Inside the pump housing there is the Protector (number #8 at the diagram#9)located at approximately 7 o'clock.Check if it's plugged.
Check the wash arm jets and feed tube at the back for any blockage.
Check the water level. Add few cups of water during the wash.
If the problem is with the level of water, check the screen inside the water valve.
Here are the breakdown diagrams and http://www.appliancepartspros.com/pa...del_id=5141714
Thank you. Post the results.