DTC P2227: Description
WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
The DTC P2227 Barometric Pressure (BARO) Sensor Performance diagnostic checks the accuracy of the BARO sensor signal. The BARO sensor and circuitry are located inside of the powertrain control module (PCM). Barometric pressure varies with weather conditions and changes in the altitude from sea level. The PCM modifies fuel and spark delivery in response to barometric pressure changes. The PCM compares the BARO sensor reading with the manifold absolute pressure (MAP) sensor reading when running the DTC P2227 diagnostic.