With the last few weeks have had SB lite and chime go off after stopping or during stopping turn off truck restart it all ok maybe for 2-3 weeks then happens out of the blue all ove. Had truck to dealer they said that they have had other owners complain off this and have not been able to find problem also said GM knows of this and they to have no answer. Is ther a fix to this problem or just keep shutting down and start it up again. Funny that I took truck on 2400 mile trip and no problems till I got off free-way and on city streets. any help would be great.

Ask your dealer to replace the brake light switch

I concur with Jgreenlees, brake light switch.

try sitting in the cab and pumping the braek pedal ( engine and key off ) every time you push the pedal the hydroboost motor should run, and the brake light come on, I be after a few repeated applications, they skip a few.

Took me 2 hours to figure out the first one, tested everything, even checked the relay to the hydroboost ( in plastic bag zip tied to brace next to brake master) came down to brake light switch. and have repalce dozens of them.

Kevin

Thanks Guys my dealers techs also did there own r&d and have come to the same answer replace the brake light switch they are also going to check out this website to.