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
When the headlamp switch is placed in the HEAD or PARK position, ground is applied to the park lamp switch ON signal circuit to the body control module (BCM). The BCM responds by applying voltage to the park lamps, tail lamps, and license lamps control circuits illuminating the park, tail, and license lamps.
Reference Information
Schematic Reference
Exterior Lights Schematics Exterior Lights Schematics
Connector End View Reference
Component Connector End Views Sunshade - Left
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.
2. Verify the scan tool Park Lamp Switch parameter changes between Active and Inactive while commanding the park lamps ON and OFF with the turn signal/multifunction switch.
• If the parameter does not change
Refer to Headlamp Switch Malfunction.
• If the parameter changes
3. Verify the left park lamps turn ON and OFF when commanding the Left Park Lamps ON and OFF with a scan tool.
• If the left park lamps do not turn ON and OFF
Refer to Park Lamps Malfunction.
• If the left park lamps turn ON and OFF
4. Verify the right park lamps turn ON and OFF when commanding the Right Park Lamps ON and OFF with a scan tool.
• If the right park lamps do not turn ON and OFF
Refer to Park Lamps Malfunction.
• If the right park lamps turn ON and OFF
5. Verify the license plate lamps turn ON and OFF when commanding the License Plate Lamps ON and OFF with a scan tool.
• If the license plate lamps do not turn ON and OFF
Refer to License Plate Lamps Malfunction.
• If the license plate lamps turn ON and OFF
6. All OK.
Circuit/System Testing
Headlamp Switch Malfunction
1. Ignition OFF, all doors closed, all accessories OFF, disconnect the harness connector at the S30 headlamp switch. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 15 ohms between the ground circuit terminal 6 and ground.
• If 15 ohms or greater
1. Ignition OFF.
2. Test for less than 2 ohms in the ground circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.
• If less than 15 ohms
3. Ignition ON.
4. Verify the scan tool Park Lamps Switch parameter is Inactive.
• If not Inactive
1. Ignition OFF, disconnect the X1 harness connector at the K9 body control module.
2. Test for infinite resistance between the signal circuit terminal 3 and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the K9 body control module.
• If Inactive
5. Install a 3 A fused jumper wire between the signal circuit terminal 3 and the ground circuit terminal 6.
6. Verify the scan tool Park Lamps Switch parameter is Active.
• If not Active
1. Ignition OFF, disconnect the X1 harness connector at the K9 body control module, ignition ON.
2. Test for less than 1 V between the signal circuit terminal 3 and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V
3. Test for less than 2 ohms in the signal circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K9 body control module.
• If Active
7. Test or replace the S30 headlamp switch.
Park Lamps Malfunction
1. Ignition OFF, exterior lamps OFF, trunk latch latched, disconnect the harness connector at the inoperative park/marker/tail lamp.
2. Test for less than 5 ohms between the appropriate ground circuit terminal listed below and ground.
* E4N park/turn signal lamp - left terminal 2 (with T4A)
* E2LF side marker lamp - left front terminal 1 (with T4A)
* E13L headlamp - left terminal 1 (with T4F)
* E5AK tail lamp - left outer terminal 3
* E5G tail lamp - left inner terminal 2
* E4P park/turn signal lamp - right terminal 2 (with T4A)
* E2RF side marker lamp - right front terminal 1 (with T4A)
* E13R headlamp - right terminal 1 (with T4F)
* E5AL tail lamp - right outer terminal 3
* E5H tail lamp - right inner terminal 2
• If 5 ohms or greater
1. Ignition OFF.
2. Test for less than 2 ohms in the ground circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.
• If less than 5 ohms
3. Connect a test lamp between the appropriate control circuit terminal listed below and ground, ignition ON.
* E4N park/turn signal lamp - left terminal 3 (with T4A)
* E2LF side marker lamp - left front terminal 2 (with T4A)
* E13L headlamp - left terminal 7 (with T4F)
* E5AK tail lamp - left outer terminal 1
* E5G tail lamp - left inner terminal 3
* E4P park/turn signal lamp - right terminal 3 (with T4A)
* E2RF side marker lamp - right front terminal 2 (with T4A)
* E13R headlamp - right terminal 7 (with T4F)
* E5AL tail lamp - right outer terminal 1
* E5H tail lamp - right inner terminal 3
4. Verify the test lamp turns ON and OFF when commanding the appropriate Park Lamps ON and OFF with a scan tool.
• If the test lamp is always OFF
1. Ignition OFF, disconnect the X4 harness connector at the K9 body control module.
2. Test for infinite resistance between the control circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 ohms in the control circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K9 body control module.
• If the test lamp is always ON
1. Ignition OFF, disconnect the X4 harness connector at the K9 body control module, ignition ON.
2. Test for less than 1 V between the control circuit terminal and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K9 body control module.
• If the test lamp turns ON and OFF
5. Test or replace the appropriate park/marker/tail lamp.
License Plate Lamps Malfunction
1. Ignition OFF, exterior lamps OFF, remove both E7 license plate lamp bulbs.
2. Test for less than 5 ohms between the ground circuit terminal 2 and ground.
• If 5 ohms or greater
1. Ignition OFF.
2. Test for less than 2 ohms in the ground circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.
• If less than 5 ohms
3. Connect a test lamp between the license plate lamp - left control circuit terminal 1 and ground, ignition ON.
4. Verify the test lamp turns ON and OFF when commanding the License Plate Lamps ON and OFF with a scan tool.
• If the test lamp is always OFF
1. Ignition OFF, disconnect the X4 harness connector at the K9 body control module.
2. Test for infinite resistance between the control circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 ohms in the control circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K9 body control module.
• If the test lamp is always ON
1. Ignition OFF, disconnect the X4 harness connector at the K9 body control module, ignition ON.
2. Test for less than 1 V between the control circuit terminal and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K9 body control module.
• If the test lamp turns ON and OFF
5. Connect a test lamp between the license plate lamp - right control circuit terminal 1 and ground, ignition ON.
6. Verify the test lamp turns ON and OFF when commanding the License Plate Lamps ON and OFF with a scan tool.
• If the test lamp is always OFF
1. Ignition OFF, disconnect the X4 harness connector at the K9 body control module.
2. Test for infinite resistance between the control circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 ohms in the control circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K9 body control module.
• If the test lamp turns ON and OFF
7. Test or replace the appropriate E7 license plate lamp bulb.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Headlamp Switch Replacement Service and Repair
* Headlamp Replacement Headlamp Replacement
* Rear License Plate Lamp Replacement Rear License Plate Lamp Replacement
* Tail Lamp Replacement Service and Repair
* Tail Lamp Bulb Replacement Service and Repair
* Rear License Plate Lamp Bulb Replacement Rear License Plate Lamp Bulb Replacement
* Front Side Marker Lamp Bulb Replacement Service and Repair
* Control Module References Control Module References for BCM replacement, programming, and setup