September 30: LEMON manuals is back up on a temporary server! Slowness is possible
Fuel Tank Pressure Sensor
WARNING: This page is about a different car, the 2004 Ford Pickup Heritage. However, it is still accessible from the selected car via links, so may be relevant.
The fuel tank pressure (FTP) sensor is integral to the gas regulator. It provides information on CNG fuel tank pressure to the AFCM and is also used to determine the alternative fuel gauge reading.
Courtesy of FORD MOTOR CO.