Q: Service Stability - Service Brake System on 2003 GMC Yukon XL Denali

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Off and on our "service stability" light and "service brake system" light will come on with a warning bell. Until last week, once we turned off the ignition, then turned it back on, it would take care of it.Now it stays on constantly with an annoying bell. We took it to a garage, they said they'd never seen this problem, since no code numbers were provided with the warning indicator. They suggested take it to a dealer. So we did, they in turn said they'd never seen this problem, not without giving dianostic code numbers. They asked for $300. and told us to bring it back after the weekend (we needed it) and they'd fix it for $200. more. Somehow I feel we might be getting ripped, especially since there has not even been a dianosis made. We have been told the problem will not present danger, but we can't stand the constant dinging bell. Hanve you heard of this problem?
(1) Answer
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: