you have an obstruction before the drain pump clean the sump pump area out inside the dishwasher of and clogging. Remove the drain hose off from underneath the sink and put it into a bucket and watch the flow as it's coming out it should be enough water coming out to pump it in less then 3 minutes in most cases. Also check to see if your hose is kinked or underneath a unit and inspect your drain hose throughly i've seen small objects clog them take the whole hose outside and take your garden hose to it to clean it out. If it's a black hose connection at your drain pump spray the hose both ways to clean it out. If it's a red connection at the drain pump it has a flap and you can only spray it outwards from where it connects to the drain pump. If you have it hooked up to an air vent at the top of the sink those are also the culprits alot of times clogging up take the cap of that off if you have one and clean it out. Good luck