Installed on the surge tank, Manifold Absolute Pressure Sensor (MAPS) is a speed-density type sensor that senses absolute pressure of the surge tank and transfers the analog signal proportional to the pressure to the ECM. By using this signal, the ECM calculates the intake air amount and engine speed.

The MAPS consists of a piezo-electric element and a hybrid IC amplifying the element output signal. This element, a silicon diaphragm type, features pressure sensitive variable resistor effect of semi-conductor. Due to 100% vacuum status and manifold pressure applied to both sides of the sensor, this sensor can output analog signal by using the silicon variation proportional to pressure change.