Manifold Pressure/Vacuum Sensor: Description and Operation

The Manifold Absolute Pressure (MAP) sensor, is mounted to the front of the engine on the right side next to the air pump.

The MAP sensor monitors the pressure in the intake manifold. The pressure in the manifold moves a diaphragm connected to piezo resistors which alter their resistance values. The output voltage of the resistors serves as information to the PCM about the pressure in the intake manifold.