Anti-Lock Braking System (ABS)

General information

Vehicles are fitted with an anti-lock braking system (ABS) by Teves. The anti-lock braking system prevents the wheels from locking during heavy braking. Thanks to this, the car remains under control even when braking fully. The ABS is ready for operation when the ignition is switched on and the control lamp goes out. RPM sensors measure wheel speed. Based on the signals from the sensors, the electronic control unit calculates the speed of the vehicle. By comparing the speed of an individual wheel with the average speed of the vehicle, the control unit determines the wheel lock condition and can determine when the wheel starts to lock.

The rear wheels do not have sensors. The braking performance of the rear wheels is controlled by the front wheels. To prevent the rear wheels from locking under all braking conditions, each rear brake circuit has a load-dependent pressure regulator that determines the braking force of the rear wheels. When the front wheel approaches blocking, the brake fluid pressure is too high, so the pressure in the caliper is reduced by the signal from the control unit. This happens until the wheel starts to accelerate again.

Then the valves close again and the pressure created by the brake pedal starts to act again. However, the pressure in the brake system is not higher than the total pressure in the system. ABS operation during heavy braking is repeated on each wheel until pedal force is applied or the vehicle stops. When the vehicle speed is less than 7 km/h, ABS does not work. In the event of any malfunction in the ABS system, it is disabled. In this case, the ABS warning lamp in the instrument cluster comes on and the braking system operates normally. If one of the brake circuits fails, the other circuit continues to be controlled by the ABS.

Attention. When carrying out electric welding, disconnect the connector from the control unit with the ignition off. The ABS control unit is located at the rear left of the engine compartment. Any checks and adjustments of the ABS system should be carried out at a service station.