Renault Megane, Scenic

Since 1996 of release

Repair and car operation

The general description of system of antiblocking of brakes (ABS)

Models with the expanded complete set are equipped ABS. The system consists of the hydraulic block and four gauges on wheels. The hydraulic block includes the electronic control mean, eight hydraulic electromagnetic valves (on two for each brake - entrance and target) and the electropump. The system purpose - to prevent blocking of a wheel during sharp braking. As soon as one of wheels close to blocking, the system automatically disconnects the given brake mechanism and when blocking threat passes, will involve it again. In case of back wheels both brakes are applied simultaneously.
Electromagnetic valves cope the electronic block which receives signals from four gauges of speed of rotation of wheels (are attached to naves). Comparing these signals, the management block defines, what of wheels has slowed down rotation and is close to blocking. The block sends a signal to corresponding valve and pressure of a brake liquid in the given brake knot decreases. In a usual mode the system works also, as brake system without ABS.
If speed of rotation of a wheel continues to decrease, the management block opens the entrance valve of the given brake and includes the returnable pump which pumps out a part of a brake liquid from a brake contour back in the main cylinder. As soon as speed of rotation of a wheel comes back to norm, the pump is disconnected; the electromagnetic valve opens, and the brake is again applied. This cycle can repeat many times in a second.
Work of electromagnetic valves and the returnable pump creates impulses in a hydrowire. When system ABS functions, these impulses are felt on a brake pedal.
System ABS action completely depends on electric signals. To prevent reaction of system to extraneous signals, the contour of safety supervising all impulses is built in it, received by the electronic block. If such signal is found out or pressure of the accumulator low, system ABS is automatically disconnected, and on the instrument panel the control lamp lights up.
If in system ABS there was a malfunction, address on HUNDRED.