Courtesy Lamp: Description and Operation

The Courtesy Lamps are controlled by the instrument cluster. The instrument cluster is sometimes referred to as a "Smart Cluster Control Module". Some of the features that it controls are the courtesy lamps, chime, and all instrument illumination. It receives and sends messages to other modules via the PCI bus circuit. The front turn signals are wired through the cluster and then go to the front lamps. For vehicles equipped with Daytime Running Lamps, the DRL module is built into the cluster.