Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

The courtesy lamp fuse supplies battery voltage to the body control module (BCM). The BCM applies battery voltage to the courtesy lamps through the courtesy lamp supply voltage circuit. The courtesy lamps are triggered by the door switch, a door lock/unlock command a momentary switch located next to the centre interior light. The lamps are controlled by the BCM. When any door is opened, the door switch contacts close sending the BCM a door-open input, or if the BCM receives a door lock or unlock input, the BCM will activate the courtesy lamp supply voltage circuit, providing battery voltage to the interior lights.

Battery voltage must be between 9-16 volts.

The BCM detects an open or short to voltage in the courtesy light control circuit.

When DTC B2555 is present, the courtesy lamps will only operate manually from the momentary switch.

Schematic Reference

Interior Lights Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

Scan Tool Reference

Control Module References

Ensure all the doors are closed, lock and unlock the doors. The courtesy lights should illuminate and deactivate as the doors are unlocked and locked.

1. Disconnect the courtesy lamp harness connector at the courtesy lamp.
2. Connect a test lamp between the courtesy lamp control circuit and a known ground at the courtesy harness connector.

⇒	Activate and deactivate the momentary switch the test lamp should illuminate and deactivate as the switch is operated.

⇒	If the test lamp does not illuminate and deactivate, with all doors closed, open and close the drivers door. The test lamp should illuminate and deactivate as the door is opened and closed.

⇒	If the test lamp does not illuminate and deactivate on either circuit, locate and repair an open/high resistance or short to voltage in the control circuit.

3. If circuits test OK, replace the BCM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM replacement, setup and programming.