2003 Jeep Liberty 3.7L auto

Had a strange problem the other day. Cold out (-10C) so I went to start the Jeep to warm it up before driving home. Started as usual but died after about 3 seconds. Second attempt to start was the same. So I started it again thinking maybe it flooded and it started and ran as long as I feathered the throttle (just like it was carburated). As soon as I let off the throttle to let it idle, it would immediately die. First thought is the IAC system screwing up. BUT...the really odd thing about it was when the engine would die, the Security System lamp would continuously flash. Tried it a few times with the same result, it would stay running if you gave it a bit of throttle. As soon as you let off the throttle, dies and security light flashes. Drove it home by feathering the throttle so it wouldn't die. When I got home it did seem to idle ok.

And it has not thrown any codes.

Started it today and all seems fine. Any thoughts?