Exterior Courtesy Lamps

WARNING: This page is about a different car, the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 Chevrolet Silverado, and 2002 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The SEO 1 15A fuse in the engine wiring harness junction block supplies battery positive voltage to both the exterior courtesy lamp relay switch contacts and the exterior courtesy lamp relay coil circuit. When the driver or passenger door is opened the body control module (BCM) energizes the exterior courtesy lamp relay. Current flow is from the exterior courtesy lamp relay to both outside rear view mirror exterior courtesy lamps. The exterior courtesy lamps are grounded at G200 and G203. When the remote function actuation (RFA) module receives a door unlock command from the remote function actuator transmitter, the RFA module will send a message to the body control module (BCM) indicating that an UNLOCK command has been received. The BCM must have inputs that indicate that the ignition switch is OFF, all the doors are closed. The BCM will activate the exterior courtesy lamp relay illuminating the power outside mirror exterior courtesy lamps. If the door locks are activated to the LOCK position, or if the ignition switch is turned to either the ON or RUN position the exterior courtesy lamps will deactivate immediately.

When an outside door handle is lifted or a door is opened, the exterior courtesy lamps illuminate.