We're having same problem with our whirlpool GOld quiet partner III. We moved into our house three years ago and no manueal was left. I am sure its a filter or plug but I can't seem to figure out how to get to the filter or plug. I can take off the arm but then nothing. Is there a manuel I can get or can someone explain exactly where the parts are that I need to check? Dishes have grit on them, white spots, just not clean at all. Thanks!

Question edited for a lot more clarity.

https://www.applianceblog.com/mainforums/threads/quiet-partner-iii-d3-error.48241/

Also, motors buzz when the start/run capacitor fails. See if you can located where the buzzing is coming from.

https://www.google.com/search?q=Whirlpool+Gold+Quiet+Partner+III%2C+D3+error

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Es posible que la luz Soak & Clean del lavavajillas Whirlpool Gold Quiet Partner III no se encienda si el lavavajillas no est? recibiendo energ?a o si el lavavajillas no est? en el ciclo correcto. Se recomienda verificar la fuente de alimentaci?n y asegurarse de que el lavavajillas est? enchufado y reciba energ?a. Si la alimentaci?n est? conectada y el lavavajillas est? en el ciclo correcto, entonces es posible que haya un problema con los circuitos o el cableado del lavavajillas. Se recomienda ponerse en contacto con un centro de servicio autorizado de Whirlpool para obtener m?s ayuda.

There are many places and parts for dirt to remain after washing. Clean all parts as per manual. Spray inside with vinegar and lemon juice, place tablespoon of bi-carb soda in dispenser and put through cycle without dishes

TRY A RESET CODE
Press the "Sani Rinse," "Heated Dry," "Sani Rinse" and "Heated Dry" buttons on the dishwasher's electronic control panel in quick succession to put the appliance in diagnostic mode.
Close the dishwasher door and engage the door latch.
Wait 10 seconds before pressing the "Cancel" button to reset the dishwasher.

This is a bad wash pump. Looking at about $175 for just the sump assembly. You could do it yourself, but unit would need to be uninstalled.

Our whirlpool gold quiet partner iii dishwasher is not working well . It is not gettting dishes cleaned soap left on dishes on top primarily

Inspect for plugged drain screen. Sometimes you have to take apart the bottom area for access...

Thermal fuse mounted to the control board see if you have power on each side of it checking from post to ground,if you got power going in but none going out it's blown,and has a more serious issue somewhere.

Yes, you almost certainly have a Whirlpool Gold Quiet Partner III Model #8575637
Of course the great news with buying from Costco is the ability to return products you are dissatisfied with. Check with the customer service desk.
Please reply if you want to to get into repairing it and we will get under way.

the cap doesn't come off, you just have to open the door all the way. then, when you pour the rinse aid into the dial area, it will get sucked into the dispenser. but if the door isn't open all the way it won't go anywhere and will overflow on you.