I looked up the ATP rule book online. The first code violation results in a warning. The second, in a point penalty. The third violation results in a game penalty. Further violations result in a game penalty or a default, according to the Tournament Supervisor's discretion.
I was surprised by that...I thought the fourth violation was an automatic default. Personally, on the fourth violation I think you should be locked in a room with Patrick McEnroe and be forced to listen to him gush about how great Andy Roddick is.