Boost Pressure Monitor
WARNING: This page is about a different car, the 2021 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.
The PCM determines if the correct amount of boost is being generated, in response to engine speed, load, manifold pressure and barometric pressure values. If the boost pressure is lower or higher than expected, a DTC is stored and the MIL is illuminated.