Arrangement of elements of brake system with ABS on the car
| 1 – a tube of a highway of a high pressure of brake system;
2 – a brake pedal;
3 – the main brake cylinder;
4 – пополнительный a tank;
5 – the vacuum amplifier of brakes;
6 – the block of hydraulic management (HCU);
|7 – the forward disk brake mechanism;
8 – a support;
9 – the back drum-type brake mechanism;
10 – the lever of a lay brake;
11 – a cable of a lay brake.
The block of management ABS carries out following functions:
– Operates ABS;
– Calculates speed of the car;
– Spends system self-diagnostics: codes of malfunctions with self-diagnostic and safety functions are brought in memory by two separated microprocessors.
The block of management ABS continuously checks blocking of each wheel and operates each valve to regulate pressure of a brake liquid if it is required.
The block of management ABS also checks that components work properly and switches off ABS at detection of failures.
Then the brake system works as standard brake system.
The gauge of frequency of rotation
The gauge of frequency of rotation finds out rotation of a wheel and consists of a constant magnet and the coil. Gauges of forward wheels receive the information from the gear rotors located on power shafts.
At passage of teeths of a rotor about the gauge, the gauge magnetic field therefore the pressure impulse is developed changes.
This pressure is proportional to frequency of rotation of a wheel and can be measured.
Control lamps ABS and EBD are located in a combination of devices.
Control lamp ABS:
1) Burns during 3 with the ambassador of inclusion of ignition then dies away.
2) Dies away at engine start-up.
3) If the lamp burns constantly, means in ABS there are infringements.
4) the Lamp burns during self-diagnostics.
5) If the control lamp lights up periodically, means in ABS there are infringements and work of systems of the car is carried out thus as though in the car there are no systems ABS and TCS.
6) the Lamp burns at a detachment of an electric socket from the block of management ECU.
Control lamp EBD (electronic distribution of force of braking):
1) Burns after ignition inclusion.
2) Dies away at engine start-up.
3) Burns at a tightening of the lever of a lay brake.
4) Burns at low level of a brake liquid.
5) Burns, if electronic distribution of force of braking EBD does not work:
– At malfunction in the electromagnetic valve;
– At malfunction more than in one gauge;
– At malfunction of the block of management ECU;
– At pressure excess.
The block of hydraulic management (HCU)
The block of hydraulic management (HCU) consists of the pump with an electric motor and the block of valves to operate pressure ABS.
The gauge is located in the electric motor of the pump and transmits a target signal to block ABS which defines working capacity of the pump.
Diameter of an aperture of a pipe of giving of a brake liquid of a forward brake: 4,8 mm
Diameter of an aperture of a pipe of giving of a brake liquid of a back brake: 4,8 mm
The pump with two contours provides demanded pressure, and the block of valves distributes the pressure transferred to wheel brake mechanisms.
||And – the forward right inlet valve;
In – the back left inlet valve;
With – the back right inlet valve;
D – the forward left inlet valve;
E – the forward right final valve;
F – the back left final valve;
G – the back right final valve;
H – the forward left final valve;
M – + the engine;
N – the engine (GND).
The block of management ABS starts to carry out self-diagnostic functions after ignition inclusion. The block of management ABS finds out malfunction for each contour and a component, comparing a condition of system to the limited set of conditions in the block of management ABS. The block of management ABS stores a code of malfunction and then deduces on the diagnostic device in the form of the codes designated in four figures.
Check of codes of self-diagnostics
| PERFORMANCE ORDER
| 1. Turn a key in the ignition lock in position OFF and connect the diagnostic device to the diagnostic socket located about the vacuum amplifier in a motor compartment.
||2. Turn a key in the ignition lock in position ON and on the device set model of the car and model of the diagnostic device.
| 3. Choose the checked parametre after block initialization.
|4. Press check of codes №1 and find out, whether malfunction is written down.
Malfunction code – number with four figures which appears continuously while the malfunction code is not erased by the diagnostic device.
|5. Under the list of codes of malfunction reveal a faulty element and restore its working capacity.
||6. After deleting of codes of malfunction from memory of the block of management ABS choose inspection point №4.