Service Stability - Service Brake System

You need to get a proper diagnosis before proceeding. It's possible that the ABS/Stability module has failed and that's why they can't pull codes but if they are gonna be vague about what's wrong and how to fix it, find an independent GM specialist who may be more knowledgeable and care a bit more about you. I would call this a safety issue, I don't agree with the dealer there at all. Your conventional (hydraulic) brake system should be working OK but you don't have ABS or stability control, the vehicle was designed to have these systems active. If you want to find a specialist, here's a directory link for you: https://repairpal.com/gmc-repair-in-williston-florida

I myself have 2002 yukon gmc same issue but nothing wrong. Its a sensor that goes off when if your tire monitor may need serviced or just a faulty sensor. Aslong as you have checked your pads drums or rotars no surprise noises your fine. Its a bad sensor no worries. You can pull out the fuse and replace it or just pull the fuse all together. Just check your breaks and fluid if all is great you should have no worries.. but if you take it to a deal for codes they get you for a couple hundred just to tell its fine.. so far everything on my truck is fine its just a sensor gone bad.. hope this maybe help even though you posted this a awhile ago