GE model gfss6kkxass front display will not let me adjust temp, only displays 88

https://www.manualslib.com/products/Ge-Gfss6kkxass-And-2899074.html

Press the up or down key- once the display lights up you can adjust the temp... if the panel doesn't respond you need a new keypad

UNPLUG IT FOR 10 MINUTES, WHEN YOU PLUG IT BACK IN HOLD A SET BUTTON, LIKE 'CLOCK'

This repair is too complicated for the homeowner..
About the only this you can try is to unplug the power cord
wait 3-5 minutes and restore power. If no results I would
go to the main motherboard then to the display board..
These are R/R (Remove & Replace) parts and can be expensive
to repair..

Try removing all power for 1 minute, see if it resets.
88 on a display is a "test" display usually....all lights lit
also check if the controls are locked....top right button

Standard 10K ohm sensor appears to be compromised. Replace it.
You have one for water temp, one for air temp, and one for the solar if you have one.

This may prove helpful:

Rome Solarium 125 Service Mode:
Entering Service Mode
1. Hold the Hand button for 10 seconds until "Loc" is displayed
2. Press and hold the up arrow button until the numbers starting counting upward rapidly, stop at 50
3. Press the Hand button to enter Service Mode

Calibrating the Water Temperature
1. Enter service mode as per above instructions
2. Scroll to "tSC" (temperature sensor calibration) using up or down arrow buttons
3. Press the Hand button to calibrate the sensor, the current calibrated temperature will be displayed
4. Adjust the current displayed temperature reading to match the actual desired temperature using the up and down arrow buttons (leaving a few seconds between adjustments for sensor to use new setting)
For example, if tSC display reads 88 but the pool temperature is actually 86, press the down arrow twice
4. Once the selection is made, wait 10 seconds for the display to timeout and go back to the normal display

I had this issue after a power outage with our GE Profile Model GFSF6KKY Dispenser Model. No solution that I could find online helped me so I started trying different button combinations. Pressing Adjust Freezer and Adjust Refrigerator buttons at the same time and holding it for at least 10 seconds worked for me.

Go into the diagnostic mode on your touch display .
1) . Press any button on the display 1 time except the temp adjust buttons.
2) Press the temp up and down on both the freezer AND refrig (all 4 at the same time)
3) when 0's show , release the buttons and press any button except for the temp adjust buttons .
4) NOW , fress the temp adjust buttons until the freezer side displays 0 and the refrig side displays 7 . 0 and 7 is for the thermistors test .
5) After 0 and 7 display , press any button again except temp adjust , and this will start the thermistor check .
6) You will have 7 thermistor tests , indicated on the refrig display , starting at 1 , then 2 then .......
7) The feezer display will tell for the corresponding thermistor , indicated by the refrig display , if the thermistor p = pass , s = short , b = bad (replace board)

After determining if or which thermistor is bad , then adjust the display to 1 on freezer display and 6 on the refrig display . This ends the testing procedure and resets the refrig back to normal .

Ok, I had the same problem with this fridge. It is in "demo" mode. You have to push in and hold the Energy Save and Adjust Freezer buttons at the same time. Hold these in until the display starts flashing. You should hear the compressor kick on. I did this, and it was fixed and started cooling in a matter of seconds.