PATS Question

[99SportX]

I might be buying an Explorer or Mountaineer to use for a 5.0 conversion at the salvage yard. The problem I face is that the yard probably doesn't have keys for these vehicles. I want to be able to start the engine so I can make sure it runs, but have no clue how to start it.

Does the chip in the pats key comminicate with the lock cylinder in order to start the vehicle, or does it send a signal to the engine computer? If it is just the lock cyllinder, I could just remove the one in my sport and put it in my donor vehicle right? If it is the computer, will I have to get it reflashed at ford? I want to spend the least amount to get the engine started, so I was wondering if anyone knows how this system works.

Also, once i swap the computer into my sport, I want to be able to use my current key, so this is another reason why I am asking this question.

Thanks

 

[Jefe]

From another thread:

This is for PATS II. PATS I ('97) is more simple.

The PATS module sits on the data transmission lines (sorry can't think of what they call it) that come out to the OBDII port (as do a few other modules). So the PATS module and PCM communicate to each other via a serial link. In order for them to talk to each other they have to have exchanged ID's with each other back when they were programmed. In KOEO PATS and PCM exchange info to check ID's with each other. If they don't match both modules throw codes PCM is a hidden code, PATS flashes the Theft light). Assuming all communication is good, when you go to start up the car the PATS module checks the key transponder and communicates to the PCM whether the key checks out or not.

The PATS module can be programmed with the PCM ID by a locksmith with the proper equipment (as well as clear old keys or program in new keys) ($1,000 equipment). It can also be done with the proper sequence of key on, key off, pat your head, rub your belly sequence.

The PCM is a little harder. When a PCM is new (never been used) from what I can tell, the first PATS module it communicates with becomes the ID it stores. That way if your PCM dies, it can be replaced w/o the help of a Ford dealer with their $3,000+ progammers. If you put in a tuner chip programmed correctly before the PCM has this ID, then you can disable PATS for good. After the PCM has an ID, it is a bit more difficult. It seems that Ford is able to reprogram the PCM to accept another PATS module, but I never got this confirmed.

I tried to get Ford to put in a used manual computer (even offered to pay for a new one) and have them program it so it worked with my truck, but they declined saying they can't change to a different PCM from stock for emissions reasons.

Now I have thought about using my OBDII scanner hardware and programming some software to 'log onto' the cars serial link and monitor what gets transfered back and forth between PCM and PATS, and even researching what strings of code need to be sent to PCM or PATS to reprogram them correctly. But that would be a lot of work just to get my car to run with a manual computer.

In other words, this system is setup very well to prevent theft. And this is coming from a programmer/engineer Now there are ways to do it, but I won't get into that here for obvious reasons.

So in your case, You need all the 'normal' parts for an engine swap including the PCM. In addition, you will need the PATS module from the same vehicle. Since your vehicle is already wired for PATS, you will just need to swap out the PATS modules. Once that is done, call your local locksmith (who has a PATS capable programmer) and have him program your current keys into the new-to-you PATS module and you should be cool.

 

[99SportX]

Thank you very much Jefe. I never knew that there was a PATS module in the vehicle.

 

[CDW6212R]

Oh well, I guess my thought about your PATS won't help you to check the engine. Do you have one planned? Can you wait and find one with a key? Otherwise, will not the yard give you a guarantee that the 302 does run? If they do, then make the swap, and if it doesn't run right, then go back to them. Good luck,
Don

 

[99SportX]

Oh well, I guess my thought about your PATS won't help you to check the engine. Do you have one planned? Can you wait and find one with a key? Otherwise, will not the yard give you a guarantee that the 302 does run? If they do, then make the swap, and if it doesn't run right, then go back to them. Good luck,
Don

I won't buy it without a gurantee. That is a good point. I don't want to get screwed, because this will be a lot of money. I want to minimize downtime, as this is my daily driver, so I want to make sure everything works before i swap stuff. I expect that i could do this swap in less than a week if I work hard, but you never know. I need to have a driveshaft shortened at a shop too.