(i) MAP Sensor:

• The manifold absolute pressure sensor (MAP sensor) is one of the sensors used in an internal combustion engine's electronic control system. As the name suggests it is positioned in the inlet manifold.
• The manifold absolute pressure sensor provides instantaneous manifold pressure information to the engine's electronic control unit (ECU).
• This sensor is typically a diaphragm type vacuum gauge where the vacuum is measured against a reference vacuum.
• The position of the diaphragm is sensed by a silicon chip and information is sent to the ECU which looks up a table and the pressure is identified.
• Figure shows positions of the sensor when there is a high pressure and low pressure in the intake manifold.