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 |
|---|---|---|---|---|
Ignition Headlamp Switch | 1 | 1 | -- | -- |
Ignition Left Headlamp | 1 | 2 | -- | -- |
Ignition Right Headlamp | 1 | 3 | -- | -- |
Left Headlamp Leveling Control | 1 | 2 | 1 | -- |
Right Headlamp Leveling Control | 1 | 3 | 1 | -- |
Left Headlamp Ground | -- | 2 | -- | -- |
Right Headlamp Ground | -- | 3 | -- | -- |
1. All Headlamp Leveling Actuator Malfunction 2. Left Headlamp Leveling Actuator Malfunction 3. Right Headlamp Leveling Actuator Malfunction | ||||
Circuit/System Description
Each headlamp assembly contains a headlamp leveling motor that is controlled by the headlight switch. The headlight switch is a resistance ladder switch and wired to each headlamp leveling motor. With the ignition in ON position the headlight switch and each headlamp leveling motor is applied to B+. Each headlamp leveling motor is permanently grounded.
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, cycle the headlamp leveling switch in each position while observing both headlamps. Both headlamps should operate to the appropriate position when commanded.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the appropriate headlamp assembly.
- Ignition OFF, test for less than 5 Ω between the ground circuit terminal 3 and ground.
- Ignition ON, connect a test lamp between the ignition circuit terminal 1 and ground. The test lamp should illuminate.
- Ignition OFF, disconnect the harness connector at the S30 Headlamp Switch.
- Ignition ON, connect a test lamp between the ignition circuit terminal 9 and ground. The test lamp should illuminate.
- Ignition ON, test for less than 0.3 V between the signal circuit terminal 10 and ground.
- Ignition OFF, test for greater than 500 kΩ between the signal circuit terminal 10 and ground.
- Ignition OFF, test for less than 5 Ω between the signal circuit terminal 10 at the S30 Headlamp Switch and the control circuit terminal 2 at the appropriate headlamp assembly.
- Ignition OFF, reconnect the harness connector at the S30 Headlamp Switch. Connect a test lamp between the control circuit terminal 2 at the appropriate headlamp assembly and ground.
- Switch the headlamp leveling switch in each position. The test lamp illumination should change in each position.
- If all circuits test normal, replace the appropriate headlamp assembly.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. |
| ⇒ | If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. |
| ⇒ | If greater than the specified range, test the signal circuit for a short to voltage. |
| ⇒ | If less than the specified range, test the signal circuit for a short to ground. |
| ⇒ | If greater than the specified range, test the signal circuit for an open/high resistance. |
| ⇒ | If the test lamp does not illuminate or does not change their illumination, replace the S30 Headlamp Switch. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
