Air Bag Warning Indicator
WARNING: This page is about a different car, the 2004 Ford Pickup, 2004 Ford F550 Super Duty, 2004 Ford F450 Super Duty, 2004 Ford Excursion, and 2004 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
The instrument cluster is hardwired to the restraint control module. If an air bag system DTC is detected, the restraint control module provides a ground path to the instrument cluster and the air bag indicator is illuminated.