Barometric Pressure (BARO) Sensor
WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2018 Ford Transit-350 HD, 2018 Ford Transit-350, 2018 Ford Transit-250, 2018 Ford Transit-150, and 2018 Ford F-550 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
The BARO sensor is a variable capacitor sensor that is supplied a 5-volt reference signal by the PCM and returns a voltage signal to the PCM relative to the intake manifold pressure. The sensor voltage increases as the pressure increases. The BARO sensor is integral to the PCM.