What does it mean when the sevice system stability message comes on? on 2007 Chevrolet Avalanche

I did buy the truck from the auction but, so far have everything down but the service sys stab, its been on all this time.

Asked by for the 2007 Chevrolet Avalanche
you will need to have someone run a diagnostic on this system to determine what codes are present. there are local
shops that have GM compatible software and the diagnosis
won't cost a lot.