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Error code reference

LG Refrigerator Error Code R-sensor open/short

Refrigerator room temperature sensor has an open or short circuit fault, detected when sensor reading is…

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Refrigerator room temperature sensor has an open or short circuit fault, detected when sensor reading is below -50°C or above +50°C.

First step from the service manual

Check R-sensor resistance and wiring; replace sensor if faulty.

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

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  • Step-by-step tests with expected resistance, voltage, and continuity values
  • Wiring diagram references and connector pinouts from the OEM service manual
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What R-sensor open/short means on a LG refrigerator

The R-sensor open/short error on an LG refrigerator indicates a fault in the refrigerator compartment temperature sensor circuit. This sensor is a negative temperature coefficient (NTC) thermistor responsible for monitoring the temperature inside the fresh food section and feeding that data to the main control board. The control board uses this reading to regulate compressor cycles and fan operation. When the sensor output falls below -50°C or rises above +50°C, the board interprets this as an impossible reading caused by a broken circuit (open) or a short to ground or another wire (short), and triggers the fault code.

An open circuit fault typically means the sensor itself has failed internally, or the wiring harness connecting it to the control board has a break or disconnected terminal. A short circuit fault occurs when two conductors in the sensor circuit make unintended contact, pulling the resistance reading outside the valid range. Both conditions prevent the control board from making accurate temperature-based decisions, which can lead to erratic cooling, compressor over-run, or a complete shutdown of normal refrigeration cycles.

Diagnosing this fault begins with checking the resistance of the R-sensor directly at the sensor terminals. A healthy NTC thermistor will show a predictable resistance value at room temperature, typically in the range of several kilohms. A reading of zero ohms indicates a short, while an infinite or open resistance reading confirms an open circuit. The wiring harness, connector pins, and sensor mounting location should all be inspected before replacing any components.

Source: manufacturer service documentation.

Common causes of R-sensor open/short

  1. 01

    Failed R-sensor thermistor

    Part replacement

    The thermistor itself has burned out or broken internally, producing a resistance reading outside the valid range. Measuring zero ohms (short) or infinite resistance (open) directly at the sensor terminals confirms this failure.

  2. 02

    Damaged wiring harness

    Wiring / connection

    The wire connecting the sensor to the main control board may have a break, pinch, or frayed section causing an open or short circuit. Inspect the full length of the harness for visible damage, kinks, or contact with sharp edges.

  3. 03

    Loose or corroded connector

    Wiring / connection

    The connector between the sensor wiring and the control board can loosen over time or develop corrosion at the pins, disrupting the circuit. Reseating or cleaning the connector may restore proper operation without part replacement.

  4. 04

    Moisture or ice intrusion at sensor

    Wiring / connection

    Water infiltration or ice buildup around the sensor housing can cause a short circuit or degrade sensor contacts. This is more common if a door seal has been failing and allowing humid air into the compartment.

  5. 05

    Faulty main control board

    Part replacement

    If the sensor and all wiring test within normal ranges, the control board's sensor input circuit may have failed, causing it to misread a valid signal as an open or short. This is the least common cause and should be diagnosed last.

See the test procedure for each cause

Frequently asked questions about R-sensor open/short

What does R-sensor open/short mean on a LG refrigerator?
This error code means the refrigerator compartment temperature sensor is reporting a circuit fault, either an open (broken) circuit or a short circuit. The control board detects this when the sensor reading falls below -50°C or exceeds +50°C, which are impossible real-world temperatures. The fault prevents the refrigerator from accurately monitoring and regulating its internal temperature. The sensor itself or its associated wiring are the most likely sources of the problem.
Can I fix the R-sensor error myself?
A knowledgeable DIYer can perform basic diagnostics by inspecting the sensor wiring harness for visible damage and reseating the connector at the control board. Testing the sensor resistance with a multimeter will confirm whether the thermistor itself has failed. If the sensor is faulty, replacing it is a straightforward repair, but accessing the sensor location may require removing interior panels.
Is it safe to keep using my refrigerator while this error is active?
It is not advisable to rely on the refrigerator to maintain safe food temperatures while this error is active. Without a functioning temperature sensor, the control board cannot properly regulate cooling cycles, which may result in the compartment running too warm or too cold. Perishable food should be moved to another refrigerator until the fault is resolved.
How much does it cost to fix an R-sensor fault on an LG refrigerator?
If only the thermistor sensor needs replacement, parts typically cost in the range of $15 to $50 depending on the specific model. Professional labor to diagnose and replace the sensor generally adds $80 to $200. If the wiring harness or main control board is also involved, total repair costs can be higher, potentially ranging from $150 to $400 or more.
Will resetting my LG refrigerator clear the R-sensor error code?
A power reset by unplugging the refrigerator for a few minutes may temporarily clear the error code display, but the code will return if the underlying fault in the sensor or wiring has not been corrected. Resetting the unit does not repair a failed thermistor or a broken wire. A proper repair addressing the root cause is required to permanently resolve the fault.

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