so this has me a little stumped.
There are 3 antenna to receive the keyfob ID. One near the driver door, one near the front passenger door, and one at the rear bumper.
if the presence of the keyfob unlocks the door, then shouldn't it also permit the vehicle to be started?
i had the key not detected problem in the past, replaced the fob battery, but still had the problem.
A workaround was to slap the fob between my hands.
The permanent solution was to remove the fob battery, expand the four fingers that contact the battery, so that they put greater pressure on the battery, and then close it all up.
It seems the fingers were just not making good contact with the battery, and after expanding them (be careful not to break them) the problem has not occurred since.
Re: "Key Not Detected" can strand you, Solution Here
Actually, this specific problem, by a poster with 1 post, is running up against the strict anti-Theft security Ford has built-in to it's vehicles to prevent a stranger from hopping in somebody's Ford & taking off with it!
If the poster has a real legitimate problem, as in the car's computer "forgot" what the internal security key FOB code is, as is alleged, THEN the only hope is to disconnect the 12v battery and maybe it will cause the computer to retrieve the code properly this time. It could be the previous 12v battery problem mentioned went through off-on-off-on bouncing, creating a possbile software initialization problem. Who knows.
Otherwise the owner needs to tow it to a dealership, prove owership, and they should be able to fix it.