I have the same problem
I have a new G6 Convertible that I bought in February. I never have left the lights on in my car because they are all automatic. My battery died 2 weeks ago, I was very upset because it happened only after a short time and now this light comes on. I called the dealer today to ask them about it and they thought I was crazy! They said they had never had that problem before but said I could take it to them on Monday and they would look at it. If you have figured the problem out by now let me know. If not, I can let you know what they tell me then.