Barometric Pressure Sensor (BPS) is a speed-density type
sensor and is installed on the air cleaner assembly. It senses absolute
pressure of the air cleaner assembly 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 BPS 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 one side of the silicon diaphragm is 100% vacuum
and the other is affected by the manifold pressure, this sensor can
output analog signal by using the silicon variation proportional to
pressure change.