Important: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Voltage for the courtesy lamps is supplied from the CTSY/RF Trim Fuse in the rear electrical center to the body control module (BCM). When a door is opened, a signal is applied to the door module. The door module then applies a message to the LAN communication circuit to the BCM. The BCM then applies voltage to the courtesy lamps voltage supply circuit. The courtesy lamps are composed of the following components:

The ignition is ON, and the BCM attempts to illuminate the courtesy lamps.

The BCM receives a ground signal on the courtesy lamp voltage supply circuit.

The BCM cease attempt to illuminate the courtesy lamps.

The BCM clears this code from current when the fault is removed from the system.

Schematic Reference

Interior Lights Schematics

Connector End View Reference

Lighting Systems Connector End Views

Electrical Information Reference

Scan Tool Reference

Ignition ON, cover the ambient light sensor, vary the interior lamp dimming switch from dim to full bright. The LED lamps should dim and then become full bright.

1. Disconnect all the courtesy lamps voltage supply circuit lamps related components. Refer to the circuit/system verification for all components that contain the courtesy lamps voltage supply circuit lamps. Verify the DTC B2615 does not set.

⇒	If the DTC resets, then test for a short to ground in the courtesy lamp voltage supply circuit lamps circuit. If the circuit/connections test normal, replace the BCM.

2. Reconnect each component one at a time and test for the DTC B2615. If the DTC resets, then replace that component.

Important: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.