Antilock Brakes / Traction Control Systems: Description and Operation

The Anti-Lock Braking System (ABS) prevents wheels from locking up when braking, regardless of the surface conditions. This allows the vehicle to stop in a shorter distance, and allows the driver to maintain directional control of the vehicle during heavy braking.

During normal braking conditions, the ABS operates like a conventional diagonally split hydraulic power assist system. During heavy braking, however, each wheel's braking pressure is modulated according to its speed. To maintain stability, both rear wheels receive the same signal.












The ABS consists of wheel speed sensors, pedal stroke sensor, hydraulic unit and the ABS-ECU. If a problem occurs in the system, the malfunctioning system can be identified by means of the diagnostic function. The diagnostic trouble code will not be erased even if the ignition switch is turned to OFF.(However, it will be erased if the battery is disconnected.)

In addition, reading of diagnostic trouble codes, service data and actuator testing are possible using the scan tool.