Whirlpool dishwasher won't Drain

Dishwasher Repair
1

The water in the basin will not drain. I checked the overflow vent and it is free of obstruction and the water flows freely from the drain through the connected hose. I am wondering if the pump to push the water up and out is the problem. What to do?

I checked the diagrams for the washer, but am not sure what to do next.

got help?

THANKS!

2

Here are your parts
Replacement parts for WHIRLPOOL DU840DWGX2 | AppliancePartsPros.com

Here is a manual
https://secured.whirlpool.com/Service/SrvTechAdm.nsf/2cd44500d572193285256a45004fd9d6/56e33eb0e839a7fa85256a8e00510938/$FILE/4322430.pdf

Could be something as simple as a stuck ball or flapper valve.