I had the same fault, which turned out to be a stuck impeller on the main motor.
I managed to free the impeller by dismantling the dishwasher, removing the main pump and soaking the impeller with WD40.
When I asked Zanussi about the price of a new motor, they quote £93 (inc of VAT & delivery), which I think warrants buying somebody elses dishwasher next time round. Never been impressed with this machine, and it too died within 3 months of the warranty expiring.
Robin, March 2005