Fuel Level Input (FLI)
WARNING: This page does not describe the selected car, but rather 32 other vehicles, including the 2010 Mercury Milan, 2010 Mercury Mariner, 2010 Mercury Grand Marquis, 2010 Lincoln Town Car, and 2010 Lincoln Navigator L. However, it is still accessible from the selected car via links, so may be relevant.
The FLI is a communications network message. Most vehicle applications use a potentiometer type FLI sensor connected to a float in the fuel pump (FP) module to determine fuel level.