Have you broken a glass in the dishwasher recently? The cover to the drain pump is is located in the sump of the machine. Remove the large filter to access. The pump cover is domed shaped, about 80mm long and 50mm wide, slide the silver clip to the inside then pull the complete assembly out. (some water should flow back into the dishwasher. You should then have access to the drain pump. This pump should move freely (BE VERY CAREFUL IF GLASS HAS BEEN BROKEN) I think Miele might explain this better on their web site www.miele.co.uk owners section.
MC
January 2012