I have a 2002 F350 7.3 diesel crew cab. I have owned this truck since new. Love the truck but I have a problem I can't figure out. The truck has the factory installed power door locks with factory key-less remote transmitter (key fob). I only have 1 original keyless remote transmitter and about a year ago it quit working. The lock , unlock and panic button on the fob do nothing. All doors lock and unlock fine from the door panel buttons and with the key . I replaced the key fob battery (lost the second OEM key-less remote transmitter) reprogrammed the key fob with the (TIC) procedure from my ford operators manual off-run eight times with the eight time ending on the on position. The programming works (doors lock then after hitting any button on the key fob) doors then lock unlock then when turning the key to off ends the programming mode and doors lock and unlock to confirm success. No problem with the TIC process. Tried the key fob and nothing no lock , unlock or panic button function. So I tried ordering a couple of aftermarket key fobs (remotes) and reprogrammed all three remotes OEM and two new aftermarket , still, nothing. I also read locking and unlocking the door before starting the reprogramming procedure helped other people with a similar problem or disconnecting both of the 12 volt truck batteries under the hood and reconnecting after an hour. I tried both of these ideas.... still no change. Is there a security module I can check fuses on? I read somewhere that a GEM (generic electronic module) might be the problem. Is this the security control for the truck? From what I read this devise handles the communication of the key fob to the trucks door lock and unlock functions. I hear this is a $500 devise and must be flashed by the dealer with my VIN before it can be used. Does anyone know if there is a fuse I can check for this GEM devise? Any help would be greatly appreciated.