Anti-Lock Brake System: Operation

The Teves Anti-Lock Brake System (ABS) is activated during hard braking to prevent wheel lock-up. Wheel lock-up does not mean wheel has stopped, but wheel is turning slower than vehicle speed. When ignition is on, before vehicle is moved, Controller Anti-Lock Brake (CAB) performs a static system initialization. When vehicle speed reaches approximately 6 MPH, CAB briefly cycles pump to verify operation. Hydraulic Control Unit (HCU) solenoids are checked continuously.

When ABS is activated, vibrations and pulsations may be felt in brake pedal and solenoid valves clicking and pump motor running may be heard. Some wheel slip is required for best braking performance. This wheel slip may be heard as tire chirping. DO NOT  confuse tire chirping with tire skidding. When vehicle is braked heavily, wheels will lock-up below 3 MPH. When braking on rough road surfaces, ABS may activate detecting wheel lock-up tendencies from wheel hop.