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, tail lamps and license plate lights are turned ON when the headlamp switch is placed in the PARK or LOW BEAM position or anytime the headlights are requested. When the body control module (BCM) receives a request from the headlamp switch to turn ON the park lamps the BCM a sends out a voltage on the control circuit, which illuminates the park lamps, tail lamps and license plate lights.
Reference Information
Schematic Reference
Exterior Lights Schematics (Exterior Lights Schematics)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Exterior Lighting Systems Description and Operation (Exterior Lighting Systems Description and Operation)
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. Ignition ON, turn the park lamps ON and OFF using the headlamp switch. The scan tool Park Lamps Switch parameter should cycle between Active and Inactive when changing between the selected states.
• If the parameter does not cycle between the selected states, refer to Park Lamp Switch Malfunction.
2. Turn the park, license plate and tail lamps ON and OFF using the headlamp switch. The park, license plate and tail lamps should turn ON and OFF when changing between the selected states.
• If any park, license plate or tail lamp does not turn ON and OFF when changing between the selected states, refer to Park, License, and/or Tail Lamps Malfunction.
Circuit/System Testing
Park Lamp Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the S30 headlamp switch.
2. Ignition OFF, verify that a test lamp illuminates between B+ and the ground circuit terminal 6.
• If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool Park Lamps Switch parameter is Inactive.
• If not the specified value, test the signal circuit terminal 3 for a short to ground. If the circuit tests normal, replace the K9 BCM.
4. Install a 3 A fused jumper wire between the signal circuit terminal 3 and ground. Verify the scan tool Park Lamps Switch parameter is Active.
• If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K9 BCM.
5. If all circuits test normal, test or replace the S30 headlamp switch.
Park, License, and/or Tail Lamps Malfunction
1. Ignition OFF, disconnect the harness connector at the appropriate park lamp.
2. Test for less than 5 ohm between the ground circuit terminal listed below and ground:
* E13 headlamp - terminal 1
* E42 tail lamp assembly - terminal F
* E7 license plate lamp - terminal 2
• If greater than the specified value, test the ground circuit for an open/high resistance.
3. Connect a test lamp between the control circuit terminal listed below and ground:
* E13 headlamp - terminal 4
* E42 tail lamp assembly - terminal C
* E7 license plate lamp - terminal 1
4. Turn the park lamps ON and OFF by using the S30 headlamp switch. The test lamp should turn ON and OFF when changing between the selected 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 BCM.
• 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 K9 BCM.
5. If all circuits test normal, test or replace the park lamp.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Headlamp Replacement (Headlamp Replacement)
* Tail Lamp Replacement (Service and Repair)
* Rear License Plate Lamp Replacement (Service and Repair)
* Headlamp Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for BCM replacement, setup and programming