Battery voltage is applied at all times to the coil and switch sides of the PARK LAMP Relay located in the underhood fuse block. Ground is applied at G201 to the turn signal/multifunction switch at all times. When the headlamp switch is placed in either the HEAD or PARK position, ground is applied to the park lamp switch signal circuit to the body control module (BCM). The BCM reacts to the signal from the park lamp switch by applying ground to the park lamp relay control circuit. This energizes the PARK LAMP Relay and applies battery voltage to the PARK LPS fuse. Voltage flows through the PARK LPS fuse to all park, tail, license, and side marker lamps. Ground for the front park and side marker lamps is supplied at G101 for the left and G102 for the right. Ground for the license and right rear tail lamps is supplied at G402, and the left rear tail lamps at G400.

Schematic Reference

Exterior Lights Schematics

Connector End View Reference

Lighting Systems Connector End Views

Electrical Information Reference

Scan Tool Reference

Park Lamps Inoperative - One

1. Ignition OFF, disconnect the inoperative park lamp harness connector.
2. Connect a test lamp between the park lamp voltage supply circuit and ground.
3. Ignition ON, turn ON the park lamps. The test lamp should illuminate.

⇒	If the test lamp does not illuminate, repair the inoperative park lamp voltage supply circuit for a short to ground or an open/high resistance.

4. Verify that a test lamp illuminates between the inoperative park lamp voltage supply circuit and the inoperative park lamp ground circuit.

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

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

Park Lamps Inoperative - All

1. Ignition OFF, disconnect the park lamp relay.
2. Connect a 15-amp fused jumper between the park lamp relay switch side voltage supply circuit and the park lamps voltage supply circuit at the underhood fuse block relay terminals. The park lamps should illuminate.

⇒	If the park lamps do not illuminate, repair the park lamps voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the underhood fuse block.

3. Connect a test lamp between the park lamp relay control circuit and the park lamp relay coil side supply voltage circuit at the underhood fuse block relay terminals.
4. Ignition ON, install a scan tool and command the park lamps ON. The test lamp should illuminate.

⇒	If the test lamp does not illuminate, repair the park lamp relay control circuit for a short to voltage or and open/high resistance. If the circuit tests normal, replace the BCM.

5. Connect the park lamp relay.
6. With a scan tool command the park lamp ON. The park lamps should illuminate.

⇒	If the park lamps do not illuminate, test or replace the park lamp relay.

7. Ignition OFF, disconnect the C1 harness connector at the turn signal/multifunction switch.
8. Connect a 3-amp fused jumper between the park lamp switch signal circuit and ground. The test lamp should illuminate.

⇒	If the test lamp does not illuminate, repair the park lamp switch signal circuit for an open/high resistance. If the circuit tests normal, replace the BCM.

9. Connect a 3-amp fused jumper between the park lamp switch signal circuit and the park lamp switch ground circuit at the turn signal/multifunction switch harness connector. The test lamp should illuminate.

⇒	If the test lamp does not illuminate, repair the park lamp switch ground circuit at the turn signal/multifunction switch for an open/high resistance.

10. If all circuits test normal, replace the turn signal/multifunction switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.