If the cycle operates normally, but the unit doesn't drain, then I would suspect the pump.
If you remove the drain hose directly from the the bottom of the dishwasher (be ready to catch some water), sometimes you can clean the junk out of the pump and make it work again.... If not, it's right there and ready to be removed.
Answers & Comments
Typically either the timer switch or the pump.
If the cycle operates normally, but the unit doesn't drain, then I would suspect the pump.
If you remove the drain hose directly from the the bottom of the dishwasher (be ready to catch some water), sometimes you can clean the junk out of the pump and make it work again.... If not, it's right there and ready to be removed.
Good Luck!