Replaced drain pump. did not fix problem... replaced drain hose from pump and fixed problem.
Pump can be replaced without removing dishwasher so that was my first try to fix . When that did not work , I had to pull out dishwasher and noticed drain hose had a hole and was partially plugged. I replaced the hose and it was just like new. Drain hose is on left side of my whirlpool dishwasher, so I had to pull dishwasher out to see it.. Note on this model whirlpool the back flow valve is in the drain hose. Mine was not plugged or broken . Flushed all other hoses while I was behind dishwasher just to make sure.
Saved me a service call and cost about $100 in total parts which beats a $600 dishwasher.