What is Anti-Lock Brake Control Module (ABS)?
Anti-lock Brake Systems (ABS) operate as follows: When the brakes are applied, fluid is forced from the brake master cylinder outlet ports to the HCU inlet ports. This pressure is transmitted through four normally open solenoid valves contained inside the HCU, then through the outlet ports of the HCU to each wheel. The primary (rear) circuit of the brake master cylinder feeds the front brakes. The secondary (front) circuit of the brake master cylinder feeds the rear brakes. If the anti-lock brake control module senses a wheel is about to lock, based on anti-lock brake sensor data, it closes the normally open solenoid valve for that circuit. This prevents any more fluid from entering that circuit. The anti-lock brake control module then looks at the anti-lock brake sensor signal from the affected wheel again. If that wheel is still decelerating, it opens the solenoid valve for that circuit. Once the affected wheel comes back up to speed, the anti-lock brake control module returns the so
