DRIVING FROM SKI AREA IN LINE OF CARS AT 15MPH WHEN CARS AHEAD STARTED TO STOP. HAD "SNOWFLAKE" BUTTON PUSHED. BRAKES APPEARED NOT TO ENGAGE, PROGRESSIVELY PUSHED ON BRAKE HARDER BUT NO EFFECT, FORTUNATELY BY THE TIME OF IMPACT CAR HAD SLOWED TO 5MPH AND AIRBAGS DID NOT DEPLOY. DAMAGE TO FRONT GRILLE. TURNING OFF "SNOWFLAKE" (ABS) RETURNED BRAKING TO NORMAL. *TR