Anti-Lock Brake System: Operation

ECU receives AC signal from each wheel sensor. The ECU computes wheel speed and determines correct deceleration speed of vehicle. When ECU determines that wheel lock-up is about to occur, it activates the solenoid valves to control hydraulic fluid to each wheel. This prevents wheel lock-up. System will cycle 4-10 times per second.

Fig 1: ABS Component Locations

Courtesy of AUSTIN ROVER GROUP.