Last winter (March and after), heater worked fine. But in mid-September its getting cold again, so I went to turn on the heater. Nothing but cold air was blowing out. I'm glad I have heated seats, since that's the only heat that can be provided.

I took it to the dealership, and they looked into it, and said that GM knows about it, and are working on a fix. But for now all they could do was to reset the programming to when it was first made, which they said is most likely only a temporary fix, and could last 10 days, 10 years... nobody knows for sure. Wondering how long it will take for the permanent programming fix, as I need the 4-wheel drive in my area during the winter, and with no heat, it's gonna be a cold one (assuming the temporary fix fails).