I have a Bosch SHE4AM15UC Dishwasher that won't drain and complete a cycle.
Short Story: If drain the water myself and start dry, the dishwasher appears fine and the impeller runs for 30 seconds continuously with no strange noises. If I start with water in the bottom, the impeller runs for 4-5 short bursts and then the dishwasher displays the clean light.
Long Story: When I start it, I hear the drain impeller try to run for 4-5 short bursts. After that the Dishwasher displays the clean light, like it has completed the cycle. The entire process takes less than a minute.
I opened the drain area and found some string and junk tied around the impeller. I cleaned that, closed it all up and ran another cycle. This time, I heard the drain motor run consistently for around 30 seconds, instead of short bursts (the was no standing water, so the impeller didn't have any work to do). The dishwasher then successfully moved onto the next part of the cycle. I thought I fixed it.
I stopped it, to restart the cycle, this time with water in the bottom. Again, 4-5 short bursts from the impeller, and then the clean light. So it's consistent, it works with no water in the bottom, but fails when there is water in the bottom.