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 Switch Bit 1 Signal - Front | B3410 00, 1 | B3410 00, 1 | B3410 00, 1 | -- |
Headlamp Leveling Switch Bit 1 Signal - Rear | B3420 00, 1 | B3420 00, 1 | B3420 00, 1 | -- |
Headlamp Leveling Actuator - Left Control | B3420 00, 1 | B3420 00, 1 | B3420 00, 1 | -- |
Headlamp Leveling Actuator - Right Control | B3410 00, 1 | B3410 00, 1 | B3410 00, 1 | -- |
Headlamp Leveling Sensor - Front Control | B3410 00, 1 | B3410 00, 1 | B3410 00, 1 | -- |
Headlamp Leveling Sensor - Rear Control | B3420 00, 1 | B3420 00, 1 | B3420 00, 1 | -- |
Headlamp Leveling Actuator- Left Ground | -- | 1 | -- | -- |
Headlamp Leveling Actuator - Right Ground | -- | 1 | -- | -- |
Headlamp Leveling Sensor - Front Ground | -- | 1 | -- | -- |
Headlamp Leveling Sensor - Rear Ground | -- | 1 | -- | -- |
1. Headlamp Leveling Malfunction | ||||
Circuit/System Description
The front suspension position sensor provides the headlamp leveling modules with front suspension position information. The sensor is permanently grounded and has voltage supplied with the ignition in the ON or CRANK position. The sensor arm is connected to the control arm of the front suspension. As the vehicle travels, the suspension compresses and rebounds moving the suspension position sensor arm. This causes the signal output of the sensor to change. The headlamp leveling modules compare this information with the rear suspension position sensor information and adjusts the headlamp leveling as needed.
Diagnostic Aids
Important: 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 for the left and right headlamp leveling modules. The headlamp should move Up and Down as the test is performed.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the inoperative headlamp assembly.
- Ignition OFF, scan tool OFF, exterior lamps OFF, test for less than 5.0 ohms between the ground circuit terminal M and ground.
- Ignition ON, test for B+ between the B+ circuit terminal H and ground.
- If all circuits test normal, replace the inoperative headlamp assembly.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If less than the specified range, test the B+ circuit for a short to ground or an open/high resistance. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for headlamp leveling module replacement, setup, and programming |
