1996 GT PATS problem

SNVitty

New Member
Mar 8, 2019
2
0
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Austin, Texas
Hi,
My name is Corey, I'm new to the forum and looking for pats help! I have a '96 gt convertible and I'd like to try to figure out why it's not reading the key.

The Story
I was suffering from denial. I have a 94 f150 running a 351 with ported heads, intake, long tubes, true dual, 4 inch lift, 33in A/Ts, and a few other goodies... and a certain lead footed driver. I was certain I was getting 30 mpg driving all over Texas. Turns out my estimate was slightly off.
I have since come to accept that honesty with ones self is important. I decided I needed a more efficient vehicle. While shopping around I found the perfect solution! A brand new to me 1996 gt convertible! (3x the mpg!) I talked the seller down to $400 because it didn't start and they couldn't figure it out. (In my head, at $400 I could get it and swap in a 302 if I got tired of messing around with the 4.6.) The only thing is the car doesn't run and the theft light flashes.

What I have tried.
At first the car wouldn't turn over, and the fan was constantly running. Figured that out and swapped the CCRM for one that I know works. Something still wasn't right and I pulled the ecm to have a look at it and found out it was for a crown vic with an automatic. :cautious:

Swapped in a proper ecm, put in a new fuel pump and a good test battery. Everything seems to be working well, the car even turns on and runs for a second. However the car won't stay on and the theft light flashes. After some digging I believe it's the PATS.
I have tried swapping the transciever and the pats unit itself, I have had a locksmith out with a full diagnostic system, tried different keys, all to no avail.

From what I know thus far...
The PATS (Which is type A) is not reading a key. *Note: NOT THAT IT SEES THE WRONG KEY BUT THAT IT DOESN'T SEE A KEY AT ALL. From my research I can tell that it sees no key because the light doesn't flash for 15 minutes (so I can't reprogram it). It only flashes for 60 seconds.
I don't want to need an SCT tuner to use my car at all, but I will if I have to. I have searched so much for the last 7 months and have found no real information for how to address this specific problem. I was wondering if there is anyone that can help me out.
 
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wmburns

SN Certified Technician
Aug 14, 2009
5,849
506
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Houston Texas
Do you have an advanced ODB2 scanner? One that is capable of monitoring and graphing PID's as well as able to talk to other body control modules other than the PCM? If you did, it might make real short work of your problem. As well as helping you with every diagnostic session afterwards.

Here's some information on an affordable ($30) Windows based unit.

ForScan ODB2 scanner w ELM327 USB
https://www.stangnet.com/mustang-forums/resources/forscan-odb2-scanner-w-elm327-usb.57/

An added advantage is the possibility of providing a DIY PATS reprogramming option. But most importantly an advanced ODB2 scanner will take the guess work out of what inputs truly are being understood by the PCM.

Here's some information on how to re-program the PATS key as an end user. However as you have mentioned if the key is not being read at all, this will not work.

96-97 PATS key re-programming procedure
https://www.allfordmustangs.com/forums/4-6l-tech/1076417-96-mustang-gt-pats-issue-please-help.html

Do you have a Ford Factory service manual and wiring diagrams? In Section 13-11B: Anti-Theft System, Passive there are a series of pin point test that gives step by step instructions on how to test and validate the various parts of the PATS system. To effectively use many of the pin point tests needs an advanced ODB2 scanner to monitor the various PID's.

If interested in getting a copy of the Ford service manual and wiring diagrams for your model year car I may be able to help. PM if interested.