Anti-Lock Brake System (ABS) Warning Indicator
WARNING: This page is about a different car, the 2004 Ford RV Cutaway, 2004 Ford Econoline, 2004 Ford E450 Super Duty, and 2004 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.
The instrument cluster receives status information from the ABS module through a hardwired circuit from the ABS module. When the ABS module detects a fault, it grounds the circuit, causing the ABS warning indicator to illuminate.