11:24. System of anti-blocking of brakes (ABS) - the general information, failure diagnostics and codes of malfunctions

General information

When the vehicle is equipped with the brake system of usual type, sharp squeezing of a pedal of a foot brake leads to blocking of wheels. At the same time coupling of a protector with a paving is broken, and the car can start to skid, losing controllability. The system of anti-blocking of brakes (ABS) prevents premature blocking of wheels, continuously operating the speed of their rotation during braking due to modulations of pressure of hydraulic liquid in each of brake mechanisms.

The electronic control unit (ECU) of ABS traces the speed of rotation of each of car wheels, being guided by the signals arriving from wheel sensors. When at emergency braking any of wheels it begins to be blocked prematurely, ECU issues the command for activation of the hydraulic modulator of the electromagnetic valve placed inside which, working, opens the respective site of a brake contour, releasing from it a part of hydraulic liquid in the tank and, respectively, reducing working pressure. As soon as speeds of rotation of wheels are equalized, the valve is closed again and pressure continues to rise. The cycle lasts fractions of a second on each of wheels and repeats until braking is not complete. The design of system allows to correct pressure in hydraulic contours of each of four wheels. Actually the scheme of functioning of ABS is much more difficult, than it can seem therefore authors of the present manual do not recommend to owners of cars to make attempts of independent performance of repair of system. In case of malfunctions it will be most reasonable to address specialists of car service.

Failure diagnostics and codes of malfunctions

If the control lamp of ABS which is built in in the car dashboard lights up and continues to burn during the movement, first of all make sure that the parking brake is completely released, and the brake system functions regularly. If all normal, therefore, there was ABS refusal. Do not forget that operation of a control lamp of ABS can be caused by decrease in level of brake fluid in the GTTs tank, - also control lamp of the brake system at the same time will work. Constant, not connected with wear of frictional overlays of blocks, the consumption of brake fluid speaks about existence of leaks in a hydraulic path:

a) Check a condition of brake supports and wheel cylinders;
b) Check components of a hydraulic path for existence of signs of development of leaks;
c) Check a state and reliability of fastening of contact sockets of an electrical wiring of ECU and wheel sensors (see the Head Onboard electric equipment);
d) Check the corresponding safety locks (see the Head Onboard electric equipment).

The module of management (ECU) of ABS monitors any violations of functioning of components of system. In case of identification of refusal on the dashboard the corresponding control lamp lights up, the system of anti-blocking of brakes is disconnected. In memory of the module of management at the same time the refusal code registers.

At inclusion of ignition the control lamp of ABS gives two (FWD models) or four (AWD model) flashes within 1 second, then has to go out.

If during performance of independent checks it is not possible to reveal any violations, drive away the car on car repair shop. Full diagnostics of ABS demands use of the special DRB-II or MUT-III reader connected to the diagnostic DLC socket located at the left under the dashboard.

List of codes of malfunctions of ABS

Diamante 1992 ÷ models of 1996 of the issue.

The Diamante models since 1997 of the issue.

The Galant models for 1993 the issue.

Galant 1994 ÷ models of 1998 of the issue.

The Galant models since 1999 of the issue.

Mirage 1993 ÷ models of 1996 of the issue.

The Mirage models since 1997 of the issue.