I have a 2003 Denali that has started giving the message "Stability Sys Disabled" then "Engine Power Reduced" and cutting your maximum speed to thirty miles per hour. The first time it happened restarting the vehicle had no effect on the problem. I took it to my local Chevy dealer, and his computer showed "no history" of an event. They could not find anything related to the message I reported. They did find that my rear suspension air compressor needed replacing, which I was already aware of, but I was told the two were more than likely unrelated. I went ahead and replaced the compressor, because I tow a large boat with this truck. A couple of weeks after this repair work the error messages happened again, and the engine power was reduced. I did a little research on the internet, and found that if I would disconnect the negative battery terminal for ten minutes, it would reset, and I could drive it at normal speed. This worked. The last time it happened, my son was driving it, and he was able to turn it off and restart it, and get it to return to normal function, which we had not been able to do either of the prior two episodes. Very strange. Any Ideas. I need to take it back to the dealer, but they haven't been able to make any headway.
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