Manifold Absolute
Pressure Sensor (MAPS) is a speed-density type sensor and is 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 silicon diaphragm type and adapts pressure
sensitive variable resistor effect of semi-conductor. Because 100% vacuum
and the manifold pressure apply to both sides of the sensor respectively,
this sensor can output analog signal by using the silicon variation
proportional to pressure change.