[kavatski]

If you're in gear and stepping on the brake, you may hear a beep and see the slip indicator light flashing. This indicates that Hill-Start Assist Control (HAC) has been activated. This feature is supposed to keep the brakes applied for two seconds to prevent the car rolling back on a hill while you move your foot from the brake to the gas. You turn on HAC by pushing on the brake harder than usual.

However, HAC will only work if the vehicle is in gear - not in Park. If you're certain that it's doing this when you're in Park, it sounds like a problem with HAC coming on when it shouldn't.