Antilock Brakes / Traction Control Systems: Description and Operation

GENERAL DESCRIPTION





The ABS consists of components such as the wheel speed sensors, stoplight switch, hydraulic unit assembly (integrated with ABS-ECU) and the ABS warning light. If a problem occurs in the system, the malfunctioning components can be identified and the trouble symptoms will be memorized by the diagnostic function.
The system has the EBD (Electronic Brake-force Distribution) control system which provides the ideal braking force for the rear wheels. In addition, reading of diagnostic trouble codes and data list and actuator testing are possible by using the Scan Tool.

EBD CONTROL
In ABS, electronic control method is used whereby the rear wheel brake hydraulic pressure during braking is regulated by rear wheel control solenoid valves in accordance with the vehicle's rate of deceleration and the front and rear wheel slippage which are calculated from the signals received from the various wheel sensors. EBD control is a control system which provides a high level of control for both vehicle braking force and vehicle stability. The system has the following features:
- Because the system provides the optimum rear wheel braking force regardless of the vehicle laden condition and the condition of the road surface, the system reduces the required pedal depression force, particularly when the vehicle is heavily laden or driving on road surfaces with high frictional coefficients.
- Because the duty placed on the front brakes has been reduced, the increases in pad temperature can be controlled during front brakes applying to improve the wear resistance characteristics of the pad.
- Control valves such as the proportioning valve are no longer required.





CONSTRUCTION DIAGRAM