Anti-Lock Brake System: Description

Anti-Lock Brake System (ABS) consists of hydraulic unit, actuator, solenoids, pump motor, ABS Electronic Control Unit (ECU), relays and wheel speed sensors. See Fig 1.

An ABS warning light is located in instrument cluster. ABS warning light illuminates for 3 seconds as a bulb test when ignition is turned on. A primary check is performed after each engine start and when initial vehicle speed exceeds 6 MPH. An actuator noise is heard as vehicle is started or as speed exceeds 6 MPH. This is normal operation.

Fig 1: Locating ABS Components

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002