Headlamp Leveling Malfunction (TR6)
Headlamp Leveling Malfunction (TR6)
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
Diagnostic Fault Information
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
Headlights/Daytime Running Lights (DRL) Schematics Headlights/Daytime Running Lights (DRL) Schematics
Connector End View Reference
Component Connector End Views Sunshade - Left (DH6)
Description and Operation
Exterior Lighting Systems Description and Operation Exterior Lighting Systems
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References 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
1. Ignition OFF, disconnect the harness connector at the appropriate inoperative headlamp assembly.
2. Disconnect the negative terminal of the C1 Battery.
3. Test for less than 5 ohms between the ground circuit terminal 7 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
4. Reconnect the negative terminal to the C1 Battery.
5. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 6 and ground. The test lamp should illuminate.
• If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
6. Ignition OFF, disconnect the harness connector at the S30 Headlamp Switch.
7. Ignition ON, connect a test lamp between the ignition circuit terminal 9 and ground. The test lamp should illuminate.
• If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
8. Test for less than 0.3 V between the signal circuit terminal 10 and ground.
• If greater than the specified range, test the signal circuit for a short to voltage.
9. Ignition OFF, install a 3 A fused jumper wire between the signal circuit terminal 10 and B+. Check fuse from jumper wire.
• If the fuse is blown, test the signal circuit for a short to ground.
10. Disconnect the 3 A fused jumper wire, test for less than 5 ohms between the signal circuit terminal 10 at the S30 Headlamp Switch and the control circuit terminal 8 at the appropriate headlamp assembly.
• If greater than the specified range, test the signal circuit for an open/high resistance.
11. Reconnect the harness connector at the S30 Headlamp Switch.
12. Ignition ON, test for 2.5-6.5 V between the control circuit terminal 8 at the appropriate headlamp assembly and ground. Switch the headlamp leveling switch in each position, the voltage should change in each position.
• If the voltage does not change, test or replace the S30 Headlamp Switch.
13. If all circuits test normal, replace the appropriate headlamp assembly.
Component Testing
Static Test
1. Ignition OFF, disconnect the harness connector at the S30 Headlamp Switch.
2. Switch the headlamp leveling switch in position 0. Test for 2.2-2.4 kohms between the ignition circuit terminal 9 and the signal terminal 10.
• If not within the specified range, replace the S30 Headlamp Switch.
3. Switch the headlamp leveling switch in position 1. Test for 1.9-2.2 kohms between the ignition circuit terminal 9 and the signal terminal 10.
• If not within the specified range, replace the S30 Headlamp Switch.
4. Switch the headlamp leveling switch in position 2. Test for 1.7-2.1 kohms between the ignition circuit terminal 9 and the signal terminal 10.
• If not within the specified range, replace the S30 Headlamp Switch.
5. Switch the headlamp leveling switch in position 3. Test for 1.4-1.6 kohms between the ignition circuit terminal 9 and the signal terminal 10.
• If not within the specified range, replace the S30 Headlamp Switch.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Headlamp Switch Replacement Service and Repair
* Headlamp Replacement (Left Side) Headlamp Replacement (Left Side)