My dishwasher doesn't fully drain out the water from the tub. There is about 1/4 inch of water around the back of the tub at the end of the wash cycle.

Repair Steps.

1. I removed the filter frame, piston and nut assembly,sump cover and sump cap in the rear of the tub. There was nothing blocking them. I used a shop vac to suck out all the water and anything down in the sump area.

2. The Piston and Nut Assembly looked a little worn so I replaced it with a new one.

3. The Drain Solenoid arm moves freely and the piston slides up/down fine. I watched it engage during a test cycle where the piston was pushed down for about 30 seconds as the tub was draining. I also pulled it out of the unit to test it for resistance. I showed 37 ohms of resistance which my research says is correct for a good solenoid. I reinstalled it on the washer.

4. I removed the Check Valve & Body Assembly. The check valve looked a little worn so I replaced it with a new unit.

5. I checked the drain line where it connects into the garbage disposal and it was clear. I forgot to check the line coming out of the bottom of the drain pump before I reinstalled the washer back into the cabinet.

6. I did not test the drain pump as I don't know how. I do see the drain solenoid engaging and hear the pump pushing water as I saw the drain line moving back and forth so it seems like the drain pump is fine.

Does anyone know of another test I could be doing?

Is there a way to test the pump/motor assembly?

Is there a test to check if the control board is just shutting off the drain pump too soon at the end of the cycle?

The only thing I have left to replace is the complete pump/motor assembly and I hate to spend $128 on it and find it doesn't fix my problem.

Any assistance would be greatly appreciated. Thank You