remove the plinth from your kitchen units then the lower front panel beneath the door. you will need a torx bit. There are 2 tubes that allow stray drips of water to collect on the bottom tray of the dishwasher. If water collects here, and does not evaporate, it triggers a float switch to shut off the dishwasher. Sponge out any collected water, put it back together, and it should hopefully be back to normal.
rossi
March 2009