Barometric Pressure Sensor: Description and Operation

Atmospheric Pressure Sensor:

The Atmospheric Pressure Sensor, located on the firewall in the engine compartment, detects changes in barometric pressure related to changes in altitude from sea level. The sensor converts these changes to an electrical signal utilized by the ECU in its calculations of fuel injection quantity, idle speed and ignition timing control. The signal voltage ranges from 3.5 - 4.5V at sea level to 2.5 - 3.5V at high altitude (2000 meters, 6500 feet).