System Outline

If the brake pedal is depressed suddenly, the ABS controls the hydraulic pressure of all four wheel cylinders automatically to avoid wheel locking and ensure the directional and steering stability of the vehicle. If the brake pedal is depressed suddenly, the brake actuator assembly controls the solenoids in the actuators using the signals from the sensors to move the brake fluid from the cylinders to the reservoir in order to reduce the braking pressure. Also, If the brake actuator assembly detects that the fluid pressure in the wheel cylinder is insufficient, the ECU controls the solenoids in the actuators to increase the braking pressure.

The traction control system controls the engine torque, the hydraulic pressure of the driving wheel cylinders, and any wheel slippage which may occur during vehicle takeoff or acceleration of the vehicle. This is to ensure optimal driving power and vehicle stability corresponding to the road conditions.

Unexpected road conditions, vehicle speed, an emergency situation, and other external factors may cause excessive under or over steering of the vehicle. If this occurs, the VSC system automatically adjusts the engine power and wheel brakes to reduce the under or over steer.

To reduce over steering :

If the VSC system determines that the over steer is excessive, it activates the brakes for the outer turning wheels depending on the degree of the over steer to produce moment toward the outer side of the turn and reduce the over steer.

To reduce under steering :

If the VSC system determines that the under steer is excessive, it adjusts the engine power and activates the rear wheel brakes to reduce the under steer.

If an error occurs in the brake actuator assembly, sensor signals, and/or actuators, the brake actuator assembly inhibits the brake actuator control and sends an error signal to the ECM. According to the error signal, the brake actuator may turn off the solenoid at which time the ECM will reject any electronic throttle open requests from the VSC system. As a result, the vehicle continues to operate, but without the ABS, TRAC, and VSC systems.