1998 Mercury Sable • 150,000 miles

My theft light is flashing rapidly, somehow it is in "anti theft mode"
I have tried everything from unplugging battery for 7 hours unlocking with keyless entry, unlocking with key, turning the key forward once until theft light stops more than 3 times before trying again. I have noticed while doing this it blinks rapidly for about a minute then stops for a few seconds blinks once stops again then blinks 6 times a bit faster. Repeats this 10 times. Then shuts off but car will still not start. : ( Help! I didn't do anything to make this do this. The car was not broken into. Nor was anything touched. We filled gas to full. Then the next time trying to start it did this but start after a few times trying. Now it won't start at all
December 10, 2012.

In all likelyness the passive anti-theft system (pats) transciever is bad, that is a very common issue with these cars. It is located near the based of the steering column, near the ignition switch tumbler. Of coarse the only way to be sure is to hve a competent shop test it and see if it will prove out.(Test good)

Dec 10, 2012.