Barometric Pressure Switch: Description and Operation

Barometric Pressure Sensor Circuit:

The Barometric Pressure Sensor, located in the Air Flow Sensor (AFS), senses the atmospheric pressure and converts it into a Voltage which is sent to the ECU. The ECU uses this signal to compute the altitude at which the vehicle is running, accordingly correcting the air-fuel ratio and the ignition timing, thus improving driveability at high altitude.