Our Bosch Dishwasher was not cleaning the dishes at all. For the past year or so, while running it was emitting a high pitched sound while running, but we ignored it. I flipped the door latch so it would run with the door open. The water was so weak it wouldn't even turn the lower spray arm and no water was reaching the upper spray arm. Looked for any obstructions, but could not find any. While running, I removed the strainer stuff at the bottom and hesitantly put my finger in the hole where the water was being pulled in by the pump (not sure if that was really smart). I could feel the impeller turning, but noticed that I could put some pressure on it and stop it from turning. That didn't seem right. Found a Bosch repair manual online that described in detail how to disassemble everything so the pump could be removed. The impeller had separated so the half with the fins was not turning at full speed. Ordered a "Circulation pump repair kit" from Appliance Parts Pros and put everything back together. It's working better now than I can remember for a long time.