LG Refrigerator Error Code RT sensor failure (FRZ+REF temp off)

The RT sensor failure code on an LG refrigerator indicates that the room temperature (ambient) sensor has experienced either an open circuit (cut wire) or a short circuit condition. The RT sensor monitors the ambient temperature surrounding the refrigerator, which the control board uses to adjust compressor and fan operation for efficient cooling. When this sensor fails or loses electrical continuity, the control board cannot read a valid signal and triggers the fault condition. The visual indicator for this fault is distinctive: all display LEDs illuminate simultaneously while both the freezer temperature display and the refrigerator temperature display go blank.

The RT sensor circuit runs wiring from the sensor element to the main control board. A cut or damaged wire breaks the circuit entirely, resulting in an open condition with no signal reaching the board. A shorted wire, where insulation breaks down and conductors contact each other or ground, sends an invalid voltage reading that the board recognizes as out of range. Either condition registers as sensor failure and disables the temperature readouts on the display panel.

Because the first diagnostic step targets the connecting wires at the RT sensor, technicians should inspect the wiring harness running to the sensor for visible damage, pinching, corrosion at connectors, or breaks. The sensor itself may also have failed internally. Resolving this fault typically requires restoring proper circuit continuity either by repairing the wiring, reseating connectors, or replacing the sensor if the wiring checks out intact.