GFE29hsdcss GE fridge displays 34 degrees when it's 39 - have tested thermistor and replaced control board

[kkrep]

GE Fridge purchased 2014.  GFE29HSDCSS

Current issue is that the displayed temp is not the temp inside as measured by other thermometers.  Test of FF thermistor in ice water and then running the diagnostics shows me that it is measuring correctly (33) as is the thermistor by the evaporator. Last year I replaced the control board and I have previously replaced the FF evaporator fan.  The FF defroster is working fine through the diagnostics test.  Fridge seems like it thinks that 39 degrees is actually 34 degrees.  Turbo Cool function stopped working ages ago but I haven't found any instructions on how to even test it, let alone what could be wrong (press button, tc displays, no cooling kicks on).  Freezer has had no issues, as far as I can tell. 

If I reset the breaker (which is a tip I read), the temperature display actually shows the correct internal temperature and all of the cooling kicks in and it seems to cool for a bit until an hour or so, when it goes back to displaying 34 for the fridge temp when it's 39 or so.  This actually worked twice.  

Any thoughts on what's going on will help me with next steps (curb it or fix it).  Is it possible that the thermistors would measure correctly in testing and then not send the right data to the control/display?   

Thank you,

kkrep

[Vance R]

This refrigerator has 5 thermistor - ambient temp, freezer temp, freezer defrost, refrig temp, refrig defrost. If the thermistor you test is on the evaporator that is the defrost thermistor.  Looks like the refrigerator thermistor is in the ceiling of the refrigerator section, item #956 in the exploded parts view. 

[16345Ed]

+1 for FF thermistor being suspect. 

[16345Ed]

On 4/27/2023 at 3:31 PM, kkrep said:

Test of FF thermistor in ice water and then running the diagnostics

Did you measure with your meter or just run diagnostics after putting in ice bath?

[16345Ed]

Would also test FF thermistor at room temp with a meter. Reading a thermistor at 2 temps is really a more accurate test. 

[kkrep]

Thanks for the responses. 

I tested the FF thermistor (fridge, up top in the ceiling) in an ice bath still connected.  Water temp 34 and display on the diagnostic for it at that time also 34, which say to me that the thermistor reads temp correctly.   Testing the evap thermistor was similar - the temp displayed in the diagnostic seems true to the temp measured manually when running the diagnostic.  I have 2 thermistors on order, but it doesn't feel like the whole problem.   Should the temp displayed match what the FF cabinet thermistor is measuring or is it averaging something?  It does match up after I reset the fridge or after exiting diagnostics.

Once in a while in diagnostics the display flashes "1 10" but I'm not sure what to do with it.  

I'm still very suspect on the fact that the Turbo Cool does not engage anything (and it used to,  ago).  It should call for cooling, as should a  temp reading over 34, what the fridge is set to today.   Is there a test to kick the compressor on?         

 Thank you,

kkrep

[16345Ed]

In my opinion you should use your meter to test thermistors. I know your theory but I need to see the part is in spec. Also it can be ok or close at one temp and off at another temperature. 

[kkrep]

OK.  Simple question: I have to cut them out to fully test them right?  I was sort of avoiding that. 

Thanks for sticking with me here.

[vee8power]

4 minutes ago, kkrep said:

I have to cut them out to fully test them right?

No, check them from the board.