has anyone had issues with the brakes? the braking assist turns on prematurely when I go to stop and lock up then loose power and get a loss of power message on the dash it does return to normal after a few minutes it happened when we purchased it on the ride home took it back to the dealer but being a Cadillac dealer they had no clue said it must have been downloading info , now it happened to my wife in the middle of a busy intersection scared the hell out of her any ideas?