Been getting this about 30-40 percent of the time when I start up, over the last week or so. Message will clear itself after a little while. Car will start regardless. Even got the message while I was driving the other day. That's when I decided to replaced the battery with a new Duracell. Today, got this message again (with the new battery). I keep the single key, in my left pant pocket, with nothing else (silence from the peanut gallery please). Same way I have been doing it since I got the car 1.5 years ago. So I don't think there is any interference. Looked at the owners manual as it states, and it gave me no additional insight.
I will try my spare key for a few days and see what happens.
Any words of wisdom out there? I'm still under CPO.
L