Circuit Description

CIRCUIT DESCRIPTION

ABS

The Anti-Lock Brake System (ABS) controls the hydraulic brake pressure of all four wheels during sudden braking and braking on hazardous road surfaces, preventing the wheels from locking. The ABS provides the following benefits:

1. Enables steering around obstacles with a greater degree of certainty during panic braking.
2. Enables stopping during panic braking while allowing stability and control even on curves.In case a malfunction occurs in the anti-lock brake system, the system will operate as a normal brake system (fail-safe mode). A diagnosis function and fail-safe system have been included for serviceability.

EBD (Electronic brake-force Distribution)

The EBD portion of the ABS system replaces the proportioning valves in a conventional brake system. By modulating fluid pressure to the rear brakes, The EBD systems prevents the rear wheels from locking up prematurely.

1. Function improvement of base-brake system.
2. Compensation of different friction coefficients.
3. Elimination of proportioning valve.
4. Failure recognition by warning lamp. See section BRa of the shop manual for a complete diagnosis of the anti-lock brake system (ABS).


TCS

The traction control is a variable system designed to enhance traction during acceleration and cornering. It does so by determining the optimum amount of wheel spin for any given driving situation, then suppressing surplus engine power accordingly.

The ABS control module gets signals about the vehicle's speed, direction and road conditions from sensors at the wheels and the steering column. Based on these signals, The control module will determine the optimum amount of wheel spin. Because the system is variable, the control unit may determine, depending on the driving conditions, that some wheel spin is beneficial (thus enhancing straight-line acceleration), or that no wheel spin is beneficial(thus enhancing cornering). For any given driving situation, the control module will determine the amount of wheel spin best suited to the driver's needs. The system is automatically ready whenever the engine is started, but can be manually canceled with the TCS switch. The TCS provides the following benefits.

1. When the drive wheel speed exceeds the vehicle speed by a given amount, the ABS control module judges that the drive wheels are slipping, and it outputs the traction control signal to reduce engine power.
2. Based on signals from the wheel sensor, the control module detects a rough road based on frequency of wheel rotational vibration. The control module signals the TCS control valve actuator and ECM to relax engine power, thus improving acceleration efficiency.
3. Based on signals about wheel speed, the control module determines the effciency of the grip of the tires on the road and signals the TCS control valve actuator and the ECM relaxes engine power if necessary, thus improving grip.