I have a 99 F-150 with a 5.4 engine. Every once in a while my truck won't start. It turns over fine but just won't start. I've noticed that when this happens the Anti -Theft light is flashing, so i'm guessing the problem has to d o with this system. Is there any way to turn off this system or does anyone know what else could be causing this problem. this mostly happens if the truck hasn't started in a few days, most times if i turn the ignition on/off a bunch of times untill the Anti-theft light stops flashing, it will start fine.

 

No, you cannot simply remove or disable the PATS system.

You might try replacing the PCM Power Relay as they sometimes go intermittent and cause this symptom.

Other possible causes include: Multiple RFID chips on the same key-chain, intermittent loop antenna on the key cylinder, or some other wiring concern related to the PATS system.

 

You can turn off the PATS system but you need a tuner with a custom tune in it for your computer.
Or you would have to go to a dealer and get them to turn it off. If they would.

The guy that dose my tuning even emailed a guy a tune to turn it off. He was doing a 4.2 to 5.4 L swap and couldn't get the truck to start without turning off the PATS.

Phil

 

Had the same problem on an 01 Mustang with PATS.
Wound up having to replace the antenna assy that is part of the ignition switch.
Was not cheap