Plumbing Questions? Ask a Plumbing Expert.
My name is***** have been a Plumber for 15 years and was a plumbing Professor at UNM. The problem may be in the drainage have you made sure that the drain line all the way to the P trap under your sink is clear. The drain line from the dishwasher to the under sink drain should be easily removable and inspectable. It would be wise to also check the inlet underneath the sink and make sure that it is not clogged. If the kitchen sink is draining well then the P trap is clear. This would be my first next step.