Anti-Lock Brake System: Operation

Under normal driving conditions, the anti-lock brake system functions as a standard brake system. With detection of impending rear wheel lock-up, the control unit modulates hydraulic pressure to the rear brakes to prevent lock-up.

With detection of wheel lock-up, short pedal pulsations, occurring in rapid succession, will be felt in brake pedal and steering wheel. Vehicle body may also vibrate slightly. These conditions are normal. Pedal pulsation will continue until there is no longer a need for anti-lock function or until vehicle is stopped.

ABS system can be diagnosed using a volt-ohmmeter and ABS warning light on instrument panel. When a malfunction is detected, the ABS control unit will hold a code in memory. If ABS warning light stays on or flashes after engine has been started, it indicates a code is present.