This seems to happen to my car about every 6-9 months. I pull the cover for the BCM thats by the passengers left foot. Take off both BCM connectors, put them back on and the problem is gone again for another 6-9 months. Just seems to be "one of those things" that you figure out and deal with. No big deal.
Don't waste your time taking it in to the dealer. A 5 year old could unplug and plug in the BCM connectors. Just do it and the problem goes away. If you have some dielectric grease, smear a little on. I don't, but still fixes the problem.