Boost Pressure Gauge
WARNING: This page is about a different car, the 2012 Ford Pickup, 2012 Ford F550 Super Duty, 2012 Ford F450 Super Duty, and 2012 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
The boost pressure gauge is controlled by the instrument panel cluster. The powertrain control module (PCM) sends a message through the controller area network (CAN) to the instrument panel cluster indicating engine boost pressure.