Air Brake Antilock Control Unit/module problems of the 2005 Buick Lacrosse

The traction control system lights come on during wet weather and or turning. The anti-locks brakes fail to work unless pressed completely down. No accidents have occured at this time, but a few close calls. The car is being returned to a gm dealer to inspect and report the problem. The brakes have always had a spongy feeling since date of purchase and since the brake recall was adjusted. I would hope that this problem can be investigated before there is a fatal incident since the anti-lock brakes become very non-responsive when the traction control system fails.