Barometric Pressure Sensor: Operation

• The barometric pressure sensor functions to convert the barometric pressure to voltage, and to input that voltage (as signals) to the engine control unit. The engine control unit, based upon those signals, then corrects the amount of fuel injection, etc. See Fig 1 .
• The 5-volt power supply within the engine control unit is supplied to the barometric pressure sensor. It passes through the circuitry within the sensor, and is grounded at the engine control unit.
• The barometric pressure sensor output voltage is sent to the engine control unit in proportion to the barometric pressure (absolute pressure).

Fig 1: Identifying Barometric Pressure Sensor Circuit

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.