Barometric Pressure Sensor: Description and Operation

^ The atmospheric pressure sensor, located in the ECU, detects changes in barometric pressure corresponding to changes in altitude from sea level.
^ Changes are converted to an electrical signal (approximately 4V at sea level) and monitored by the ECU primarily for EGR control.
^ At high altitude (above 1000 meters, 3,280 feet), the ECU will decrease the amount of exhaust gas recirculated.