Extended models are equipped with ABS. The system consists of a hydraulic unit and four sensors on wheels. The hydraulic unit includes an electronic control device, eight hydraulic solenoid valves (two for each brake - input and output) and electric pump. The purpose of the system is to prevent the wheel from locking up during heavy braking. As soon as one of the wheels is close to blocking, the system automatically disables this brake mechanism, and when the threat of blocking has passed, it activates it again. In the case of the rear wheels, both brakes are applied simultaneously.
The solenoid valves are controlled by an electronic unit that receives signals from four wheel speed sensors (attached to the hubs). By comparing these signals, the control unit determines which of the wheels has slowed down and is close to blocking. The block sends a signal to the corresponding valve and the pressure of the brake fluid in this brake assembly decreases. In normal mode, the system works in the same way as a non-ABS braking system.
If wheel speed continues to decrease, the control unit opens the inlet valve for that brake and turns on the return pump, which pumps some of the brake fluid out of the brake circuit back into the master cylinder. As soon as the wheel speed returns to normal, the pump is switched off; the solenoid valve opens and the brake is applied again. This cycle can repeat many times per second.
The operation of the solenoid valves and the return pump creates impulses in the hydraulic line. When the ABS system is functioning, these impulses are felt on the brake pedal.
The operation of the ABS system is completely dependent on electrical signals. To prevent the system from responding to extraneous signals, a safety circuit is built into it, which controls all impulses received by the electronic unit. If such a signal is detected or the battery voltage is low, the ABS system will automatically disengage and the warning lamp on the instrument panel will illuminate.
If there is a malfunction in the ABS system, contact a service station.