Barometric Pressure Sensor (BPS) is a speed-density type
sensor and is installed on the air cleaner assemby. It senses absolute
pressure of the air cleaner assemby 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
that amplifies the element output signal. The element is silicon
diaphragm type and adapts pressure sensitive variable resistor effect of
semi-conductor. Because one end of the silicon diaphragm is 100% vacuum
and the manifold pressure applies to the other end, the sensor output
can be achieved in analog signals from the silicon variation
proportional to pressure change.