You will probably want to replace the dishwasher.
This is most likely either that the pump has gone bad or the timer has gone bad (timers can go bad and only affect one cycle, but go through the other cycles okay).
By the time you find out which and buy the replacement part, you will probably wish you had just bought a new one.
Besides, if its one of the plastic tub one, that will likely be your next failure, and there really is no fix for that.
Just trying to save you a lot of aggravation.