A barometric pressure sensor is a sensor that detects atmospheric pressure. Various types of pressure sensors exist utilizing different materials and methods as shown below based on the pressure values to be measured. Among these, sensors that detect atmospheric pressure are called barometric pressure sensors.

Where are these Barometric Pressure Sensors located? Standalone BARO sensors are typically mounted on the firewall or the inside fender skirt. Late model BARO sensors are incorporated into the MAP sensor, and may be mounted on the intake manifold.

OBD II fault code P2227 is a generic code that is defined as “Barometric pressure (BARO) sensor- range/performance problem”, and is set when the PCM (Powertrain Control Module) detects a reading from the Barometric Pressure Sensor that is incompatible or irreconcilable with the current engine load and throttle opening.

The BARO sensor can be checked with a scan tool by comparing the scan tool read out to the local barometric reading. Standalone Ford sensors require a special tool to determine if the sensor is functioning properly. The ECM will set DTC P0105 when there is an open or short in the BARO circuit.

A faulty MAP sensor will affect an engine’s air-fuel ratio. If the ratio is incorrect, ignition inside the engine will occur at an improper time in the combustion cycle.

The barometric sensor, also commonly known as the barometric air pressure sensor (BAP), is a type of engine management sensor commonly found on many vehicles. However, the BAP measures the pressure outside of the engine, while the MAP measures the pressure inside of the manifold.

If the MAP sensor is not reporting boost pressure to the computer correctly, or the computer is not processing the sensor inputs correctly, or the wastegate is not opening, the engine can experience over-boost, detonation and possible damage.