System Outline

* ABS system

This system controls the brake fluid pressures acting on the brake cylinders of the right front wheel, left front wheel, and rear wheels when the brakes are suddenly, to prevent the wheels from locking.

This results in improved directional stability and steerability during sudden braking.

* Front and rear braking force distribution system

Using a hydraulic control device, this system distributes the braking force to the front and rear wheels according to the running conditions of the vehicle.

1. Input Signals 
   1. Speed sensor signal

      The speed of the wheels is detected and input to TERMINALS 5, 7, 10 and 19 of the skid control ECU with actuator.

   2. Stop light SW signal

   A signal is input to TERMINAL 20 of the skid control ECU with actuator when the brake pedal is depressed.

2. System Operation 

During sudden braking the skid control ECU with actuator, which receives signals from all of the speed sensors, controls the current to the solenoid inside the actuator to allow some of the hydraulic pressure acting on each wheel cylinder escape to the reservoir. The pump inside the actuator also activates at this time and it returns brake fluid from the reservoir to the master cylinder, thus preventing the wheels from locking.

If the skid control ECU with actuator determines that the hydraulic pressure acting on the wheel cylinders is insufficient, the current to the solenoid is adjusted and the hydraulic pressure is increased. The hydraulic pressure can also be held at a fixed level by the skid control ECU with actuator, using the same method as above, by repeated pressure reductions and/or increases. Holding, reducing and increasing operations are repeated as required to maintain the vehicle stability and to improve steerability during sudden braking.