This message light has come on in the past, when I've hooked on my trailer, but then it goes away when I hit "OK". Haven't noticed any problem with towing so, anyways I'm driving around Saturday night (no trailer attached, mind you) and all of a sudden, as I'm braking for a traffic signal, the stupid "Trailer Battery Not Charging" message appears and the annoying chime that goes with it. Foot off the brake, message/chime goes away. Foot back on brake, chiming stupid message. And it won't STOP! Even better, I put on my turn signal, same problem. Message and chiming until I cancel the turn signal. So I can't signal a turn or brake my vehicle without getting this VERY ANNOYING chiming and message appear. Just make an appointment with the dealership to get this checked out. Needless to say, I'm pissed at the inconvenience this is likely to cause since it's a hassle getting a loaner vehicle with towing capacity, which I must have in order to do my job.