that make sense. But why is it only making noise when I reverse the car first and drive forward (eg reverse from garage, reverse from car space) not when I select drive straight away after I start the car? This exact same thing happens to me. Have to reverse first, then forward to get the "clunk". The longer the reverse distance, the louder the "clunk". (seems like this to me anyway... the volume is always different) If it's ABS self check, why does it only "clunk" when the car start moving forward? Shouldn't I hear the "clunk" even when the car is stationary? I have been to the service department to check it. But they said they heard nothing.