Has it had an airbag recall? The demonic possession is probably related to the clockspring, or a module plugged into it. If I recall correctly, the clockspring gets replaced with the airbag recall and you might get it all fixed for free at a dealer, so look up your VIN and check for the recall.

 

I seem to remember my clockspring being replaced twice. The first time was for a recall for a dust shield, IIRC. The second was under this special warranty when my horn wouldn't work. I was just before 150K miles on the Wrangler, so took care of it just in time ...