Intermittent temperature fluctuations in fridge and freezer

Hi @krp663

Has the refrigerator an ongoing small Freon leak or has it been fixed?

If it hasn't been fixed this can cause inconsistent temperature fluctuations to occur. It should really be fixed first and then check what the temperatures are like.

If it has been fixed, I assume that the service techs ran the diagnostics to check if they showed up anything and nothing was shown?

The mini manual for the refrigerator shows that is uses the adaptive defrost cycle method i.e. occurs once every 60 hours (accumulated compressor run time) and lasts for 40 minutes if the doors haven't been opened during this time. If they have it occurs more often.

To me it seems as though it's the freezer temperature sensor (thermistor) that may be the problem or it's the control board, as the refrigerator temperature seems to mainly vary between its upper and lower preset values although occasionally it is too cold but not the freezer as it gets colder and warmer than it should.

If the freezer gets colder than it is supposed to, this may also impact on the refrigerator temperature as can be seen on the air flow diagram in the mini manual..

According to the mini manual, the temperatures can be varied between 32°→ 42° (Fridge) and -5°F → 5° (Freezer). However, the compressor should be stopped when the temperatures reach their pre set minimum temp values and only start again when they exceed their pre set maximum temp values.

If it continues to run once the minimum temperatures have been reached you may have to check the thermistors (I would check both, refrigerator and freezer) to see if their resistance value is reflective of the actual temperature.

Here's the technical service guide that is also applicable to your model. On p.37 it shows the resistance values for the thermistors at given temperatures.

On p.53 it shows how to enter the diagnostic tests. Run test # 0 7 to check if the thermistors test OK. To me a "pass" may mean that they fall within a certain tolerance range but this may not be that accurate. The only way to know is to actually test them with an Ohmmeter on the control board J1 harness cable plug pins with the cable disconnected from the control board. The mini manual shows which pins are used for which thermistor. (FF = refrigerator, FZ = Freezer).

Note the temperatures in the compartments, disconnect the power from the refrigerator, unplug the J1 harness cable from the control board and then measure each thermistor's resistance to see what "temperature" they're signalling to the control board

If the thermistors test OK i.e. resistance value = temperature as indicated just before testing, then it may be the control board

If you find the problem and it is a faulty part that needs replacing, here's the parts list that is useful. Locate the wanted part in the list and note the manufacturer's part number shown for it. Search online for the part number only, to find suppliers that suit you best.