B+ is applied at all times to the park lamp relay. When the headlamp switch is placed in either the PARK or HEAD position, ground is applied through the park lamp switch on signal circuit to the body control module (BCM). The BCM then applies a ground to the park lamp relay control circuit. This energizes the relay and applies voltage through the park/license lamps.

Schematic Reference

Headlights/Daytime Running Lights (DRL) Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Exterior Lighting Systems Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for Scan Tool Information

1. Ignition ON, observe the scan tool Park Lamp Switch parameter while cycling the headlamp switch between the PARK and OFF positions. The parameter should change between On and Off.

⇒	If the parameter does not change between the specified values, refer to Park Lamp Switch Circuit Malfunction.

2. Command the Parking Lamps ON and OFF with a scan tool. The park and license lamps should turn ON and OFF when changing between the commanded states.

⇒	If all the lamps are inoperative, refer to Park Lamp Relay Circuit Malfunction.

⇒	If one or more of the front park lamps are inoperative, refer to Front Park Lamp Circuit Malfunction.

⇒	If one or more of the rear park lamps are inoperative, refer to Rear Park Lamp Circuit Malfunction.

⇒	If one or more of the license lamps are inoperative, refer to License Lamp Circuit Malfunction.

Park Lamp Switch Circuit Malfunction

1. Ignition OFF, disconnect the harness connector at the headlamp switch.
2. Test for less than 10 ohms of resistance between the ground circuit terminal 17 and ground.

⇒	If the test lamp does not illuminate, test the ground circuit for an open/high resistance.

3. Ignition ON, verify the scan tool Park Lamp Switch parameter is Off.

⇒	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 3A fused jumper wire between the signal circuit terminal 6 and ground. Verify the scan tool Park Lamp Switch parameter is On.

⇒	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 Lamp Relay Circuit Malfunction

1. Ignition OFF, disconnect the PRK/LAMP relay.
2. Ignition ON, verify a test lamp illuminates between the B+ circuit terminal N1 and ground.

⇒	If the test lamp does not illuminate, test the control circuit terminal N3 for a short to ground. If the circuit tests normal, test or replace the I/P fuse block.

3. Verify a test lamp illuminates between the B+ circuit terminal M1 and ground.

⇒	If the test lamp does not illuminate, test or replace the I/P fuse block.

4. Install a test lamp between the B+ circuit terminal M1 and the control circuit terminal M3.
5. 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 terminal M3 for a short to ground. If the circuit tests normal, replace the BCM.

⇒	If the test lamp is always OFF, test the control circuit terminal M3 for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.

6. Ignition OFF, connect the PRK/LAMP relay. Disconnect the harness connector at the left tail lamp.
7. Install a test lamp between the control circuit terminal A and ground.
8. Ignition ON, command the Parking Lamps ON with a scan tool. The test lamp should illuminate.

⇒	If the test lamp does not illuminate, test or replace the PRK/LAMP relay.

9. If all circuits test normal, test or replace the I/P fuse block.

Front Park Lamp Circuit Malfunction

1. Ignition OFF, disconnect the harness connector at the inoperative park lamp bulb.
2. Test for less than 10 ohms of resistance between the appropriate ground circuit terminal and ground:

•	Marker Lamp - Ground circuit terminal B

•	Park/Turn Signal Lamp - Ground circuit terminal C

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

3. Install a test lamp between the appropriate control circuit terminal and ground:

•	Marker Lamp - Control circuit terminal A

•	Park/Turn Signal Lamp - Control circuit terminal B

4. Ignition ON, 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 voltage. If the circuit tests normal, test or replace the I/P fuse block.

⇒	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, test or replace the I/P fuse block.

5. If all circuits test normal, test or replace the appropriate park lamp bulb.

Rear Park Lamp Circuit Malfunction

1. Ignition OFF, disconnect the harness connector at the inoperative park lamp bulb.
2. Test for less than 10 ohms of resistance between the appropriate ground circuit terminal and ground:

•	Marker Lamp - Ground circuit terminal B

•	Tail/Stop and Turn Signal Lamp - Ground circuit terminal G

•	Tail Lamp Upper or Lower - Ground circuit terminal B

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

3. Install a test lamp between the appropriate control circuit terminal and ground:

•	Marker Lamp - Control circuit terminal A

•	Tail/Stop and Turn Signal Lamp - Control circuit terminal B

•	Tail Lamp Upper or Lower - Control circuit terminal A

4. Ignition ON, 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 voltage. If the circuit tests normal, test or replace the I/P fuse block.

⇒	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, test or replace the I/P fuse block.

5. If all circuits test normal, test or replace the appropriate park lamp bulb.

License Lamp Circuit Malfunction

1. Ignition OFF, disconnect the harness connector at the inoperative license lamp bulb.
2. Test for less than 10 ohms of resistance between the ground circuit terminal B and ground:

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

3. Install a test lamp between the control circuit terminal A and ground:
4. Ignition ON, 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 voltage. If the circuit tests normal, test or replace the I/P fuse block.

⇒	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, test or replace the I/P fuse block.

5. If all circuits test normal, test or replace the appropriate license lamp bulb.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.