The park, tail, marker, and license lamps are turned on when the headlamp switch is placed in the PARK or ON position or anytime the headlights are requested. The I/P BATT fuse in the engine wiring harness junction block supplies battery positive voltage to both the parklamp relay switch contacts and the parklamp coil circuit. The body control module (BCM) provides a ground or control circuit to the parklamp relay coil circuit. When the parklamps are turned on, the BCM energizes the parklamp relay. Current flow is from the parklamp relay to the individual parklamp circuit fuses and to their respective park, tail, marker, and license lamps. The front park and marker lamps are grounded at G107 and G103. The tail lamps are grounded at G401 and G402. The license lamps are grounded at G401. If the driver places the headlight switch in the ON position after the ignition switch has been turned OFF, the park, tail, marker, and license lamps will remain on until turned off or the battery runs dead.

Schematic Reference

Exterior Lights 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 parklamp switch parameter while cycling the headlamp switch between the Park and OFF positions. The parameter should cycle between Active and Inactive.

⇒	If the parameter does not cycle between the specified values, refer to Parklamp Switch Malfunction.

2. Command the Parking Lamps ON and OFF with a scan tool. Verify the park, license, and tail lamps turn ON and OFF.

⇒	If any of the lamps do not cycle between the commanded states, refer to Exterior Lamps Malfunction.

Parklamp Switch Malfunction

1. Ignition OFF, disconnect the harness connector X3 at the turn signal/multifunction switch.
2. Ignition OFF, test for less than 5.0 ohms between the ground circuit terminal K and ground.

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

3. Ignition ON, verify the scan tool BCM Parklamp Switch parameter is Inactive.

⇒	If not the specified value, test the signal circuit terminal M 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 M and ground. Verify the scan tool BCM Parklamp Switch parameter is Active.

⇒	If not the specified value, test the signal circuit for a short to voltage or open/high resistance. If the circuit tests normal, replace the BCM.

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

Exterior Lamps Malfunction

1. Ignition OFF, remove the fuse of the inoperative park/marker lamps and inspect.

⇒	If the fuse is OPEN, test the control circuit of the blown fuse for a short to ground.

2. Install the fuse.
3. Ignition OFF, disconnect the parklamp relay.
4. Verify that a test lamp does not illuminate when connected between the control circuit terminal 87 and ground.

⇒	If the test lamp illuminates, test the circuit for a short to voltage.

5. Verify that a test lamp illuminates between the parklamp relay B+ circuit terminal 85 and ground.

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

6. Verify that a test lamp illuminates between the parklamp relay B+ circuit terminal 30 and ground.

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

7. Ignition OFF, reconnect the parklamp relay.
8. Ignition OFF, disconnect the inoperative park, marker, or license lamp.
9. Ignition OFF, disconnect the inoperative park, marker, or license lamp bulb.
10. Test for less than 5.0 ohms of resistance on the listed ground circuit terminals and ground.

•	Front Park/Turn SIgnal Lamp terminal 3

•	Front Marker Lamp terminal B

•	License Lamp terminal B

•	Rear Marker Lamp terminal A

•	Tail/Stop Lamp terminal GRD

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

11. Ignition ON, connect a test lamp between the listed control circuit terminal and ground.

•	Front Park/Turn SIgnal Lamp terminal 2

•	Front Marker Lamp terminal A

•	License Lamp terminal A

•	Rear Marker Lamp terminal B

•	Tail/Stop Lamp terminal MNR

12. Turn the park lamp switch ON and OFF and verify that the test lamp turns ON and OFF.

⇒	If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance.

⇒	If the test lamp remains illuminated, test the control circuit for a short to voltage.

13. If all circuits test normal, replace the inoperative lamp.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.