With cruise control engaged, upon cresting a hill and starting downhill the vehicle stutters as if it doesn't know whether or not to give it gas or idle downhill. It occurs around 55 mph. Vehicle is 2004 Chevy Trailblazer, 6-cyl. This problem identified withing 2 mos. of purchase and dealer found nothing wrong. Any thoughts? tnx...carlton

 

I do not know, but my 04 GMC Sierra does the same thing. Does the truck have a mind of its own and to keep a set speed will it apply the brakes to maintain the speed? I am glad I was reading and seen this post, because I have been meaning to mention it, but have been to busy to do it. And mine occurs normally around 65 to 70 MPH after cresting the hill top too and going down hill.
Why can't it be like my 1990 model and just speed up going down hill andlet me passpeople until it levels out and returns to the set speed after it slows back down?

 

Thanks for posting your similar experience. My mechanic could not fix it, if he event detected it. The problem has been around since the Trailblazer was purchased new. As it gets older, maybe it will become less evident.