Manifold Pressure/Vacuum Sensor: Description and Operation

Fig. 32 MAP Sensor And Voltage Output Characteristics:

The MAP sensor converts manifold absolute pressure into electrical signals and inputs to the ECU. With manifold absolute pressure high (no vacuum) the MAP sensor output is typically 2.75-3.00 volts, under low manifold absolute pressure (high vacuum) 25 in.Hg the output is 0.5-0.75 volts.