Kitchenaid KDTM404KPS F9E1 error

[dishwasherguy]

Hi! I have a Kitchenaid dishwasher (KDTM404KPS), giving me an F9E1 error, which the manual for my unit:

https://www.kitchenaid.com/content/dam/global/documents/202110/owners-manual-w11323304-reve.pdf

states: Dishwasher will not drain

When I start the dishwasher, it will hum and some motor runs and produce that error before the water fills.

If I pour a bowl of water into the bottom of the tub, and select the manual drain, it will drain right away. If I fill the tub and start a cycle, it will drain the tub, then hum and tell me it won't drain. But it just did!

I can go through the diagnostics cycles and they all work fine except for the 1st humming cycle which errors. If I skip that one, it will do the rinse and wash and drain cycles just fine.

The dishwasher is 2 years old, so I hate the idea of replacing it already, but I really have no idea what part might be broken to replace.

[hamhock75]

I had a similar problem with an LG. Pouring water in the tub and using the manual drain function it would always work. During a cycle it did drain but gave a drain error. 

This was the difference. During manual drain, it had no time limit to drain. During a cycle the drain time is on a timer. If it was still draining even though there was almost no water left when the timer expired, the error would occur. 

The problem was a failing drain pump which was too slow draining even though it was almost done when the clock ran out.

[dishwasherguy]

but wouldn't an empty tub fully drain quickly, even if the pump was slow?

[hamhock75]

I don't know if this will help but when I was troubleshooting my LG, I tried to determine how it knows if the unit fails to drain.

The only sensor I could see that could tell the machine there was still water in it is the turbidity sensor which measures the dirt in the water.

I would guess that if the turbidity sensor goes bad and gives a reading when there is no water in the machine at all, then the CPU might interpret that reading to mean that there is still water in the sump even though it is not  true.

[APPLIANCE DEAN]

I have seen an issue where the wash filter connected to the wash motor will get clogged with food and the unit will still drain but throw and error code because it is taking longer than designed to to drain. I will typically check that wash filter to see if it is clogged with a draining issue or washing issue on this unit. You can take the drain hose off of the sump and look inside to see if the filter is dirty.