Description

DESCRIPTION

The electronic anti-lock brake system (BOSCH 5.3 ABS) governs braking pressure sent to the wheels and prevents loss of grip under all tyre and road surface conditions.

The system is designed to complement the normal mechanical braking system and not to replace it. In this way it ensures effective safety in the case of anomalies: the ABS uses the same fluid as the conventional mechanical braking system.

Four sensors fitted to the four wheels inform the electronic control unit of wheel speed at every moment. In this way, they detect wheel lock, wheel slip and loss of grip.

Under these conditions, the control unit sends specific instructions to solenoids that modulate hydraulic circuit pressure to eliminate lock and restore the car to within grip limits. This ensures the shortest possible stopping distance, without losing control of the steering.

Two adjustment solenoids (one for pressure charging, the other for pressure discharging) are fitted for each wheel.

The 'active' type sensors consists of a Hall effect receiver facing a mangetic codifier incorporated in the hub bearing; under these circumstances the signal is less affected by electro-magnetic interference and by the temperature.

The control unit also controls brake force distribution over the rear axle and thus replaces the mechanical load proportioning valve used previously (EBD function: Electronic Brake Distribution).

The control unit is equipped with a self-diagnostic function: when an error occurs in the ABS system, the warning light is turned on and the system is simultaneously deactivated. Under these conditions, the car brakes using only the conventional system. Under these conditions, the car brakes using only the conventional system.

When the control unit detects an error in the EBD function, it simultaneously turns on the 'insufficient brake fluid level' and 'handbrake on' warning light as well as the ABS warning light.

Under these conditions, the rear brake distribution control is also deactivated and the car must be driven with great care.

The supply lines for the control unit and the various system components (sensors and actuators) are protected by a specific 60A maxifuse and fuse F3 (10A) located in the junction unit B1.