Park Lamps Malfunction

Park Lamps Malfunction

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Circuit/System Description

The park, tail, and marker lamps, including the license lamps, are turned ON when the headlamp switch is placed in the PARK or HEADLAMP position, or anytime the headlights are requested. The PARK LAMPS fuse in the rear fuse block supplies battery positive voltage to the PARK LAMP relay switch contacts. The PARK LAMPS fuse in the rear fuse block also supplies battery positive voltage to the PARK LAMP relay coil. When the park lamps are turned ON, the body control module (BCM) energizes the park lamp relay. Current flow is from the PARK LAMP relay to their respective park and marker lamps and to ground. Ground is provided at G101, G102, G401, and G403.

Circuit/System Verification

1. Ignition ON, command the park lamps ON and OFF with a scan tool. The park lamps should illuminate when commanded ON.

^ If the park lamps do not illuminate, refer to Park Lamps Inoperative From BCM.
^ If the park lamps are always illuminated, refer to Park Lamps Always On From Relay.

2. Refer to Park Lamps Inoperative From Switch.

Circuit/System Testing

Park Lamps Inoperative From BCM
1. Ignition OFF, disconnect the X1 harness connector at the BCM.
2. Ignition ON, install a 3A fused jumper wire between the park lamp relay control circuit terminal 8 and ground. Verify the park lamps illuminate.

^ If the park lamps do not illuminate, test the relay control circuit terminal 8 for a short to voltage or an open/high resistance. If the circuit tests normal, replace the underhood fuse block.

3. If all circuits test normal, replace the BCM.

Park Lamps Always On From Relay
1. Ignition OFF, disconnect the X1 harness connector at the BCM.
2. Ignition ON, verify that a test lamp does not illuminate between the park lamp relay control circuit terminal 8 and B+.

^ If the test lamp illuminates, test the control circuit terminal 8 for a short to ground.

3. Verify that the park lamps are not illuminated.

^ If the park lamps are illuminated, test the park lamp supply voltage circuit for a short to voltage. If the circuit tests normal, replace the underhood fuse block.

4. If all circuits test normal, replace the BCM.

Park Lamps Inoperative From Switch
1. Disconnect the X1 harness connector at the turn signal/multifunction switch.
2. Install a 3A fused jumper wire between the park lamp switch 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 terminal 3 for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.

3. Test the signal circuit terminal 3 for a short to ground. If all circuits test normal, replace the turn signal/multifunction switch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

* Underhood Electrical Center or Junction Block Bracket Replacement
* Turn Signal Multifunction Switch Replacement