I think I know how to solve your problem. The pressure switch that controls the water supply valve can be accessed from the rear of the dishwasher. Take off the panel that is on the left, viewed from the rear. The pressure switch will be at the upper left with a two part tube leading down to the water sump area. Take the tube apart and clean it out. Any clog is most likely in the lower area, larger diameter tube. When you have the 'clamp' removed, you can pull the large tube off the reducer fitting. If the reducer fitting does not have any debris itself, you probably don't have to disassemble and clean out the upper part of the tube, but you could just to be sure. The first time I had this problem, I just blew out the lower tube. This time I really cleaned it out. To clean the lower part of the tube I used a doubled coat hanger wire. I straightened the tube and inserted the doubled wire, rotated it a few times, and pulled it out. It was covered with gunk. I actually repeated this process several times until it came out relatively clean. I reassembled the dishwasher and it is back to working fine.