Passat Lingyu driver's side front of the location of abnormal sound

A mileage of auto code reader 110,000 km 2007 Passat 1.8T Volkswagen Passat GLS sedan. Users reflect similar turn signal to turn on the sound in the car driving in front of the driver's side position, and when the time is now hidden.

The examination analysis: the maintenance staff and users with road test, finally heard the faint sound of the user prompts. That such a sound from the instrument sets the bottom left of the relay area, is issued by the repeated action of a relay. Lingyu automatic car configuration of the brake vacuum pump, the engine control unit J220 Upon detecting the insufficient degree of vacuum within the vacuum booster, and will immediately start to brake vacuum pump, in order to maintain a specific degree of vacuum.

In view of this noise auto diagnostic tool, should be a brake vacuum pump relay (Figure 18) J564 (373) issued by the contact action, which indicates that the brake system has the potential problem of air leakage. Detecting an engine control unit, and found that the fault code 17887 ---- brake vacuum pump mechanical failure, incidental. In order to clarify whether the vacuum system is really exist a leakage problem, and viewed a state of mixed gas, and found that long-term fuel correction amount is 9.0%. Considered together with the degree of vacuum, the vacuum system can be seen that there is indeed a leakage problem.

To further clarify, the view in auto scanner the engine idling, the engine control unit 8 Zone 3 data, found that the air in the brake booster pump pressure of 58.5 kPa absolute, is too high. Observe the engine idling state, appears to be very stable, but this is the result of long-term fuel correction enriched.

Carefully checked into the trachea and its surrounding conduit and the check valve, and found that there are two one-way valve leakage (Figure 19), wherein the jet pump at the one-way valve leak vacuum booster vacuum reserve will produce a certain affect

Troubleshooting: 8 Zone 3 data auto diagnostic software after replacing the one-way valve, re-read, the air pressure becomes 17 kPa normal. Road test certificate again, the original relay contacts occur frequently pull sound no longer appeared.