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REPAIR MAINTENANCE OPERATION OF MOTOR VEHICLES
Volkswagen Passat B5 (from 1996 to 2004, the year of issue)

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Volkswagen Passat B5
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Systems ABS / EBV / EDS / ASR / ESP



ABS. Anti-lock brakes

Braking performance is greatest when the grip of the tire with the road surface is greatest. During braking, tire slips on the surface, and the circumferential speed of the wheel becomes smaller than the vehicle speed.

Sliding minimum (0%), when the wheel is rolling freely and the maximum (100%), when the wheel is locked. The maximum braking efficiency is achieved when the slip is 15%. This value also allows you to maintain the stability and handling.

The role of the anti-lock system is to limit the pressure generated in the hydraulic brake system, so that the value of the slip was kept near the optimal value (15%). The effect of this system should be immediate and separate for each wheel. The system should respond immediately to each change of the surface (coefficient of friction), and the load on the car.

The anti-lock system of the firm TEVES (ATE) in one unit performing the functions of energy, drive and brake servo and control anti-lock wheels. The hydraulic unit is installed instead of the vacuum booster is fitted as standard with a built-in brake master cylinder. Installation ABS is only possible in the factory in the manufacture of the car and can not be installed separately. Anti-lock braking system prevents the wheels from locking under heavy braking. This reduces the braking distance, especially under low grip in the rain and snow. The adhesive force between the wheels and the road in this case is greater when the braking wheel continues to rotate. In addition, even if full braking the vehicle remains controllable. Speed sensor, one for each wheel is measured by the speed of rotation of the wheel. According to signals from the sensor wheel revolutions in electronic control unit calculates the average speed approximately corresponding to the vehicle speed. Comparing the speed of each individual wheel from the average speed calculation, the electronic unit determines individual wheel slip state, and thus determines which wheel is in predblokirovochnom condition.

When one of the four speed sensors transmit a signal to block the respective wheels, once the electronic control unit sends a signal to a corresponding closing of the inlet solenoid valve, which immediately shuts off the brake fluid through the brake line to the brake of the wheel - braking force remains constant. If you still slide continues, the exhaust valve opens and the pressure in the hydraulic system of the brake is reduced - the wheel is not braked (surplus brake fluid back into the tank). Once again, the wheel starts to spin, then immediately comes the opening of the inlet valve and closing the exhaust valve. Circuit pressure increases, and the wheel is braked again.

This cycle of braking and free-wheel speed is very fast (several times per second) and continues until the car stops or until you release the brake pedal.

This process is repeated when braking for each wheel, as long as the brake pedal is released or when the vehicle speed decreases to 2-3 km / h. The driver determines the ABS operation of the brake pedal pulsation.

Emergency shutdown system will disable the ABS for any failure or low voltage in the electric vehicle network (below 10V). The electronic control unit also serves as diagnosticians aggregate function, warning the driver fire of a control bulb of the registration failure of electrical circuits or elements of an anti-lock system. When a faulty ABS system brake, however, intact and functioning as if the system is not in the car.

EBV. The electronic distributor of braking force to the rear wheels

The electronic distributor of braking force acts as a mechanical regulator of pressure, but it works more accurately and has a wide range of adjustment. When the vehicle is moving in a straight line is completely open flow of brake fluid to the brakes of the rear wheels. To ensure stable cornering braking supply brake fluid to the rear brakes is limited. On the basis of the sensor signals of the wheels of the ABS control unit EBV detects when the car is moving in the rotation. When passing vehicle cornering braking force transmitted to the rear wheels is reduced, thereby reducing the likelihood of skidding.

EDS. Electronic Differential Lock

As a complement to the elements of the ABS, EDS reduces the transmission of torque under adverse driving conditions, especially on the climbs and acceleration of the vehicle, eliminating the slippage of one of the drive wheels. Due to the mechanical differential lock is achieved by improving the transmission of torque, as this party with a higher coefficient of friction can transmit higher torque.

The electronic control unit receives information from the ABS sensors of rotation speed of the drive wheels and constantly compares them. In the presence of rev difference above about 110 rev / min EDS automatically activated and decreases the transmission torque to the revolving wheel as long as it will have approximately the same speed and slipping wheels. With this control reaches Xia that to the wheel with better traction transmitted to the increased torque. EDS is automatically disabled when the vehicle speed is above 40 km / h, as well as cornering and overheating brakes.

ASR. The system reduce engine torque transmitted to the drive wheels

Reduced torque slipping both the drive wheels is accomplished by reducing engine power. In this case, the power of the engine is limited so as to transmit only the torque required to drive the vehicle.

ASR system should always be included. Only in certain exceptional cases where the desired wheel slip, preferably a system shut down.

ESP. Electronic Stability Program

Through the stabilization system control is performed for vehicle dynamics in limit conditions, for example by overcoming turns at high speed. The danger of demolition or skidding is reduced significantly under all possible road conditions.

The electronic stabilization system integrated anti-lock brakes and probuksovochnye system. The Electronic Stability Program additionally measured the speed of movement of the body around the vertical axis, the value of the acceleration in the transverse plane, the pressure in the brake actuator and the steering angle. On the basis of the angle the steering and speed of the vehicle determines the direction in which the driver of the car is going to move, and it is constantly compared with the actual behavior of the vehicle. When the inconsistency of these factors when starting the demolition or skid car, the system automatically brakes the stabilization of certain wheel.

If a fault occurs electronic control system automatically shut down, and the instrument cluster warning lamp. In this case, the braking system is working normally.

If during movement the control lamp ABS and EBV, keep in mind that during heavy braking may occur blocking the rear wheel.

When lit, one or more indicator lights while driving signals the system is turned off. At the same time, follow these steps.
PERFORMANCE ORDER
1. Stop the car, turn off and restart the engine.
2. Check the battery voltage. If it is below 10.5 V, charge the battery.
A warning

If the ABS warning lamp is lit at the beginning of the trip, and then goes out, this indicates that the voltage was permissible limit for ABS, but then rose as a result of the generator.


3. Check the condition of the battery terminals.
4. Raise the car, remove wheel and check that the wiring wheel speed sensors.
5. If the problem persists, then further testing should be performed at the service station.





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