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 turn signal/multifunction switch is placed in the HEAD or PARK position, ground is applied to the park lamps 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
* Body Control System Schematics [1][2]Body Control Systems
Connector End View Reference
Component Connector End Views Hybrid/EV Battery Pack X1
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. Vehicle in Service Mode.
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 Park Lamp Switch Malfunction.
• If the parameter changes
3. Verify the left front park lamp turns ON and OFF when commanding the Left Front Park Lamp ON and OFF with a scan tool.
• If the left front park lamp does not turn ON and OFF
Refer to Park Lamps Malfunction.
• If the left front park lamp turns ON and OFF
4. Verify the left rear park lamp turns ON and OFF when commanding the Left Rear Park Lamp ON and OFF with a scan tool.
• If the left rear park lamp does not turn ON and OFF
Refer to Park Lamps Malfunction.
• If the left rear park lamp turns ON and OFF
5. Verify the right front park lamp turns ON and OFF when commanding the Right Front Park ON and OFF with a scan tool.
• If the right front park lamp does not turn ON and OFF
Refer to Park Lamps Malfunction.
• If the right front park lamp turns ON and OFF
6. Verify the right rear park lamp turns ON and OFF when commanding the Right Rear Park ON and OFF with a scan tool.
• If the right rear park lamp does not turn ON and OFF
Refer to Park Lamps Malfunction.
• If the right rear park lamp turns ON and OFF
7. 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
8. All OK.
Circuit/System Testing
Park Lamp Switch Malfunction
1. Vehicle OFF, all doors closed, all accessories OFF, disconnect the harness connector at the S78 turn signal/multifunction switch. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 ohms between the ground circuit terminal 6 and ground.
• If 10 ohms or greater
1. Vehicle 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 10 ohms
3. Vehicle in Service Mode.
4. Verify the scan tool Park Lamps Switch parameter is Inactive.
• If not Inactive
1. Vehicle OFF, disconnect the X1 harness connector at the K9 body control module.
2. Test for infinite resistance between the signal circuit terminal 7 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 7 and the ground circuit terminal 6.
6. Verify the scan tool Park Lamps Switch parameter is Active.
• If not Active
1. Vehicle OFF, disconnect the X1 harness connector at the K9 body control module, vehicle in Service Mode.
2. Test for less than 1 V between the signal circuit terminal 7 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 S78 turn signal/multifunction switch.
Park Lamps Malfunction
1. Vehicle OFF, exterior lamps OFF, disconnect the harness connector at the inoperative E4 park 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 1
* E4P park/turn signal lamp - right terminal 1
* E42L tail lamp assembly - left terminal 4
* E42R tail lamp assembly - right terminal 4
• If 5 ohms or greater
1. Vehicle 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, vehicle in Service Mode.
* E4N park/turn signal lamp - left terminal 2
* E4P park/turn signal lamp - right terminal 2
* E42L tail lamp assembly - left terminal 2
* E42R tail lamp assembly - right terminal 2
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. Vehicle OFF, disconnect the appropriate harness connector listed below at the K9 body control module.
* X4
* X5
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. Vehicle OFF, disconnect the appropriate harness connector listed below at the K9 body control module, vehicle in Service Mode.
* X4
* X5
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 E4 park lamp.
License Plate Lamps Malfunction
1. Vehicle OFF, exterior lamps OFF, remove both E7 license plate lamp bulbs.
2. Test for less than 5 ohms between each ground circuit terminal 2 and ground.
• If 5 ohms or greater
1. Vehicle 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 E7L license plate lamp - left control circuit terminal 1 and ground, vehicle in Service Mode.
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. Vehicle 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. Vehicle OFF, disconnect the X4 harness connector at the K9 body control module, vehicle in Service Mode.
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 E7R license plate lamp - right control circuit terminal 1 and ground, vehicle in Service Mode.
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. Vehicle 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 Replacement Removal and Replacement
* Rear License Plate Lamp Replacement Rear License Plate Lamp Replacement
* Tail Lamp Replacement Tail Lamp Replacement
* Turn Signal Multifunction Switch Replacement Turn Signal Multifunction Switch Replacement
* Control Module References Programming and Relearning for BCM replacement, programming, and setup