Description

The Manifold Absolute Pressure Sensor (MAPS) is a speed-density type sensor and is installed on the surge tank. It senses the absolute pressure in the surge tank and sends an analog signal proportional to the pressure to the ECM. Using this signal, the ECM calculates the intake air quantity and engine speed. The MAP sensor consists of a piezoelectric element and a hybrid integrated amplifier circuit. The element outputs a signal from the element. The element is a silicon diaphragm and acts as a pressure-sensitive variable semiconductor resistor. Because 100% vacuum and intake manifold pressure are applied to the two sides of the sensor respectively, this sensor can output an analog signal by proportional change of the silicon in response to pressure changes.