WS3-6

MAP Digital :

This sensor calculates the pressure inside the intake manifold so the ECU knows how much air is going inside the engine so it can adjust the air/fuel ratio accordingly . Some people like refering to this sensor as Vacuum sensor . We can see in the photo above there is high vacuum in the manifold therefore a low output volatge but as we rev the engine up the air inside the intake manifold increases due to the throttle butterfly allowing more air past it this means less vacuum inside the manifold or more pressure inside the intake manifold , consequently this will increase the output voltage of signal wire back to the ECU. which we can see as the peaks on the graph above.