Antilock Brakes / Traction Control Systems: Description and Operation

The Anti-Lock Brake system (ABS) functions by releasing and applying fluid pressure to the front and rear brakes during special braking conditions. The ABS does not function under normal braking conditions, nor does it affect front-to-rear brake proportioning. When one or more wheels approach a slip condition, the ABS automatically senses the slip and activates the pressure control function.

Through its preprogramming, the ABS control module decides which wheel(s)' brake pressure needs modulation. Once determined, the control module sends appropriate signals to the solenoid valves located in the hydraulic anti-lock actuator assembly. These solenoid valves allow adjoining flow control valves to modulate fluid pressure, resulting in a pressure reduction at the front and rear brakes to prevent further lock-up.