Park, License, and/or Tail Lamps Malfunction
Park, License, and/or Tail Lamps Malfunction
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
The park lamps and license plate lights are turned ON when the headlamp switch is placed in the parking lights or low beam position or anytime the headlights are requested. When the body control module (BCM) receives an request to switch ON the park lamps and license plate lights the BCM provides a sends out a PWM signal, which illuminates the park lamps and license plate lights.
Reference Information
Schematic Reference
Exterior Lights Schematics (Exterior Lights Schematics)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
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 (Programming and Relearning)for scan tool information
Circuit/System Verification
1. Switch the park lamps ON and OFF using the headlamp switch. Verify the scan tool Park Lamp Switch parameter cycles between Active and Inactive as commanded.
• If the parameter does not cycle between the specified values, refer to Park Lamp Switch Malfunction.
2. Ignition ON, switch ON and OFF the park lamps and license plate lights by using the headlamp switch. Park lamps and license plate lights should go ON and OFF.
• If the tail lamp are inoperative, refer to Tail Lamps Inoperative
• If the license plate lights are inoperative, refer to License Plate Lights Inoperative
Circuit/System Testing
Tail Lamps Inoperative
1. Ignition OFF, disconnect the harness connector at the appropriate inoperative tail lamp.
2. Disconnect the negative terminal of the C1 Battery.
3. Test for less than 5 ohm between the appropriate tail lamp ground circuit harness connector listed below and ground:
* E5AA Tail/Brake Lamp - Left harness connector terminal 3
* E5AB Tail/Brake Lamp - Right harness connector terminal 3
• If greater than the specified value, test the ground circuit for an open/high resistance.
4. Reconnect the negative terminal to the C1 Battery.
5. Connect a test lamp between the appropriate tail lamp control circuit harness connector listed below and ground:
* E5AA Tail/Brake Lamp - Left harness connector terminal 2
* E5AB Tail/Brake Lamp - Right harness connector terminal 2
6. Ignition ON, switch ON and OFF the tail lamps by using the headlamp switch. The test lamp should turn ON and OFF when changing between the ON/OFF states.
• If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K9 Body Control Module.
• If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuits test normal, replace the K9 Body Control Module.
7. If all the circuits test normal, replace the appropriate inoperative tail lamp.
License Plate Lights Inoperative
1. Ignition OFF, disconnect the harness connector at the E7 License Plate Lamp.
2. Disconnect the negative terminal of the C1 Battery.
3. Test for less than 5 ohm between the E7 License Plate Lamp ground circuit terminal 1 and ground.
• If greater than the specified value, test the ground circuit for an open/high resistance.
4. Reconnect the negative terminal to the C1 Battery.
5. Connect a test lamp between the E7 License Plate Lamp control circuit terminal 2 and ground.
6. Switch ON the parking lamps or low beam. The test lamp should be ON.
• If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K9 Body Control Module.
• If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuits test normal, replace the K9 Body Control Module.
7. If all the circuits test normal, replace the E7 License Plate Lamp.
Park Lamp Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the S30 Headlamp Switch.
2. Verify that a test lamp illuminates between the ground circuit terminal 6 and B+.
• If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
3. Ignition ON, test for B+ between the park lamp signal circuit terminal 3 and ground.
• If less than the specified value, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 Body Control Module.
4. Install a 3 A fused jumper wire between the park lamp ON signal circuit terminal 3 and ground. Verify the scan tool Parklamp Switch parameter changes from Inactive to Active.
• If always Inactive, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K9 Body Control Module.
• If always active, test the signal circuit for a short to ground. If the circuit tests normal, replace the K9 Body Control Module.
5. If all circuits test normal, replace the S30 Headlamp Switch.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Rear License Plate Lamp Replacement (Rear License Plate Lamp Replacement)
* Tail Lamp Replacement (Service and Repair)
* Tail Lamp Bulb Replacement (Service and Repair)
* Headlamp Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning)for BCM replacement, setup and programming