Anti-Lock Brake System: Description
CAUTION:
See ANTI-LOCK BRAKE SAFETY PRECAUTIONS article in GENERAL INFORMATION.
Anti-Lock Brake System (ABS) consists of hydraulic unit, solenoids, pump motor, ABS actuator, ABS control unit assembly, relays, and wheel speed sensors. ABS actuator is integrated with ABS control unit. See Fig 1.
An ABS warning light is located in instrument cluster. ABS actuator/control unit assembly performs a bulb test by illuminating ABS warning light for 3 seconds when ignition is turned on.
A primary check is performed after each engine start, and when initial vehicle speed exceeds 6 MPH. Under normal operation, an actuator noise is heard as vehicle is started or as speed exceeds 6 MPH. ABS remains active until vehicle speed drops to less than 3 MPH.