Whirlpool appliances usually have a schematic included. It is large folded sheet and is usually tucked behind some grate or panel. On my dishwasher, it was behind the bottom kickplate. It is not component level for the PCB's, but it does contain troubleshooting and diagnostic procedures. For example with the dishwasher, which is 10 years old, the question was whether the problem was with the control panel switches or control board. Diode testing of the FFC showed the switches worked fine. That focused me on the control board for which there is/was a repair kit (2 relays and 2 capacitors). The relays are little cubes and upon disassembly the applicable contacts were badly burned.
Of course, your refrigerator may be different, but I would certainly search for that document. The Whirlpool site provided no help. I called and was told that Whirlpool no longer has "technical service." It is now called something like service clinic and has no live agents available. Everything Whirlpool wants to share is supposedly on YouTube. In my instance, the YouTube to which I was directed had nothing about troubleshooting. It only covered replacing the entire module, which was pretty obvious without the video.
I have had Whirlpool appliances for all of the 50+ years I have owned a house. I will probably be switching to Bosch or Miele if my repair fails again.