I've had to repair this appliance before, and it's almost always the motor-pump that needs replacing. It's a pretty easy fix if you have a roll out dishwasher. All you have to do is flip the dishwasher on its back, unhook the pump (no tools required, just push down the locking tab and twist and disconnect the wiring), and plug in the new one. I noticed that the tub wasn't draining completely either, so I replaced the drain pump as well just to be on the safe side. If, as I did, you let this project sit for a while before getting around to it, you'll probably want to clean off the turbidity sensor and run a couple of cleaning cycles with it empty to make sure you clear the gunk.