I WAS DRIVING THE VEHICLE ON A HEAVY TRAFFIC HIGHWAY. ROAD CONDITION IS DRY, CLEAN. THE CAR IN FRONT OF ME SLOWED DOWN, THEN I PRESSED BRAKE. I DIDN'T FEEL ANY SPEED DECREASE SO I PRESSED THE BRAKE EVEN HARDER. I FELT THE BRAKE WAS VERY HARD EVEN IMPOSSIBLE TO PRESS DOWN, WHICH IS VERY STRANGE. BUT MY CAR STILL BUMPED INTO THE FRONT CAR AND STOPPED. THERE WAS SUFFICIENT DISTANCE BETWEEN THE TWO CARS AND I SHOULD HAVE TOTALLY STOPPED MY CAR IN TIME. I CONTACTED MY DEALERSHIP AND BMW MANUFACTURER IMMEDIATELY AFTER THE ACCIDENT AND SENT MY CAR BACK TO THE DEALERSHIP A COUPLE OF DAYS LATER. NOW BMW IS MAKING AN INVESTIGATION ON MY CAR TO DIAGNOSE THE PROBLEM. I HAVE NOT RECEIVED ANY DIAGNOSIS YET. *TR