After numerous searches I still can't come up with a definitive answer for 98 key programming. I just bought my car with 1 key and of course need another. I have one coming, but need to know if I can do this myself. Some say you only need 1 key, the owners manual says 1 key, but others say you need 2 keys for a 98. I need 98 owners that have programmed thier own keys to chime in please.

:L

From F150NET (http://www.fordf150.net/howto/patskey.php)

If you want to add a key....
**You must have two original keys to perform this procedure. If you only have one key, you WILL have to take it to the dealer to get it programmed**

1. Insert and existing (working) key into the ignition cylinder.

2. Turn the ignition cylinder ON (RUN) and back to OFF. Ignition should stay on for at least ONE SECOND.

3. Remove the existing key and, within TEN seconds, insert a second working key and turn it to ON (RUN) and the back OFF. Ignition must be in ON for at least ONE second, but no more than TEN seconds. Remove the key.

4. Insert the new key before TWENTY seconds have elapsed and turn it to ON (RUN). Leave it the ON position for at least ONE second and turn back to OFF.

5. The security light will light up for THREE seconds to indicate that the new key has been successfully programmed.

6. To program additional keys, repeat steps 1 through 5


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As a precautionary measure for all of the above procedures, you should wait at least one minute after you have performed this until you start your vehicle

This site (http://www.1-800-pdq-keys.com/news.htm) explains the 97 vs 98 PATS systems.

Thought I would update this thread. Just got my spare key today and went by what the owners manual said. Put in my good key, turned it to on then off. Pulled that key out and put new key in and turned to on. Theft light on for 2 seconds then went out. Turned key off then tried to start car. Started right up!! Hmmm..... 1 key and it worked. This car was built in 3/98 so it's not like it might have had the 97 system in it. Guess I got lucky, anyway I'm happy didn't have to take a trip to Lincoln.