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 and panel dimmer 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 voltage to the park lamps, tail lamps, and license lamps control circuits illuminating the park, tail, side marker, and license lamps.
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, observe the scan tool Parking Lamp Switch parameter while cycling the park lamp between the OFF and Park positions. The parameter should toggle between Active and Inactive.
• If the readings do not change between the commanded 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 the park lamps do not turn ON and OFF when commanded, refer to Park, License, and/or Tail Lamps Malfunction.
3. Command the Parking Lamps ON and OFF with a scan tool. The license plate lamps should turn ON and OFF when changing between the commanded states.
• If the license plate lamps do not turn ON and OFF when commanded, refer to License Plate Lamps Malfunction.
Circuit/System Testing
Park Lamp Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the S30 headlamp switch.
2. Ignition OFF, test for less than 5 ohm between the ground circuit terminal 6 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool Park Lamp Switch parameter is Inactive.
• If not the specified value, test the signal circuit terminal 3 for a short to ground. If the circuit tests normal, replace the K9 BCM.
4. Install a 3 A fused jumper wire between the signal circuit terminal 3 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 K9 BCM.
5. If all circuits test normal, test or replace the S30 headlamp switch.
Park, Marker, and/or Tail Lamps Malfunction
1. Ignition OFF, Disconnect the harness connector at the appropriate park lamp.
2. Ignition OFF, exterior lamps OFF, test for less than 5 ohm between the ground circuit terminal listed below and ground.
* E4 Park/Turn Signal Lamp - terminal 1
* E4 Front Park Lamp - terminal A
* E5 Tail/Stop and Turn Signal Lamp - terminal 1
* E2 Side Marker Lamp - terminal 2
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Connect a test lamp between the control circuit terminal listed below and ground.
* E4 Park/Turn Signal Lamp - terminal 2
* E4 Front Park Lamp - terminal D
* E5 Tail/Stop and Turn Signal Lamp - terminal 2
* E2 Side Marker Lamp - terminal 1
4. Command the appropriate park lamp test 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 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 lamp.
License Plate Lamps Malfunction
1. Ignition OFF, disconnect the harness connector at the appropriate E7 license plate lamp.
2. Ignition OFF, exterior lamps OFF, test for less than 5 ohm between the ground circuit terminal 2 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Connect a test lamp between the control circuit terminal 1 and ground.
4. Turn the license plate lamps ON and OFF with the parklamp 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 E7 license plate lamp.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Rear License Plate Lamp Replacement (Service and Repair)
* Front Side Marker Lamp Replacement (Front Side Marker Lamp Replacement)
* Rear Side Marker Lamp Replacement (Rear Side Marker Lamp Replacement)
* Tail Lamp Replacement - Inboard (Tail Lamp Replacement - Inboard)
* Tail Lamp Replacement - Outboard (Tail Lamp Replacement - Outboard)
* Headlamp, Instrument Panel Lamp Dimmer, and Fog Lamp Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for BCM replacement, setup, and programming