Anti-Lock Brake System: Operation
Each wheel sensor sends an AC electrical signal to the CM. The CM translates this information as wheel speed. When any decelerating wheel speed rate is determined to be excessive in comparison to other monitored wheels, the hydraulic unit cycles hydraulic brake pressure to vary brake fluid pressure to each wheel (4-channel on traction control equipped) or each front wheel and both rear wheels (3-channel on non-traction control equipped) to prevent wheel lock-up.
Pump motor will operate for a short period of time and may be heard inside vehicle. During pump motor operation, ABS system completes a self-check. During ABS system operation, brake pedal pulsation and steering wheel and vehicle body vibration may be experienced. These conditions are normal.
Optional Traction Control (TC) system uses engine control to control throttle, fuel and ignition systems to control wheel spin. TC system also uses ABS system for individual wheel braking to enhance wheel spin control.