2009 Yukon 2500 Integrated brake controler

[evsjr]

I parked and winterized my 2007 27 FB classic last September 2008. In December I purchased a 2009 Yukon 2500 with heavy duty towing package with the GMC integrated brake controller. The trailer had been doing fine with a Prodigy controler (which I still have) when I parked it. Yesterday I did a test hook-up to make sure the Airstream and Yukon were compatable. The intergrated controller did not recognize that a trailer with electric brakes was hooked up. Other connector functions (turn signals and running lights) were fine. The controler would not engage the brakes in any transmission setting, gain setting, or with the manual lever. In short, I don't have any trailer brakes. Needless to say, I parked and un-hitched.

My first stop will be to have the integrated brake controller checked out by a GMC dealer..... hoping that I still have one in business under th "new GM." If GMC says there is nothing wrong with the truck, what next??

Does anyone out there have any experience, good or bad, with similar rigs? Any information will be more than I have now.