WHEN APPLYING THE BRAKES TO STOP THE VEHICLE HAS SPONTANEOUSLY ACCELERATED TO A VERY HIGH SPEED EVEN THOUGH YOU ARE STANDING ON THE BRAKE WITH BOTH FEET. THE BACK WHEELS ARE SPINNING OUT OF CONTROL, BURNING RUBBER, AND YOU HAVE TO PUT THE VEHICLE IN NEUTRAL AND TURN OFF THE ENGINE. IT HAPPENS INTERMITTENTLY AND HAS HAPPENED SEVERAL TIMES (ALL ON CITY STREETS). WE HAVE HAD TWO DIFFERENT MODULES REPLACED (DON'T REMEMBER WHAT THEY WERE CALLED) AND IT CONTINUES TO HAPPEN.