Kia Niro: Engine Control System / Manifold Absolute Pressure Sensor (MAPS) Description and operation

Manifold Absolute Pressure Sensor (MAPS) is a speed-density type sensor installed on the surge tank. It 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 quantity and engine speed.

The MAPS consists of a piezo-electric element and a hybrid IC amplifying the element output signal. The element is made of silicon diaphragm, which has the pressure sensitive variable resistor effect of semi-conductor. One side of silicon diaphragm is 100% vacuum and manifold pressure is applied on the other side. Hence, output is gained from the silicon variation in proportion to the pressure change.