### System Outline

1.ABS Operation

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

2.Traction Control Operation

The traction control system controls the engine torque, the hydraulic pressure of the driving wheel cylinders, slipping of the wheels which may occur at start or acceleration of the vehicle, to ensure an optimal driving power and vehicle stability corresponding to the road conditions.

3.VSC Operation

Unexpected road conditions, vehicle speed, emergency situation, and any other external factors may cause large under or oversteering of the vehicle. If this occurs, the VSC system automatically controls the engine power and wheel brakes to reduce the under or oversteering.

To reduce large oversteering :
If the VSC system determines that the oversteering is large, it activates the brakes for the outer turning wheels depending on the degree of the oversteering to produce the moment toward the outside of the vehicle and reduce the oversteering.

To reduce large understeering :
If the VSC system determines that the understeering is large, it controls the engine power and activates the rear wheel brakes to reduce the understeering.

4.Fail Safe Function

If an error occurs in the skid control ECU, sensor signals, and/or actuators, the skid control ECU inhibits the brake actuator control and inputs the error signal to the engine control module. According to the error signal, the brake actuator turns off the solenoid and the engine control module rejects any electronically controlled throttle open request from the VSC system. As a result, the vehicle functions regardless of the ABS, TRC, and VSC systems.

5.Downhill Assist Control Operation

The downhill assist control operation controls braking action of each wheel to help prevent outofbalance vehicle posture when descending a steep hill or traveling at a speed exceeding the threshold of wheel gripping capability. When the downhill assist control is in operation, the brake system control vehicles speed within the range of 5 to 7 km/h.

6.HillStart Assist Control Operation

When starting on a steep hill for ascending, the hillstart support control automatically puts the brake on momentarily from the moment when the driver releases his foot from the brake pedal until he steps on the accelerator pedal to help the driver start the vehicle safely and smoothly.
Please bear in mind, however, that it activates the brake system for only 3 seconds.