LG Refrigerator Error Code C/F-SEN

C/F-SEN indicates that the LG refrigerator's self-diagnostic system has detected a failure in the center-freezer temperature sensor. The control board monitors the sensor circuit at connector CN30 and logs this code when it detects either a short circuit (0 ohms) or an open circuit (infinite resistance) between pins No.5 and No.7. Without a valid temperature reading, the refrigerator cannot properly regulate freezer cooling. The fault requires testing the sensor, wiring harness, and connector to determine the exact cause.

A power reset may temporarily clear the code from the display, but the error will return if the underlying sensor circuit fault has not been corrected. Because the refrigerator's self-diagnostic system actively monitors the sensor signal during operation, any short or open condition will trigger the code again shortly after restart. A reset is useful for confirming whether a fault is persistent, but it is not a repair.

If only the center-freezer thermistor needs replacement, parts typically range from $15 to $50 depending on the specific model, with labor adding $80 to $150 if a technician performs the work. If the wiring harness requires replacement, parts and labor combined can range from $100 to $250. Control board replacement, which is the least likely repair, can push total costs to $200 to $400 or more. Getting a diagnostic assessment before committing to parts is recommended.

Start by locating connector CN30 on the main control board and measuring resistance between pins No.5 and No.7 using a multimeter. A reading of 0 ohms points to a short in the sensor or wiring, while an infinite reading points to an open circuit caused by a broken wire, bad connector, or failed thermistor. Check the connector for corrosion or looseness first, then inspect the wiring harness for damage. If the harness and connector are intact, replacing the center-freezer thermistor is the most likely repair.

Operating the refrigerator with an active C/F-SEN code means the control board is not receiving accurate temperature data from the center-freezer compartment. This can lead to inconsistent cooling, food safety concerns if temperatures rise above safe levels, or potential compressor issues if the system overcompensates. It is advisable to check and address the fault promptly rather than continuing to rely on the unit for food storage.