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Error code reference

LG Refrigerator Error Code C/R-SEN

C/R (center-refrigerator) sensor failure detected by self-diagnosis.

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C/R (center-refrigerator) sensor failure detected by self-diagnosis.

First step from the service manual

Check resistance at CN30 No.12 ↔ No.14; 0Ω indicates short failure, ∞Ω indicates open failure.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What C/R-SEN means on a LG refrigerator

The C/R-SEN error code on an LG refrigerator indicates a failure detected in the center-refrigerator temperature sensor, also called the C/R sensor. This sensor is a thermistor that continuously monitors the internal temperature of the refrigerator compartment and reports that data to the main control board. When the self-diagnosis routine detects a resistance reading outside the acceptable range at connector CN30, specifically between pins No.12 and No.14, it flags this fault code to alert the technician that the sensor circuit has either shorted or opened.

The two distinct failure modes are identified by resistance measurement at CN30. A reading of 0 ohms between pins No.12 and No.14 indicates a short circuit, meaning the sensor or its wiring harness has an unintended direct connection causing no resistance. A reading of infinite ohms (open circuit) means the circuit is broken entirely, which can result from a failed thermistor, a broken wire, or a disconnected or corroded connector. Both conditions prevent the control board from receiving valid temperature data from the center refrigerator zone.

When this sensor fails, the refrigerator loses the ability to accurately regulate temperature in the affected compartment. This can cause the compressor and fans to run erratically or continuously, resulting in temperature instability. Common root causes include thermistor degradation over time, physical damage to the sensor wiring harness, moisture intrusion into the connector, or a faulty sensor that has drifted out of spec. Accurate diagnosis requires a multimeter check at CN30 pins No.12 and No.14 before replacing any components.

Source: manufacturer service documentation.

Common causes of C/R-SEN

  1. 01

    Failed C/R Thermistor

    Part replacement

    The thermistor itself has degraded or burned out, producing either a short or open circuit. Resistance measured at CN30 pins No.12 and No.14 will read 0 ohms or infinity, confirming the sensor needs replacement.

  2. 02

    Broken or Damaged Wiring Harness

    Part replacement

    Physical damage, pinching, or wear on the wiring between the sensor and connector CN30 can cause an open or short circuit. Visually inspect the harness run for cuts, kinks, or contact with sharp metal edges.

  3. 03

    Loose, Corroded, or Disconnected Connector at CN30

    Wiring / connection

    A poor connection at CN30 can mimic an open circuit fault. Check that the connector is fully seated and inspect the pins for corrosion or moisture damage before replacing the sensor.

  4. 04

    Moisture or Ice Buildup on Sensor

    Wiring / connection

    Ice accumulation or condensation around the sensor housing can temporarily affect its resistance readings. Defrosting the compartment fully and re-testing at CN30 can help rule this out as the root cause.

  5. 05

    Faulty Main Control Board

    Part replacement

    If the thermistor and wiring both test correctly at CN30 but the error persists, the control board circuit that reads the sensor signal may be defective. This is the least common cause and should be diagnosed last.

See the test procedure for each cause

Frequently asked questions about C/R-SEN

What does C/R-SEN mean on a LG refrigerator?
C/R-SEN indicates that LG's self-diagnosis system has detected a failure in the center-refrigerator temperature sensor circuit. The control board checks resistance at connector CN30 between pins No.12 and No.14. A reading of 0 ohms points to a short circuit, while an infinite resistance reading points to an open circuit. Both conditions mean the board cannot receive valid temperature data from that sensor.
Can I fix the C/R-SEN error myself?
A knowledgeable DIYer can diagnose this fault by using a multimeter to check resistance at connector CN30 between pins No.12 and No.14. If the connector is simply loose or corroded, reseating or cleaning it may resolve the issue without parts. If the thermistor or wiring harness is confirmed faulty, replacing the sensor is a moderate repair that requires identifying the correct replacement part for your specific LG model.
Is it safe to keep using my refrigerator when C/R-SEN is displayed?
Continuing to use the refrigerator with an active C/R-SEN fault is risky from a food safety standpoint. Without a functioning center-refrigerator sensor, the control board cannot accurately regulate the compartment temperature, which may cause temperatures to rise above safe levels without any visible indication. It is best to address the fault promptly and use a separate thermometer to monitor the compartment in the meantime.
How much does it cost to repair a C/R-SEN error on an LG refrigerator?
If only the thermistor needs replacement, parts typically cost in the range of $15 to $50 depending on the model, and a DIY repair requires minimal tools. If professional service is needed, a typical repair visit including labor and parts can range from $100 to $250. Wiring harness repairs or control board replacement will push costs toward the higher end of that range.
Will resetting my LG refrigerator clear the C/R-SEN error code?
A power reset may temporarily clear the displayed error code, but the fault will return as soon as the control board completes its self-diagnosis cycle if the underlying problem has not been fixed. Resetting the unit does not repair the sensor, wiring, or connector. A proper resistance check at CN30 pins No.12 and No.14 is required to identify and resolve the root cause before the code will stay cleared.

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