I have a 1999 F150 with a 5.4L. I recently replaced the PCM with a new unit from autocomputerexchange.net that was programed for my truck. I installed the PCM but the truck did not start. The theft light is also flashing rapidly during cranking. I ran a code scanner a recieved the code P1260 indicating an attemped theft which disabled the truck. I read that if you have two keys you can sync the keys with the new computer but unfortunatly one of the keys stopped working a couple years ago (not sure why, stopped for gas and it never started back up). Since i do not have two working keys do i have to tow the truck to a dealer and let them reprogram the keys and reset the PATS or can i have a locksmith recode the keys and sync the keys myself.

hope the wasn't too long winded.

thanks for your help.

 

You need to take it to a dealer for a second spare key and programming.
The Pats marries the PCM by code.
That's the Theft protection you have with the keys and the Pats association with the PCM.
You can't even change out the dash cluster for this fact.
Good luck.

 

The cluster, the PCM, and the key(s) are all "married" to each other. Change any of them and it needs to be re-done.

A dealer can certainly do it as well as can any well-equipped locksmith. You'll have to call around your local area and ask. You can buy the programmers off ebay out of China for around $350 last time I looked.