Maytag dishwasher not draining last inch of water

I've got a maytag dishwasher and it has decided that it no longer wants to drain the remaining inch or maybe inch and a half of water from the bottom once it has finished it's cycle. I took apart the bottom part where the screen and such are. there was a little bit of debris there, mostly mineral buildup(the white chalky stuff). I removed a little shroud to find some sort of grinder. It was a wheel and blade. Anyway, I didn't see any "aHA!" stuff there, and that was all that was able to be taken apart. So, I cleaned everything out and ran it again - same issue. This dishwasher, despite it being one of the most expensive models they sold in the store, has been a complete piece of junk. I had to replace the main circuit board behind the buttons when it was just barely over a year old, and of course, Maytag was quick to point out that it was no longer under warranty.

Any thoughts on what I might look into now? I'm stumped!

MAYTAG MODEL: MDBH989AWS3
SERIAL: FY5202616

 

Maytag aka Whirlpool has been ignoring the defective keypad membrane for years. The actual membranes were defective from the manufacturer/supplier yet they denied all knowledge of a problem.

Your problem is the drain path is not clear. Drain is a timed function so if it doesn't drain at the correct rate there will be water left behind.

 

OK, thank you for the response. It would make sense what you are saying about the timed function. It's odd that I can hear the dishwasher draining into the garbage disposal. I looked under the dishwasher and the hose that comes from the drain is clear, so I can see into it. It is filled with liquid but I don't see any blockage. I will take it off of the dishwasher and blow air through it to make sure it is completely free. Is there somewhere between that food grinder and the drain hose that cannot be seen? Is it possible that the blockage is not able to be seen?

 

They've replaced the drain pump with an improved impeller design. You need to pull yours out to check for blockage in the volute. The video below is replacing the pump but is useful to see how it's done.

you tube/watch?v=dMzxepj48l8

You can find exploded parts views at this link. You'd click on "pump and motor" tab. The drain pump is part # 15. (OEM # WPW10348269)

Maytag Dishwasher | Model mdbh989aws3 | Sears Parts Direct

 

Thank you. You've been incredibly helpful!

 

Just to add, ensure the drain line has a high loop or an air gap. This is the only way to ensure the hose drains as completely as possible and creates a vacuum break in the line.
Here's a quote from GE, I have many others:

GE: “If an air gap is not required, the drain hose must have the high loop from the floor to prevent backflow of water into the dishwasher or water siphoning out during operation.”