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Juan Crespo
Juan Crespo, Tech Trainer
Category: Ford
Satisfied Customers: 1526
Experience:  A.S.E. Master Technician, Advanced Level, Emissions - Asian, Domestic, & European
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I just replaced the Timing chain on my 1998 Ford expedition

Customer Question

I just replaced the Timing chain on my 1998 Ford expedition and now it will not start. The Theft light is flashing fast.
The starter motor activates and I have spark on all cylinders but no signal to the fuel injectors. If I spray starter fluid in the intake the truck starts right up for a few seconds and sounds fine.
I suspect something wrong with the PATS system, and have tried to start using all my keys with no luck. I want to be sure before I go to the dealer to have it looked at that I did not miss something simple.
Submitted: 1 year ago.
Category: Ford
Expert:  Juan Crespo replied 1 year ago.

Hi there. Welcome to our site!

I myself cuss and swear at every vehicle I work on - no specific reason, just because it feels good :-)

Now, to the matter at hand; going by the symptoms you describe, the PATS is active. This can be caused by a damaged key, a non-encoded key, bad wiring or bad PATS module.

Being as it is an anti-theft system, it cannot be defeated or bypassed using regular methods. Any trouble codes in the system's memory can only be retrieved by an NGS tester or similar scan tool.

Obviously, the first thing to try would be a working spare key. Do you have one available?

Customer: replied 1 year ago.
All keys have been tried with no success or difference in symptoms. I have a code reader and no codes are being shown either.
Customer: replied 1 year ago.
I forgot to add. The fuel pump does activate. the fuses are all intact on all fuse boxes and the pump relays are activating. The fuel injection rails also have 32psi. I even swapped the relays to see if the problem would follow a relay. No luck
Expert:  Juan Crespo replied 1 year ago.

I hear you, Brother. I'm just not sure you're hearing me: you need a NGS tester to communicate with the PATS module to retrieve any codes and see what the real issue is. PATS has nothing to do with OBDII, so Ford is not obligated to make PATS codes or data generic - OBDII generic codes and data are the ones you can get with just about any good code reader.

By what you just posted, PATS is preventing the PCM from pulsing the injectors open - if you were to plug in a Noid light into any injector connector, you would see it would not flash as the engine was being cranked by the starter.

Licensed locksmiths usually have access to special scan tools that focus on anti-theft/lock systems. Know one of those that could you ask for help?

Customer: replied 1 year ago.
I did see exactly that with a noid light. I just want to confirm it looks like a PATS issue and not the PCM or some other thing. There seems to be no clear answer about PATS symptoms. some say PATS will not allow the starter motor to work, and others say the starter will activate but no fuel injectors.I know the PATS codes are not OBDII. I just did not want there to be any question that there may be a code, or codes, being displayed as part of my previous repair.Also, Unfortunately this repair took me longer than expected and the battery was unhooked for about 8 weeks. Not sure if this could be an issue as well.I have no problems contacting a locksmith, or the dealer to get this resolved. I just want to be sure it is done right the first time and parts are not replaced unnecessarily.
Expert:  Juan Crespo replied 1 year ago.

Well, I think I can clarify things a little but better for you:

Ford states this to describe PATS:

"During each starting sequence, the encoded ignition key is interrogated by vehicle anti-theft electronics. If the key's identification code matches code programmed into anti-theft system, vehicle is capable of starting. If key's identification code is incorrect or missing, vehicle is prevented from starting."

Since PATS uses the PCM to prevent the engine from starting, and the PCM is not part of the Starting Circuit, you can safely say PATS is the cause for the no-start on that Expedition you've been working on. Furthermore, there is no associated procedure that could cause PATS activation other than disconnecting the battery.

Unless you purposedly damaged the key or messed with the wiring, I got to say you are not a fault here, Brother.

Best Regards.

Customer: replied 1 year ago.
Thank you for the PATS clarification. It does help.I guess what I am trying to find out is this going to be a new PCM? It was fine before I started this project and the only thing I can see that caused it was the battery being out for too long. Or is a simple reprogramming of the PATS system by the dealer going to fix the issue?Before I pay to have the car towed. it would be nice to know what to expect.
Expert:  Juan Crespo replied 1 year ago.

Going by what you have posted, I can't see where a PCM would be needed. What makes you say that? Did you do something that could have damaged the PCM? Am I missing something (a senior moment perhaps ;-)?

At the same time, I can't say for sure a simple reprogramming of the PATS system by the dealer is going to fix the issue. Once again, am I missing something here?

Customer: replied 1 year ago.
I am trying to eliminate the PCM as a culprit. I am hoping for something simple like re-programming
Expert:  Juan Crespo replied 1 year ago.

Well, my friend, in my role as a verified expert on this site, I have tried to give you not only the advise you were looking for when you posted your request, but any additional information from the manufacturer that would seem related to this issue. Other than that, I don't know what it is that you expect from me.

What would be your technical explanation for needing the PCM re-programmed?

Best Regards