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Error code reference

LG Refrigerator Error Code R-SEN

Refrigerator sensor failure detected by self-diagnosis.

LG codesLG refrigerator codes

Refrigerator sensor failure detected by self-diagnosis.

First step from the service manual

Check resistance at CN30 No.10 ↔ 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 R-SEN means on a LG refrigerator

The R-SEN error code on an LG refrigerator indicates that the self-diagnosis system has detected a failure in the refrigerator compartment temperature sensor. This sensor, also called a thermistor, continuously monitors the internal temperature of the refrigerator section and feeds that data to the main control board. When the board receives a signal that falls outside the expected parameters, it logs the R-SEN fault to alert the technician that the sensor circuit has either shorted or opened.

Diagnosis begins at connector CN30 on the main control board. Measuring resistance between pin No.10 and pin No.14 on that connector will reveal the nature of the failure. A reading of 0 ohms indicates a short circuit, meaning the sensor wires or the sensor itself have failed in a way that collapses resistance entirely. A reading of infinite ohms (open circuit) means the circuit has been completely broken, either through a wire break, a corroded or loose connector, or a failed thermistor element. A functioning sensor should read somewhere between those two extremes, with resistance that varies predictably as temperature changes.

Common root causes include a physically damaged thermistor, corroded wiring harness connections near the sensor, or a broken wire in the harness running from the sensor to the control board. In rarer cases, the main control board itself may have a damaged input circuit at the CN30 connector, though the sensor and wiring harness should be ruled out first before condemning the board.

Source: manufacturer service documentation.

Common causes of R-SEN

  1. 01

    Failed refrigerator thermistor

    Part replacement

    The thermistor itself has failed internally, producing either a short (0 ohms) or open circuit (infinite ohms) when measured at CN30 pins No.10 and No.14. This is the most common cause and is confirmed by the resistance test at the connector.

  2. 02

    Corroded or loose connector at CN30

    Wiring / connection

    Moisture or age can corrode the CN30 connector pins, causing an intermittent or complete loss of signal from the sensor. Inspect the connector for oxidation, bent pins, or a loose fit before replacing the sensor.

  3. 03

    Broken or damaged wiring harness

    Part replacement

    The wire harness running from the refrigerator compartment sensor to the main control board may have a break or pinch point, resulting in an open circuit reading. Visually trace the harness for signs of chafing, pinching, or breaks.

  4. 04

    Sensor harness pulled loose during service

    Wiring / connection

    If the refrigerator interior panels were recently removed for any repair, the sensor connector may have been inadvertently disconnected or stressed. Reconnecting a fully seated harness at CN30 can resolve the fault without parts.

  5. 05

    Defective main control board

    Part replacement

    If the thermistor and all wiring check out within normal resistance ranges, the input circuit on the main control board at the CN30 connection may be damaged. This is the least likely cause and should only be considered after all other components are ruled out.

See the test procedure for each cause

Frequently asked questions about R-SEN

What does R-SEN mean on a LG refrigerator?
R-SEN is an error code indicating that LG's self-diagnosis system has detected a failure in the refrigerator compartment temperature sensor. The sensor circuit has either shorted to 0 ohms or opened to infinite ohms, both of which prevent the control board from accurately reading the compartment temperature. The fault is confirmed by measuring resistance at connector CN30, between pins No.10 and No.14.
Can I fix the R-SEN error myself?
A knowledgeable DIYer can start by inspecting the CN30 connector for loose or corroded pins and reseating the harness. If that does not clear the code, a resistance test at CN30 pins No.10 and No.14 will determine whether the sensor has shorted or opened. Replacing the thermistor is a moderate DIY repair, but if the main control board is found to be at fault, professional service is recommended.
Is it safe to keep using my refrigerator while R-SEN is displayed?
Operating the refrigerator with an active R-SEN code carries a risk of inadequate cooling, because the control board cannot accurately regulate compartment temperature without a working sensor. Food safety may be compromised if temperatures rise above safe levels. It is best to address the fault promptly and monitor internal temperatures closely in the meantime.
How much does it cost to repair the R-SEN error on an LG refrigerator?
If only the thermistor needs replacement, parts typically range from $15 to $50, with professional labor adding $80 to $150 depending on location. If the main control board is at fault, parts alone can range from $100 to $300 or more. Getting a diagnostic estimate from a technician before committing to parts is advisable.
Will resetting my LG refrigerator clear the R-SEN error code?
A power reset may temporarily clear the R-SEN code from the display, but if the underlying sensor, wiring, or connector fault still exists, the code will return shortly after the refrigerator resumes operation. A reset is not a repair. The resistance at CN30 pins No.10 and No.14 must fall within a normal range before the fault will stay cleared.

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