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 PARKING LIGHT 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 PWM signal, 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 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. Ignition ON, turn the park lamps ON and OFF using the S78 turn signal/multifunction 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 S78 turn signal/multifunction 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 Lamp Malfunction.
Circuit/System Testing
Park Lamp Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the S78 turn signal/multifunction 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 7 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 BCM.
4. Install a 3 A fused jumper wire between the park lamp ON signal circuit terminal 7 and ground. Verify the scan tool Park Lamps 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 BCM.
• If always Active, test the signal circuit for a short to ground. If the circuit tests normal, replace the K9 BCM.
5. If all circuits test normal, replace the S78 turn signal/multifunction switch.
Park, License and/or Tail Lamp Malfunction
1. Ignition OFF, disconnect the harness connector at the appropriate park, license and/or tail lamp.
2. Test for less than 5 ohm between the ground circuit terminal listed below and ground:
* E2 Side Marker Lamp - Terminal B
* E4 Park/Turn Signal Lamp - Terminal G
* E5 Tail/Turn Signal Lamp - Terminal G
* 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:
* E2 Side Marker Lamp - Terminal A
* E4 Park/Turn Signal Lamp - Terminal B
* E5 Tail/Turn Signal Lamp - Terminal B
* E7 License Plate Lamp - Terminal 1
4. Turn the park, license and tail lamps ON and OFF using the S78 turn signal/multifunction 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, license and/or tail lamp.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Rear License Plate Lamp Replacement (Equinox) (Service and Repair)Rear License Plate Lamp Replacement (Terrain) (Service and Repair)
* Headlamp Replacement (Equinox) (Removal and Replacement)Headlamp Replacement (Terrain) (Removal and Replacement)
* Turn Signal Multifunction Switch Replacement (Turn Signal Multifunction Switch Replacement)
* Tail Lamp Replacement (Equinox) (Tail Lamp Replacement)Tail Lamp Replacement (Terrain) (Tail Lamp Replacement)
* Control Module References (Programming and Relearning) for BCM replacement, setup, and programming