Leets

Well, I did a search and couldn't find a solid answer so I hope someone can help me out. My car's been spending the day at the dealership today, and it turns out that my IACV is sticking (the usual problem). Now, my car's still under the 6 year/70k mile warranty on powertrain and related components, but the dealer told me that I'd have to pay out of pocket for the IACV work. Is this accurate? Isn't the IACV part of the powertrain?