I found the "Service and Wiring Sheet" folded up nice and neat inserted in a slot on backside of grill below the doors. (Go figure! Anyway, I removed the grill to inspect the heat exhaust coils. They were heavily coated with dust. They are clean now.)
Attached is both sides of the sheet for reference. I put my refrigerator in diagnostic mode and it never left step 1 (frig =0, freeze=1 and water filter =1)
Step 1 diag test is is labeled FC Thermistor. So I am going to replace that part next.
Results after part is ordered, received and installed.