Manifold Pressure/Vacuum Sensor: Description and Operation

VOLUME AIR FLOW (VAF) SENSOR
The VAF Sensor measures the intake air volume. It makes use of a Karman vortex to detect the air flow rate and sends it to the ECM as the intake air volume signal. The ECM uses this intake air volume signal to decide the basic fuel injection duration.

This is the pressure sensor that converts the pressure value into an electric signal and provides the signal to ECM. If the differential pressure is over -11 Hg. (in case of manual transmission ), -26 Hg. (in case of auto transmission ),the MDP sensor is expected to operate. If EGR valve does not then operate, there is a problem with the EGR valve.





The value of MDP (manifold differential pressure sensor) has the correlation with the pressure. Refer to the graph as shown in the illustration.

Vo = 0.06(P) + 4.760 P : Hg