Assuming nothing has failed, press and hold the Temperature button for 3 seconds, then options will appear to raise and lower the refrigerator and freezer temperature. Press the temperature button again after you have adjusted the temperature to 38 degrees or so in the refrigerator.
Now if that doesn't fix the issue something has failed. If the refrigerator section is too cold, there are only 2 options. Either your thermistor sensor is off, or the damper isn't closing and it's allowing air into the refrigerator when it shouldn't. You can't test the damper but you can test the thermistor. Below is a link to both parts.
CLICK HERE for damper
CLICK HERE for thermistor
The thermistor is mounted to the right side wall of the refrigerator toward the back behind a 2" x 1" plastic cover. The problem with testing it is that it's hard wired in so you would have to cut the 2 wires and test resistance through the sensor. It should read about 10k ohms at room temperature and if not, then replace it. If it does read 10k ohms then replace the damper assembly.
Now if you don't have a multimeter to test, just replace the damper assembly at the top of the refrigerator in the back left corner where the air comes into the refrigerator from the freezer first since you can always return it and it's all plug and play.
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