Antilock Brakes / Traction Control Systems: Description and Operation

The Anti-Lock Brake System was designed to enhance braking performance by reducing vehicle speed in the shortest distance possible under limited traction conditions. This is accomplished by using sensors at both front wheels and one in the differential to send wheel speed information to an electronic control unit. If the electronic control unit detects any wheel slip while braking, it sends signals to the hydraulic unit to control the brake pressure in that braking circuit.
The system components include wheel speed sensors, toothed rings, a hydraulic modulator, an Electronic Control Unit (ECU), brake switch, driver warning lamps, and the fuses, connectors and wiring associated with supporting the components. In addition, the anti-lock system uses a conventional master cylinder, power booster, and calipers located in the usual position.