B1681

B1681-REAR HEADLAMP LEVELING SENSOR CIRCUIT PERFORMANCE





For a complete wiring diagram, refer to the Wiring Information.

- When Monitored:
Continuously.

- Set Condition:
The Automatic Headlamp Leveling Module (AHLM) detects the Headlamp Leveling Sensor Rear Signal circuit is out of range.





1. ACTIVE DTC
1. Ignition on, engine not running.
2. With the scan tool, record and erase DTCs.
3. Turn the headlamps on.
4. With the scan tool, read DTCs.

Is the status Active for this DTC?

Yes

- Go To 2

No

- Go To 12

2. (L962) HEADLAMP LEVELING SENSOR RETURN CIRCUIT SHORTED TO VOLTAGE




1. Turn the headlamps off.
2. Turn the ignition off to the lock position.
3. Disconnect the Rear Headlamp Level Sensor harness connector.
4. Disconnect the Right HIDL harness connector.
5. Ignition on, engine not running.
6. Measure the voltage between ground and the (L962) Headlamp Leveling Sensor Return circuit in the Right HIDL harness connector.

Is any there voltage present?

Yes

- Repair the (L962) Headlamp Leveling Sensor Return circuit for a short to voltage.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 3

3. (L961) HEADLAMP LEVELING SENSOR 5 VOLT SUPPLY CIRCUIT SHORTED TO VOLTAGE




1. Measure the voltage between ground and the (L961) Headlamp Leveling Sensor 5 Volt Supply circuit in the Right HIDL harness connector.

Is any there voltage present?

Yes

- Repair the (L961) Headlamp Leveling Sensor 5 Volt Supply circuit for a short to voltage.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 4

4. (L963) HEADLAMP LEVELING SENSOR REAR SIGNAL CIRCUIT SHORTED TO VOLTAGE




1. Measure the voltage between ground and the (L963) Headlamp Leveling Sensor Signal circuit in the Right HIDL harness connector.

Is any there voltage present?

Yes

- Repair the (L963) Headlamp Leveling Sensor Signal circuit for a short to voltage.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 5

5. (L962) HEADLAMP LEVELING SENSOR RETURN CIRCUIT SHORTED TO GROUND




1. Turn the ignition off to the lock position.
2. Measure the resistance between ground and the (L962) Headlamp Leveling Sensor Return circuit in the Right HIDL harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Repair the (L962) Headlamp Leveling Sensor Return circuit for a short to ground.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 6

6. (L961) HEADLAMP LEVELING SENSOR 5 VOLT SUPPLY CIRCUIT SHORTED TO GROUND




1. Measure the resistance between ground and the (L961) Headlamp Leveling Sensor 5 Volt Supply circuit in the Right HIDL harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Repair the (L961) Headlamp Leveling Sensor 5 Volt Supply circuit for a short to ground.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 7

7. (L963) HEADLAMP LEVELING SENSOR REAR SIGNAL CIRCUIT SHORTED TO GROUND




1. Measure the resistance between ground and the (L963) Headlamp Leveling Sensor Signal circuit in the Right HIDL harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Repair the (L963) Headlamp Leveling Sensor Signal circuit for a short to ground.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 8

8. (L962) HEADLAMP LEVELING SENSOR RETURN CIRCUIT OPEN OR HIGH RESISTANCE




1. Measure the resistance of the (L962) Headlamp Leveling Sensor Return circuit between the Rear Headlamp Level Sensor harness connector and the Right HIDL harness connector.

Is the resistance above 5.0 Ohms?

Yes

- Repair the (L962) Headlamp Leveling Sensor Return circuit for an open or high resistance.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 9

9. (L961) HEADLAMP LEVELING SENSOR 5 VOLT SUPPLY CIRCUIT OPEN OR HIGH RESISTANCE




1. Measure the resistance of the (L961) Headlamp Leveling Sensor 5 Volt Supply circuit between the Rear Headlamp Level Sensor harness connector and the Right HIDL harness connector.

Is the resistance above 5.0 Ohms?

Yes

- Repair the (L961) Headlamp Leveling Sensor 5 Volt Supply circuit for an open or high resistance.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 10

10. (L963) HEADLAMP LEVELING SENSOR REAR SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE




1. Measure the resistance of the (L963) Headlamp Leveling Sensor Signal circuit between the Rear Headlamp Level Sensor harness connector and the Right HIDL harness connector.

Is the resistance above 5.0 Ohms?

Yes

- Repair the (L963) Headlamp Leveling Sensor Signal circuit for an open or high resistance.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 11

11. REAR HEADLAMP LEVEL SENSOR
1. Replace the Rear Headlamp Level Sensor.Perform the BODY VERIFICATION TEST. Body Verification Test.
2. Ignition on, engine not running.
3. With the scan tool, erase DTCs.
4. Turn the headlamps on.
5. With the scan tool, read DTCs.

Does the DTC reset or is the status Active for this DTC?

Yes

- Replace the Automatic Headlamp Leveling Module (AHLM).
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Test Complete.

12. INTERMITTENT WIRING HARNESS AND CONNECTORS
1. The conditions necessary to set this DTC are not present at this time.
2. Using the schematics as a guide, inspect the wiring harness and connectors specific to this circuit.
3. Wiggle test the wiring harness and connectors while monitoring the scan tool data relative to this circuit.
4. Using the scan tool, monitor the data related to this circuit while performing the wiggle test. Look for the data to change or for the DTC to reset.

Were there any problems found?

Yes

- Repair as necessary.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Test Complete.