Feature

FEATURE
The ABS/TCS is a system into which both the functions of the anti-lock brake system (ABS) and the traction control system (TCS) are integrated.

The main control systems of the ABS/TCS are as follows:

ABS:
Front wheels are controlled independently and rear wheels are done simultaneously (select low control) by the 4-sensor 4-channel control system.

TCS:
Engine control Number of cylinders into which fuel is injected is controlled (fuel cut system).
Brake control Driving wheels (front wheels) are independently controlled.

a. Outline of ABS control
The ABS control system detects respective revolution speeds of four wheels with the wheel speed sensors (ABS sensors).

When a wheel is about to be locked, the solenoid valve is activated to release (decreases) braking pressure of the wheel cylinder to the reservoir of the master cylinder to prevent the wheel from getting locked. For pressurizing, fluid pressure of the master cylinder's pressure chamber is applied to the wheel cylinder. At that time, the stroke sensor monitors the amount of the brake pedal stroke, and if it exceeds the specific amount, the motor pump is activated to make pressure feed of brake fluid to the pressure chamber from the reservoir of the master cylinder in order to prevent stamping on the brake pedal to the floor. The solenoid valve control is so simple that it is just turned on and oft.

b. Outline of TCS control
The TCS control is activated when either of driving wheels is slipping, that is, a calculation result that wheel speeds of the driving wheels and non-driving wheels are compared by the ABS/TCS control module exceeds the threshold value. There are two kinds of the threshold values, one is for engine control and the other is for brake control.

This TCS employs two control systems of the normal control and the control focused on acceleration. When two driving wheels slip, the control system regards it as caused by over output of the engine torque and controls engine output by reducing fuel injected cylinders in number in addition to brake control to decrease excess torque (normal control). On the other hand, when one of driving wheels slips, the control system restores the engine torque in addition to brake control (control focused on acceleration).