Manifold Pressure/Vacuum Sensor: Description and Operation
MAP SENSORDESCRIPTION
The Manifold Absolute Pressure (MAP) Sensor, is mounted to the front of the engine on the right side next to the air pump.
DESCRIPTION - SRT
The Manifold Absolute Pressure (MAP) Sensor is mounted in the Charge Air Cooler below the Throttle Body. The sensor allows the PCM to monitor air pressure within the intake manifold. The sensor is used to measure both vacuum and positive pressure (supercharger).
OPERATION
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.
OPERATION - SRT
On the Supercharged 3.2L engine, the MAP serves as a PCM input, using a silicon based sensing unit, to provide data on the manifold vacuum/pressure that draws/pushes the air/fuel mixture into the combustion chambers. The PCM use the map data combined with the intake air temperature to determine the volume of air entering the engine.