Mainfold Absolute Pressure (MAP)

Mainfold Absolute Pressure (MAP) sensor.

I had wired up MAP sensor with a 5V pwer suplay earth. Meassure from the thired return wired , and used a multi vac app;y vacum to the MAP sensor .
The yellow is power 5v , brown is gronded, and blue is refrence or out put voltage.

In this graph i have recorded diffrent voltages reading according to the diffrent vacum , it show that the MAP sensor straight for every vacum reading it is spicefied voltage of MAP sensor.

In this picture readig of 3.62V at 5 In / Hg of vacum.

In here is reding 1.2V at 35 In / Hg vacum.

Internal or inside of MAP sensor is silicon diaphagram that diaphagram increse resistance when vacum applied , so the out put voltage of sensor is decreases. At idle engine sucking more and vacum is high , but it revers up vacum is geting lower , according to that reading ECU adds requre amount of fuel nedded.
Watch vidio belw we can see changing of voltage down when vacum apply to sensor.