What is the function of the automobile intake pressure sensor?

The vacuum tube is connected with the intake manifold. With the different engine speed load, it senses the change of vacuum degree in the intake manifold, and then it is converted into a voltage signal by the change of sensor internal resistance for ECU to correct the fuel injection quantity and ignition timing angle.

The most common intake pressure sensors are three-wire and four-wire sensors. The pins of the three-wire sensor are defined as power supply, grounding and intake pressure signals respectively. The four-wire sensor has one more intake air temperature signal than the three-wire sensor.