Error code
R4
Meaning
Fresh food compartment temperature sensor is malfunctioning
Moderate
What to do
Why this happens
Possible causes include separation in sensor housing, contact errors at connectors, disconnection of sensor wires, short circuits within sensor lines, or temperature readings outside the range of -58°F to 149°F.
How to fix it
Replace the fresh food compartment temperature sensor
SourceSamsung service manual