Schematic diagram of function and location of Passat b5 1.8t intake pressure sensor.

The intake pressure sensor of Passat B5 is located between the intake manifold and the throttle, as shown in the following figure:

The intake pressure sensor is mainly used to measure the vacuum degree of the intake system. For example, for an engine with an electronic valve control system, the rotational speed is set to about 5000Pa (50mbar) at idle speed.

) vacuum, intake pipe vacuum as a backup parameter of load signal.

By detecting the pressure of the intake pipe, the accurate value of the air volume of each cylinder can be calculated. According to this value, the opening time and injection quantity of the intake valve are adjusted accordingly.

There are two kinds of intake pressure sensors: three-wire and four-wire. The difference is that there is an intake temperature signal in the four wires, which are positive electrode, negative electrode, intake air volume signal and intake temperature signal respectively! Damage phenomenon of intake pressure sensor:

1, engine starting is difficult.

2. Abnormal engine performance.

3. The idle speed is unstable.

4. Fuel consumption increased.

5, the acceleration is weak.

In the electronically controlled multi-point fuel injection system, it is very important to accurately measure the air quantity entering the engine. This signal is the main basis for the electronic control unit to accurately calculate the fuel injection quantity. In multi-point fuel injection system, sensors can be divided into two types according to the method of measuring air flow, namely intake manifold pressure sensor (negative pressure type) and air flow sensor.