We are getting a "Call Repair" alarm on our fridge that is about 6 years old and has been working very well. It is still working well but is getting this alarm. The only symptom that appears to be changed is that we are getting ice/frost buildup on the back wall behind the 3 shelf in the refrigerator compartment.
We have reset the over-temperature alarm and the water filter alarm but the "Call Repair" alarm continues to ring.
I have also taken the top grill off and vacuumed dust and lint off the upper coils.
Any further suggestions??

Refrigerators - KitchenAid - Architect KBRA20ERSS Bottom Freezer Refrigerator