Operation CHARM: Car repair manuals for everyone.

Vacuum Sensor

NOTE: If vehicle is not equipped with a MAP sensor, it may be equipped with a vacuum sensor--some systems may not use either.

Sensor produces low voltage--approximately 1 volt--when manifold vacuum is low, and higher voltages--approximately 4.5 volts--when vacuum is high.

Normal output is 0.54-0.62 volts with ignition ON and engine stopped.