Here is your parts
Model KUDI01ILBL3

Here is a tech sheet
https://www.servicematters.com/d...0Sheet%20-%208537797.pdf

Use the tech sheet and see if you can troubleshoot the unit.

If unit's timing is correct and it just not washing, then check to see if the wash motor is getting voltage when it should.
Could be something as simple as a broken wire where the cables go from the door to under the cabinet.

You are not really checking the timing you just want to see if you can get the wash motor to run.

Just go slowly through the tech sheet to see if anything just seems strange.

Could be you have something jammed in the chopper or impeller.
You will have to open it up to check this

I will look to see if I can find you some decent instructions

This may help if you get stuck
<title>Replacing Kitchenaid and Whirlpool Tall Tub Dishwasher Pumps

And this just for your info
<title>Kitchenaid Dishwasher making Noise

If the motor chopper/impeller turns easily by hand then it is probably either the motor itself or the capacitor

Do you have an ohm meter?
If yes, what type digital or analogue?

A meter will let you do some basic checking of the motor and the capacitor.
It will do a basic check and show some faults but will not do an absolute check.
I am not quite sure how to explain what I mean, as an example measuring the capacitor. It will check that the capacitor is not a dead short or that it is not an open and that it can take a charge. It will not check it at the operating voltage levels so if the capacitor is breaking down at a higher voltage, it cannot check this. Special equipment is required to do an absolute test.
Hope the above makes sense.

You can get a decent digital multimeter for under $20.00. You do not need fancy though it is nice if the leads are a couple feet long.
If it saves ordering one unnecessary part it has paid for itself and you end up owning a useful tool.
Most places will not let you return electrical parts so if you order it, you own it.
A couple things to watch when measuring ohms and continuity
1. Always remove power from the machine otherwise you could blow your meter.
2. Always disconnect at least one side of any device you are checking. This eliminates the possibility of measuring an alternate/parallel circuit path.
3. When checking for closed contacts and continuity use the lowest scale (Usually 200 ohms). Then try higher scales. This scale is 0 to 200 ohms so if the device you are measuring is 300 ohms this scale would show an open circuit which it is not, you are just measuring outside the scale's dynamic range.

There is a good STICKY at the start of this forum about it's use.