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Error code reference

LG Refrigerator Error Code R-SENSOR ERROR

Refrigerator sensor fault

LG codesLG refrigerator codes

Refrigerator sensor fault — sensor housing slip-out, contact defect, wire cut, wire short, or sensor temperature out of range (above 122°F/+50°C or below -122°F/-50°C).

First step from the service manual

Check voltage between Main PCB CN30 pins 6↔7; it shall be within 4.5V~1.0V.

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

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What R-SENSOR ERROR means on a LG refrigerator

The R-SENSOR ERROR code on an LG refrigerator indicates a fault in the refrigerator compartment temperature sensor circuit. This sensor is a thermistor that continuously reports compartment temperature to the main PCB, allowing the control board to regulate compressor operation and maintain proper cooling. When the board detects a signal that falls outside of acceptable parameters, it logs this error and may limit or disable normal cooling functions to protect the unit.

The fault can stem from several distinct failure modes: the sensor housing slipping out of its mounting bracket, a contact defect at the connector, a cut or broken wire along the harness, a short circuit in the wiring, or an actual temperature reading that has gone out of the valid range. The valid temperature range for the sensor signal is above -122°F (-50°C) and below 122°F (50°C). Readings outside this window are interpreted by the board as a sensor failure rather than a real ambient condition.

The primary diagnostic starting point is measuring voltage at the main PCB connector CN30, between pins 6 and 7. Under normal operating conditions, this voltage will fall between 1.0V and 4.5V, varying with compartment temperature. A reading at or near 0V typically indicates a short circuit or severed wire, while a reading at or near 5V with no variation suggests an open circuit, a disconnected sensor, or a sensor that has slipped out of contact. These voltage readings help isolate whether the fault lies in the wiring harness, the connector, or the sensor itself.

Source: manufacturer service documentation.

Common causes of R-SENSOR ERROR

  1. 01

    Sensor housing slip-out or loose mounting

    Wiring / connection

    The sensor can work free from its mounting clip or bracket, causing intermittent or complete loss of signal. Inspect the sensor housing in the refrigerator compartment to confirm it is fully seated and secured.

  2. 02

    Connector contact defect at CN30

    Wiring / connection

    Corrosion, bent pins, or a partially unseated connector at CN30 pins 6 and 7 on the main PCB can cause a faulty voltage reading. Check the connector for secure engagement and clean contact surfaces.

  3. 03

    Cut or broken wire in the sensor harness

    Part replacement

    Physical damage to the wiring harness between the sensor and the main PCB can create an open circuit, typically causing the voltage at CN30 pins 6 and 7 to read near 5V with no variation. Visually trace the harness and use a continuity check to locate the break.

  4. 04

    Short circuit in the sensor wiring

    Part replacement

    A wire short, often caused by chafing against a metal edge or pinching during reassembly, will typically pull the voltage at CN30 pins 6 and 7 to near 0V. Inspect the harness routing for any damaged insulation.

  5. 05

    Failed refrigerator compartment thermistor

    Part replacement

    The sensor itself can fail internally, producing a resistance value that translates to a temperature reading below -122°F (-50°C) or above 122°F (50°C). If wiring and connectors check out, replacing the thermistor is the next step.

See the test procedure for each cause

Frequently asked questions about R-SENSOR ERROR

What does R-SENSOR ERROR mean on a LG refrigerator?
R-SENSOR ERROR indicates a fault in the refrigerator compartment temperature sensor circuit. The main PCB has detected that the sensor signal is outside the valid range, which can result from a loose sensor, a wiring issue such as a cut or short, a bad connector contact, or a failed thermistor. The valid sensor operating range is between -122°F (-50°C) and 122°F (50°C). When the signal falls outside this range, the board logs the error and cooling performance may be affected.
How do I fix the R-SENSOR ERROR on my LG refrigerator?
Start by checking the voltage at main PCB connector CN30, pins 6 and 7. The reading should be between 1.0V and 4.5V under normal conditions. If the voltage is at 0V, check for a short or severed wire; if it is pinned near 5V with no change, look for an open circuit or disconnected sensor. Also confirm the sensor housing is fully seated in its bracket and that the connector is free of corrosion or damaged pins. If the wiring and connections are intact but the voltage is still wrong, the thermistor itself likely needs to be replaced.
Will resetting my LG refrigerator clear the R-SENSOR ERROR?
A reset may temporarily clear the error display, but the code will return if the underlying fault has not been corrected. The error is triggered by a hardware condition, specifically a sensor signal that is out of range or absent entirely. Addressing the root cause, whether it is a loose sensor, damaged wiring, or a failed thermistor, is required to permanently resolve the fault.
Is it safe to use my LG refrigerator while the R-SENSOR ERROR is showing?
Using the refrigerator while this error is active carries a risk of inadequate cooling because the control board cannot accurately regulate compartment temperature without a valid sensor signal. Food safety may be compromised if the compartment temperature rises above safe levels without triggering a proper response from the cooling system. It is recommended to check and repair the fault promptly rather than continuing to run the unit in this condition.
How much does it cost to repair an R-SENSOR ERROR on an LG refrigerator?
Repair costs vary depending on the specific cause. If the fix is simply reseating the sensor or reconnecting a loose connector, there may be little to no parts cost, with only a service call fee if a technician is involved, typically ranging from $75 to $150. Replacing the thermistor sensor itself usually involves parts costs in the range of $20 to $60, plus labor if professionally serviced. Wiring harness repairs or main PCB replacement, if the board is damaged, can push total costs higher, generally between $150 and $400 or more depending on the extent of the repair.

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