Anti-lock Brake System (ABS) Warning Indicator
WARNING: This page is about a different car, the 2003 Ford RV Cutaway, 2003 Ford Econoline, 2003 Ford E550 Super Duty, 2003 Ford E450 Super Duty, and 2003 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.
The ABS warning indicator receives its ground from the ABS module when a malfunction is detected in the ABS system. The ABS warning indicator prove-out is in the RUN position and is controlled by the ABS module.