I have the same thing happening to my 2000 GMC. Had it to the mechanic twice. First time he put it on the computer, but couldn't find anything wrong. Through the computer he fixed the light for awhile. It came back on a few weeks after so back to the shop. He tested it again. He said the brakes are fine, but the light may need replaced. When we get the time that will be done. As of now it is a minor annoyance.
