Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Headlamp Leveling Module B+ | 1 | 1 | -- | -- |
Suspension Position Sensor - Front Voltage Reference | B3410 02, 2 | B3410 03, 2 | B3410 07, 2 | -- |
Suspension Position Sensor - Rear Voltage Reference | B3420 02, 3 | B3420 03, 3 | B3420 07, 3 | -- |
Suspension Position Sensor - Front Signal | B3410 02, 2 | B3410 03, 2 | B3410 07, 2 | -- |
Suspension Position Sensor - Rear Signal | B3420 02, 3 | B3420 03, 3 | B3420 07, 3 | -- |
Headlamp Leveling Motor (1) Control - Left | B2667 02 | B2667 05 | B2667 05 | -- |
Headlamp Leveling Motor (2) Control - Left | B2672 02 | B2672 05 | B2672 05 | -- |
Headlamp Leveling Motor (3) Control - Left | B1457 02 | B1457 05 | B1457 05 | -- |
Headlamp Leveling Motor (4) Control - Left | B1458 02 | B1458 05 | B1458 05 | -- |
Headlamp Leveling Motor (1) Control - Right | B2677 02 | B2677 05 | B2677 05 | -- |
Headlamp Leveling Motor (2) Control - Right | B2682 02 | B2682 05 | B2682 05 | -- |
Headlamp Leveling Motor (3) Control - Right | B1459 02 | B1459 05 | B1459 05 | -- |
Headlamp Leveling Motor (4) Control - Right | B1460 02 | B1460 05 | B1460 05 | -- |
Headlamp Leveling Motor - Left Low Reference | -- | 1 | -- | -- |
Headlamp Leveling Motor - Right Low Reference | -- | 1 | -- | -- |
Suspension Position Sensor - Front Low Reference | -- | 2 | -- | -- |
Suspension Position Sensor - Rear Low Reference | -- | 3 | -- | -- |
Headlamp Leveling Actuator - Left Ground | -- | 1 | -- | -- |
Headlamp Leveling Actuator - Right Ground | -- | 1 | -- | -- |
Headlamp Leveling Module Ground | -- | 1 | -- | -- |
1. Headlamp Leveling Malfunction 2. Suspension Position Sensor Malfunction - Front 3. Suspension Position Sensor Malfunction - Rear | ||||
Circuit/System Description
The headlamp leveling module receives inputs from the front and rear suspension position sensors to determine vehicle pitch. The suspension position sensors send an output to the headlamp leveling module as the vehicle suspension compresses and rebounds. The headlamp leveling module calculates the difference in vehicle pitch and sends a command to the headlamp leveling actuators. The headlamp leveling actuators drive the headlamps to the position commanded by the headlamp leveling module. The headlamp leveling module monitors the headlamp leveling actuator motor control circuits for proper circuit continuity and for shorts to ground or voltage. If a malfunction is detected, a DTC will be stored in memory.
Diagnostic Aids
When one of the suspension position sensor voltage reference or sensor signal circuits are shorted to ground, it may not be possible to determine which suspension position sensor voltage reference or sensor signal circuits, front or rear, has failed. If this condition occurs, all suspension position sensor voltage reference and sensor signal circuits will have to be tested for a short to ground.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Exterior Lighting Systems Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Ignition ON, with a scan tool perform the Headlamp Motor Test and observe the headlamps. Both headlamps should move UP and DOWN as the test is performed.
| ⇒ | If both head lamps do not move UP and DOWN when commanded, refer to Headlamp Leveling Actuator Malfunction. |
| ⇒ | If both head lamps move UP and DOWN when commanded, refer to Suspension Position Sensor Malfunction. |
Circuit/System Testing
Headlamp Leveling Actuator Malfunction
- Ignition OFF, disconnect the harness connector at the headlamp leveling module.
- Ignition OFF, scan tool OFF, exterior lamps OFF, test for less than 5 ohms between the ground circuit terminal 24 and ground.
- Ignition ON, test for B+ between the voltage circuit terminal 12 and ground.
- Ignition OFF, connect the headlamp leveling control module harness connector.
- Disconnect the harness connector at the inoperative headlamp leveling actuator.
- Ignition ON, verify that a test lamp illuminates between the low reference circuit terminal 2 and B+.
- Ignition OFF, connect a test lamp between the control circuit terminal 1 and the low reference circuit terminal 2.
- Ignition ON, headlamps ON, perform the Headlamp Motor Test with a scan tool. The test lamp should turn ON then OFF as the motor test is performed.
- Ignition OFF, connect a test lamp between the control circuit terminal 3 and the low reference circuit terminal 2.
- Ignition ON, headlamps ON, perform the Headlamp Motor Test with a scan tool. The test lamp should turn ON then OFF as the motor test is performed.
- Ignition OFF, connect a test lamp between the control circuit terminal 4 and the low reference circuit terminal 2.
- Ignition ON, headlamps ON, perform the Headlamp Motor Test with a scan tool. The test lamp should turn ON then OFF as the motor test is performed.
- Ignition OFF, connect a test lamp between the control circuit terminal 6 and the low reference circuit terminal 2.
- Ignition ON, headlamps ON, perform the Headlamp Motor Test with a scan tool. The test lamp should turn ON then OFF as the motor test is performed.
- If all circuits test normal, replace the inoperative headlamp leveling actuator.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If less than the specified range, test the voltage circuit for a short to ground or an open/high resistance. |
| ⇒ | If the test lamp does not illuminate, test the low reference circuit for a short to voltage or and open/high resistance. If the circuit tests normal, replace the headlamp leveling module. |
| ⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the headlamp leveling module. |
| ⇒ | If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the headlamp leveling module. |
| ⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the headlamp leveling module. |
| ⇒ | If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the headlamp leveling module. |
| ⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the headlamp leveling module. |
| ⇒ | If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the headlamp leveling module. |
| ⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the headlamp leveling module. |
| ⇒ | If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the headlamp leveling module. |
Suspension Position Sensor Malfunction - Front
- Ignition OFF, disconnect the harness connector at the LF suspension position sensor.
- Ignition OFF, verify that a test lamp illuminates between B+ and the low reference circuit terminal C.
- Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal A and ground.
- Verify the scan tool Front Leveling Position Sensor parameter is less than 0.5 volts.
- Install a 3A fused jumper wire between the signal circuit terminal B and the 5-volt reference circuit terminal A. Verify the scan tool Front Leveling Position Sensor parameter is greater than 4.49 volts.
- If all circuits test normal, test or replace the LF suspension position sensor.
| ⇒ | If the test lamp does not illuminate, test the low reference circuit for an open/high resistance. |
| ⇒ | If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the headlamp leveling module. |
| ⇒ | If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the headlamp leveling module. |
| ⇒ | If greater than the specified range, test the signal circuit terminal B for a short to voltage. If the circuit tests normal, replace the headlamp leveling module. |
| ⇒ | If less than the specified range, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the headlamp leveling module. |
Suspension Position Sensor Malfunction - Rear
- Ignition OFF, disconnect the harness connector at the LR suspension position sensor.
- Ignition OFF, verify that a test lamp illuminates between B+ and the low reference circuit terminal C.
- Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal A and ground.
- Verify the scan tool Rear Leveling Position Sensor parameter is less than 0.5 volts.
- Install a 3A fused jumper wire between the signal circuit terminal B and the 5-volt reference circuit terminal A. Verify the scan tool Rear Leveling Position Sensor parameter is greater than 4.49 volts.
- If all circuits test normal, test or replace the LR suspension position sensor.
| ⇒ | If the test lamp does not illuminate, test the low reference circuit for an open/high resistance. |
| ⇒ | If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the headlamp leveling module. |
| ⇒ | If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the headlamp leveling module. |
| ⇒ | If greater than the specified range, test the signal circuit terminal B for a short to voltage. If the circuit tests normal, replace the headlamp leveling module. |
| ⇒ | If less than the specified range, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the headlamp leveling module. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for headlamp leveling module replacement, setup, and programming |
