Manifold Pressure/Vacuum Sensor: Description and Operation

Voltage Versus Pressure Chart:

The Manifold Absolute Pressure (MAP) sensor responds to changes in intake manifold pressure. The PCM supplies a 5 volt reference and a ground for the MAP sensor. The MAP sensor provides a signal to the PCM relative to the pressure changes in the manifold. The MAP sensor signal voltage to the PCM varies from below 2 volts at idle (low manifold absolute pressure - high vacuum) to above 4 volts with the key ON, engine not running or at wide-open throttle (high manifold absolute pressure - low vacuum).

If the PCM detects a voltage that Is lower than the possible range of the MAP sensor, DTC P0107 will set. A signal voltage higher that the possible range of the MAP sensor will set DTC P0108. An intermittent low or high voltage will set DTC P1107 or P1106 respectively.