You can test the three-way valve separately. Both the coils and the valve operation can be tested. See tech sheet schematic and test 4.
Lots of service bulletins on this model. There was a big problem with evaporator leaks. If the freezer is somewhat cool or has a partial frost pattern, you probably have a sealed system leak.
You should post question like this– having to do with problems in specific model– at Appliantology.org. That’s our tech support site. You can get a tech membership at Appliantology and download tech sheets, service bulletins, and service manuals: https://appliantology.org/topic/66390-tech-memberships-at-appliantology/