Description & Operation

NOTE: Mazda did not manufacture a 1999 MPV. Mazda MPV was redesigned and brought back in 2000 as a front wheel drive vehicle.

The Anti-Lock Brake System Control Module (ABS CM) senses reductions in front and rear wheel speed and modulates hydraulic pressure to the brakes to prevent wheel lock-up. The ABS consists of a hydraulic unit, 4 wheel speed sensors and sensor rotors and ABS CM. See Fig 1 . An ABS warning light is located on instrument cluster.

NOTE: For more information on base brake system, see DISC & DRUM - EXCEPT B2500, B3000, B4000 & MIATA for 2000 models and refer to DISC & DRUM for 2001 models.

Fig 1: Locating ABS Components

Courtesy of MAZDA MOTORS CORP.

Under normal driving conditions, ABS functions like a standard brake system. When vehicle speed reaches 3.8 MPH, ABS will diagnose pump motor by briefly operating motor. Pump motor operation may be heard inside vehicle.

ABS CM controls ABS by detecting speed sensor signals and activating solenoid valve in hydraulic unit. ABS CM also controls pump motor and self-diagnostic function. If a problem is detected in ABS, ABS will function like a conventional brake system. ABS warning light will also come on.

With detection of wheel lock-up, short pedal pulsations occur in rapid succession and 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 ABS function or until vehicle is stopped.