Anti-Lock Brake System: Description

The Anti-Lock Brake System (ABS) consists of hydraulic unit, actuator, solenoids, pump motor, ABS Electronic Control Unit (ECU), relays and speed sensors. See Figure.

An ABS indicator light is located on the instrument cluster. Indicator light comes on for 3 seconds as a bulb test when ignition is turned on. A primary check is performed after each engine start and initial vehicle speed exceeds 4 MPH. An actuator noise is heard as vehicle speed exceeds 4 MPH, this is normal. If brake pedal is depressed before vehicle exceeds 4 MPH, the primary check will not occur until brake pedal is released.