Do you hear the fan running in the refrigerator section?
I'm attaching your tech data sheet below.
On page 1--->Control Board Troubleshooting--->Accessing Service Mode
DO--->Service Test - 57 R
(Compartment) Fan Test
• When entering service test, the Refrigerator Fan turns on. The display shows “ON.”
• When leaving service test, the Refrigerator Fan turns off.
Here's the RC fan motor in the refrigerator section for your model:
Cover-evap W11395558 / AP6980049 made by Whirlpool
If its just humming and not running it might be jammed with ice/frost or completely just bad.
You can remove the back panel inside the refrigerator and check for ice/frost jamming it up.
Here's the repair manual: https://drive.google.com/file/d/1iRRnn103aeGMfrJwdW0Qoazg6S6k2qho/view?usp=sharing
Page 3-7 tells you how to remove the Evaporator Cover Assembly, and the RC fan motor is mounted on the backside of that Evaporator Cover Assembly.
Its quite a job to do, if you plan on doing it yourself allow yourself plenty of time. If your leery of doing it or don't have the time to do it, contact KitchenAid at 1-800-422-1230 to come out and do it for you.