I have a 2004 Avalanche. Driving home from work about 2 weeks ago,(which is a 1hr & 10 min drive), all was normal and I was driving @ 60-65 mph on I-20..when all of a sudden I looked down & my speedometer said 120!! I said what the@#$!?...I was close to the dealership where I purchased the vehicle so I pulled in at the service dept. When I turned the truck off, the speedometer was reading 50 (poor thing couldn't make it back down to 0). Showed the service guy & told him what happened. He said he had heard about some speedometers sticking and maybe could replace it up to 70,000 miles but I have 122,000 on mine (hadn't heard about that & mine just started.) I asked what could be done-he said I could replace the instrument panel which would be $500-600 dollars or I could just reset it by turning it on & off. Well, I took the later but you can do that but so long. Went on the Trailblazer forum & saw they are having big time problems with theirs-maybe they stuck a Trailblazer instrument panel on mine.....Has anyone else with an Ava had any trouble with theirs?