Hello, I have a Kitchen Aid superba side by side refrigerator. Model number KSSC48QKS01. MFD date 09/02. Type B129/CB129.
About a week ago, the over temperature rest button started beeping and the red light was on. The temperature for the freezer was -10 F and the refrigerator about 50 F. I pushed the temperature rest button to stop the beeping, which stopped. But the temperature didn’t change. I tried to use the (+) and (-) buttons to change the temperature, and it would change and a few seconds it would go back to -10 F, and what ever the temperature is in refrigerator (now it’s 57 F because I’ve had the door open for a while working on it, but when it’s left alone all night or all day, it’s down to 46 or so) The freezer is cooling pretty good, things are a little more frozen than I like (especially ice cream 
rock solid)
Today, The first thing I did was clean the condenser coils on top of the refrigerator (and boy were they dirty, tried to get back and clean as much as I can) I also cleaned under the refrigerator.
I hear the freezer fan running(inside the freezer?), and cold air is coming out from the top vents. But the vent in the top part of the refrigerator, top left (Motorized Air door?) I don’t feel any air coming out. Plus I don’t really hear any fans in the fridge part. The condenser Fan on top is working and I can hear something working by the compressor side on top, but can’t see to know if there is a fan running or not.
I ran the diagnostics
01-Freezer thermistor: 01 thermistor is within normal range
02-Refrigerator Thermistor: 01 Thermistor is within normal range
03-Evaporator Fan Motor: at first it would be 02(Evaporator Fan Motor is on at incorrect speed) and a couple of seconds later it would change to 01 (Evaporator Fan motor is on at correct speed)
04-Condenser Fan Motor: 01(Condenser Fan motor is on
05-Compressor: 02 (Compressor is OFF waiting for minimum (7 minute) Off Delay 
06- Air Door: 01 Air Door fully opens
07-Bimetal/Defrost Heater:01 Defrost Heater is energized, bimetal closed. the
So at this point what should I do? is it an easy fix or should I get someone out to fix it for me? Thank you so much in advance for anyone’s help and comments.
sincerely,
Mike