Headlamp Switch
WARNING: This page is about a different car, the 2003 Dodge Grand Caravan, 2003 Dodge Caravan, 2003 Chrysler Voyager, and 2003 Chrysler Town & Country. However, it is still accessible from the selected car via links, so may be relevant.
The Headlamp Switch uses a multiplexed (MUX) circuit to the Body Control Module (BCM). The Headlamp Switch controls the Fog lamp relay, Park lamps and the Low and High headlamps. The BCM then sends a signal through the PCI Bus line to the FCM as to what state the switch has selected. The FCM energizes the high side output drivers to turn ON the desired lamps.