Anti-lock Brake Systems (ABS) enhance vehicle maneuverability, directional stability, and optimal deceleration during severe braking on various road surfaces by monitoring wheel rotational speed and controlling brake line pressure to prevent wheel lock-up on slippery roads or during hard braking. The hydraulic modulator/motor pack assembly, located on the side of the master cylinder, regulates hydraulic pressure to the front calipers and rear wheel cylinders or calipers to prevent lock-up. The Electronic Brake Control Module (EBCM), positioned under the left side of the dash in models through 1998 and integrated into the motor/modulator assembly in later models, oversees the ABS system and manages the anti-lock valve solenoids by processing information from the brake switch and wheel speed sensors. Each sensor assembly features a variable reluctance sensor and a toothed ring, with the air gap between them being non-adjustable and the sensors non-rebuildable; any malfunction necessitates replacement. A wheel speed sensor generates an AC voltage signal proportional to wheel speed as the toothed ring rotates, and the EBCM activates the ABS system upon detecting sudden wheel deceleration. The ABS system includes self-diagnostic capabilities, with warning lights on the instrument panel: a red BRAKE light indicating issues with the main braking system, an amber ABS light signaling ABS system problems, and a blue LOW TRAC light. Preliminary checks that can be performed by a home mechanic include inspecting 
Brake Calipers, checking the electrical connector at the controller, verifying fuses, and ensuring secure connections and undamaged wiring to the speed sensors and 
Brake Light Switch; if issues persist, professional diagnosis is recommended.