Barometric Pressure (BARO) Sensor
WARNING: This page does not describe the selected car, but rather 32 other vehicles, including the 2011 Mercury Milan, 2011 Mercury Mariner, 2011 Mercury Grand Marquis, 2011 Lincoln Town Car, and 2011 Lincoln Navigator L. However, it is still accessible from the selected car via links, so may be relevant.
The BARO sensor directly measures barometric pressure to estimate the exhaust back pressure. Exhaust back pressure influences speed density based air charge computation. The BARO sensor is mounted directly to the PCM circuit board.