Park, License, and/or Tail Lamps Malfunction (North America)
Park, License, and/or Tail Lamps Malfunction (North America)
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
Battery positive voltage is applied at all times to both the coil and switch sides of the LT/POS/LP relay located in the rear fuse block. The turn signal/multifunction switch is suppled with ground at all times. When the headlamp switch is placed in either the HEAD or PARK position, ground is applied to the park lamp signal circuit to the body control module (BCM). The BCM responds by applying ground to the park lamp relay control circuit. This energizes the park lamp relay coil causing the relay switch contacts to close allowing battery voltage to flow through the LT/POS/LP and RT/POS/LP fuses to all of the park, tail, license, and marker lamps.
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
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
1. Ignition ON, observe the scan tool Parklamp Switch parameter while cycling the park lamp switch between the ON and OFF positions. The reading should toggle between Active and Inactive.
• If the reading does not change between the selected states, refer to Park Lamp Switch Malfunction.
2. Command the Parking Lamps ON and OFF with a scan tool. The park lamps should turn ON and OFF when changing between the commanded states.
• If any park lamps does not turn ON and OFF when commanded, refer to Park, License, and/or Tail Lamps Malfunction.
Circuit/System Testing
Park Lamp Switch Malfunction
1. Ignition OFF, disconnect the X1 harness connector at the turn signal/multifunction switch.
2. Ignition OFF, verify that a test lamp illuminates between B+ and the ground circuit terminal 9.
• If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool Parklamp Switch parameter is Inactive.
• If not the specified value, test the signal circuit terminal 6 for a short to ground. If the circuit tests normal, replace the BCM.
4. Install a 3 A fused jumper wire between the signal circuit terminal 6 and ground. Verify the scan tool Park Lamp 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 BCM.
5. If all circuits test normal, test or replace the turn signal/multifunction switch.
Park, License, and/or Tail Lamps Malfunction
1. Ignition OFF, disconnect the LT/POS/LP relay.
2. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 87 and ground.
• If the test lamp illuminates, test the control circuit for a short to voltage.
3. Verify that a test lamp illuminates between the B+ circuit terminal 30 and ground.
• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, test the control circuit terminal 87 for a short to ground. If the circuit tests normal, test or replace the park lamp relay.
4. Verify that a test lamp illuminates between the B+ circuit terminal 85 and ground.
• If the test lamp does not illuminate, test the B+ circuit for an open/high resistance.
5. Ignition OFF, disconnect the harness connector at the appropriate park/license/marker lamp.
6. Ignition OFF, exterior lamps OFF, test for less than 5 ohm between the ground circuit terminal listed below and ground:
* Marker Lamp - Terminal B
* Park Lamp - Front - Terminal B
* Tail Lamp - Terminal C
* License Lamp - Terminal 2
• If greater than the specified range, test the ground circuit for an open/high resistance.
7. Connect the harness connector at the park/license/marker lamp.
8. Connect a 10 A fused jumper wire between the B+ circuit terminal 30 and the control circuit terminal 87. Verify the park/license/marker lamps illuminate.
• If the park/license/marker lamps do not illuminate, test the control circuit for an open/high resistance. If the circuit tests normal, replace the park/license/marker lamp.
9. Connect a test lamp between the B+ circuit terminal 85 and the control circuit terminal 86.
10. Command the Parking Lamps ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
• If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM.
• If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
11. If all circuits test normal, test or replace the relay.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
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* Rear License Plate Lamp Replacement (Sedan, V-Series) Rear License Plate Lamp Replacement (Sedan, V-Series)Rear License Plate Lamp Replacement (Wagon) Rear License Plate Lamp Replacement (Wagon)Rear License Plate Lamp Replacement (Coupe) Rear License Plate Lamp Replacement (Coupe)
* Tail Lamp Replacement (Sedan, V-Series) Tail Lamp Replacement (Sedan, V-Series)Tail Lamp Replacement (Wagon) Tail Lamp Replacement (Wagon)Tail Lamp Replacement (Coupe) Tail Lamp Replacement (Coupe)
* Parking and Turn Signal Lamp Bulb Replacement Service and Repair
* Relay Replacement (Attached to Wire Harness) Relay Replacement (Attached to Wire Harness)Relay Replacement (Within an Electrical Center) Relay Replacement (Within an Electrical Center)
* Turn Signal Multifunction Switch Replacement Turn Signal Multifunction Switch Replacement
* Control Module References Control Module References for BCM replacement, setup, and programming