"Check Fuel Fill Inlet" light is not resetting on my 2009 F-150. How do I fix?

the FSM book covers this. (ill do the full tank pull... as you never said the JOB!)
its siphoned to near empty. (use a hand pump for fuel , sold at all boat center)
do you need the FSM page quotes?
on some cars there is an anti-spill roll over check valve
at tank fill port making siphoning very hard.
my answers are USA cars, on this USA forum.... and swifts vary big time world wide..... dig?

quoted. (no smoking no open flames, outdoors best. no shop heaters of ANY KIND near)
"tank pull steps. (sure drained)

1. Before servicing the vehicle, refer to the Precautions section.
2. Relieve the pressure from the fuel system. (in the FSM)
   
3. Disconnect the negative battery cable.
4. Remove rear seat cushion.
5. Disconnect connectors of fuel tank wire harness.
6. Hoist vehicle.
7. Disconnect fuel tank filler hose and breather hose from filler neck.
8. As fuel tank has no drain plug, drain fuel tank by pumping fuel out through fuel tank filler or fuel tank inlet. Use hand operated pump to drain fuel tank.
9. 1. Disconnect fuel pipe joints and fuel hose from pipes. For quick joint, disconnect it as follows:
      
      • Remove mud, dust and/or foreign material between pipe and joint by blowing compressed air.
      • Unlock joint lock by inserting special tool (part No. 09919-47020) between pipe and joint.
      • Disconnect joint from pipe.
   2. Remove fuel tank from vehicle.

The sealing flap is not closing properly, most likely because of dirt on the rubber seal. Stick the fuel filler nozzle in and out 5 or 6 times slowly. This may dislodge the dirt. You can try blowing some compressed air around the flap also.

It may take a day or 2 for the check fuel fill inlet light to go out after you dislodge the dirt.

If that doesn't work, you have to replace the whole assembly. Any Ford Lincoln Mercury dealer will be able to order the part.

Check to see if your gas cap is on tight.

It is rare that this will help, but sometimes if you fill the fuel tank all the way to the top of the fuel inlet (where you put gas in) it can "unstick" the float.

One possible reason a float sticks is someone overfilled the tank.

If the check fuel fill inlet lamp or CHECK FUEL FILL INLET message
comes on, the fuel fill inlet may not have properly closed. The inlet may
have stuck open or debris may be preventing the inlet from fully closing.
At the next opportunity, safely pull off the road, turn off the engine,
open the fuel filler door and remove any visible debris from the fuel fill
opening. Insert either the fuel fill nozzle or the fuel fill funnel (see
Refilling with a portable fuel container for funnel location) provided
with the vehicle several times to dislodge any debris and/or allow the
inlet to close properly. If this action corrects the problem, the check fuel
fill inlet lamp or CHECK FUEL FILL INLET message may not reset
immediately. It may take several driving cycles for the check fuel fill inlet
lamp or CHECK FUEL FILL INLET message to turn off. A driving cycle
consists of an engine start-up (after four or more hours with the engine
off) followed by city/highway driving. Continuing to drive with the check
fuel fill inlet lamp or CHECK FUEL FILL INLET message on may cause
the service engine soon lamp to turn on as well.
WARNING: The fuel system may be under pressure. If you hear
a hissing sound near the fuel filler door (Easy Fuel "no cap"
fuel system), do not refuel until the sound stops. Otherwise, fuel may
spray out, which could cause serious personal injury.

Yes, the flap must seal the hole or the Vapor system will generate an error code. The Flap may be damaged or the spring has broken or as you mentioned, if it's really cold, could be frozen open. Use a flashlight to examine the filler hole and see if the flap is still there. How to fix ford fuel fill inlet problem

check the filler door to se if it closes all the way..some snap shut..

I know my barrina when gas cap was missing had check engine light on did diagnostic said o2 sensor as well so got a cap from gas station reset computer now no lights on everything fine had something to do with pressure in tank not right

there are hundreds of causes. Look here: http://alflash.com.ua/OBDII/EOBDcodes.pdf

You need to have the car scanned to get the codes. many parts stores such as autozone and advance will do a free scan.

DESCRIPTION
A restricted or blocked evaporative emission (EVAP) vent path is detected by the control module monitoring the fuel tank pressure (FTP) during normal operation. The control module commands the EVAP vent valve OFF, or open, and the EVAP canister purge valve ON, or open. The fuel tank pressure should remain low as vacuum is drawn on the EVAP system. If the vent path is blocked or restricted, the vacuum level will increase and DTC P0446 will set.

DIAGNOSTIC AIDS
An intermittent Condition could be caused by a damaged EVAP vent housing, a temporary blockage at the EVAP vent valve inlet, or a pinched vent hose. A blockage in the vent system will also cause a poor fuel fill problem.