A 2000 Ford 5.4L engine and transmission fell into my lap at the same time I was about to call it quits on my 79 Ranchero. But, what if I upgraded the Ranchero with the newer powertrain? There are a lot of obstacles to overcome. The biggest one may be the security system... or maybe there is an easy work around? I do not yet have a PCU. All I have at this stage is the engine and transmission from a 2000 Ford Expedition, a welder, a few hundred bucks, and a desire to bring the old Ranchero back to life. I figure I will need what little money I have to buy a wire harness, pcu, and fuel pump from the local junk yard.

Any ideas how to work around the PATS without buying an aftermarket PCU?

 

If the PATS system just do starter interrupt (no crank no start) and fuel pump power cut (crank no start) that would be easy to bypass. Unfortunately look at above description it mentions SecuriLock system (crank no start even if you bypass the starter interrupt). I believe it's possible to code it out and disable it. So wherever you buy the PCM from you might want to ask if they can code PATS out. If you look at the first 2 diagrams above on the starting circuit it doesn't show PATS gets involved at all.