The dishwasher would fill with water, and then was silent (during the time you'd expect to hear it washing. Cancel/draining worked fine too. I assumed it was the pump/motor that had failed. The dishwasher was barely 2 years old.
The repair was relatively simple. I removed the racks and spinners from inside the dishwasher. I turned off power to the unit and removed the hoses. I found it easiest to pull the dishwasher out of it's space and flip it on its belly so that I could get to the bottom of the unit. Removing the pump and motor assembly is relatively easy - just a couple of wires to unplug, and a couple of items to remove from the pump, and then you have to push up with some force to remove it.