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
Battery voltage is applied at all times to both the coil and switch sides of the PARK LAMP relay located in the underhood fuse block. The headlamp 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 T/LAMP LT and T/LAMP RT 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 1-2 Shift Solenoid (SS) Valve (MN5)
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
Ignition ON, observe the scan tool Parklamp Switch parameter while cycling the park lamp switch ON and OFF. The parameter should change between Active and Inactive.
If the parameter does not change between the commanded states, refer to Park Lamp Switch Malfunction.
If the parameter changes between the commanded 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 headlamp switch.
2. Ignition OFF, verify a test lamp illuminates between B+ and the ground circuit terminal 4.
• 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 2 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 2 and ground. Verify the scan tool Parklamp 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 headlamp switch.
Park, License, and/or Tail Lamps Malfunction
1. Ignition OFF, remove the fuse of the appropriate park/marker lamps and inspect.
• If the fuse is OPEN, test the control circuit of the blown fuse for a short to ground.
2. Install the fuse.
3. Ignition OFF, disconnect the park lamp relay.
4. Ignition ON, verify 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.
5. Verify 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.
6. Verify 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.
7. Disconnect the harness connector at the appropriate park/license/marker lamp.
8. Ignition OFF, exterior lamps OFF, test for less than 5 ohms between the ground circuit terminal and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
9. Connect the harness connector at the park/license/marker lamp.
10. Connect a 20A 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.
11. Connect a test lamp between the B+ circuit terminal 85 and the control circuit terminal 86.
12. 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.
13. If all circuits test normal, test or replace the park lamp relay.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Front Side Marker Lamp Replacement Front Side Marker Lamp Replacement
* Front Side Marker Lamp Bulb Replacement Front Side Marker Lamp Bulb Replacement
* Rear Side Marker Lamp Replacement Rear Side Marker Lamp Replacement
* Rear Side Marker Lamp Bulb Replacement Rear Side Marker Lamp Bulb Replacement
* Front Side Turn Signal Lamp Replacement Service and Repair
* Parking and Turn Signal Lamp Bulb Replacement Service and Repair
* Rear License Plate Lamp Replacement Service and Repair
* Tail Lamp Replacement Service and Repair
* Tail Lamp Bulb Replacement (Back Up and Turn Signal) Service and RepairTail Lamp Bulb Replacement (Stop Lamp) Service and Repair
* Relay Replacement (Within an Electrical Center) Relay Replacement (Within an Electrical Center)Relay Replacement (Attached to Wire Harness) Relay Replacement (Attached to Wire Harness)
* Headlamp Switch Replacement Service and Repair
* Control Module References Programming and Relearning for BCM replacement, setup, and programming