Hello: I'm new to this forum, so forgive me if I'm in the wrong place. I have an 07 Chev 6.6 TD Duramax/Allison. I've had trouble in the past when going up high altitudes. The engine light comes on and stays on for quite awhile. After which, it goes off without coming on again. How ever Last year, It went on and the truck lost power and went into some kind of mode that would only let me go about 10 miles an hour. I was pulling my 5er so I pulled over, called On-Star and they told to me to turn the engine off and wait a few minutes. I did and sure enough the light went off and I continued my trip. When I got back, I took it to the dealer and they replace some sort of sensor. I hadn't taken the truck up any high places until a couple months ago, and then the light came on again but the truck ran fine. Got to the campground and the next morning the light was off and it never came on again. So my question is: Has this ever happened to anyone else? Should I take it back to the dealer. I there something else that can cause this problem? We're planning a trip up to Yellowstone in summer and I know i"ll be climbing some mountains, so I want to make sure I'm ok.
Thanks in advance for your help
Manny