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Error code reference

LG Refrigerator Error Code r

Refrigerator sensor failure

LG codesLG refrigerator codes

Refrigerator sensor failure - short circuit or open wires in the refrigerator sensor.

First step from the service manual

Check for loose connection at CON4, then measure resistance between White and White wires on CON4.

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

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What r means on a LG refrigerator

The error code "r" on an LG refrigerator indicates a failure in the refrigerator compartment temperature sensor. This sensor is a thermistor, a resistive component whose resistance value changes predictably with temperature. The control board uses this resistance reading to monitor compartment temperature and regulate the cooling cycle. When the board detects either a short circuit (abnormally low resistance) or an open circuit (infinite or no resistance), it flags the "r" error and loses the ability to accurately control refrigerator compartment cooling.

The primary diagnostic starting point is the CON4 connector on the wiring harness. A loose or corroded connection at CON4 can mimic both a short and an open circuit condition, making connector inspection the first and most important step. After confirming the connector is fully seated and free of corrosion or damage, a technician should measure the resistance between the two White wires on CON4. The measured value should correspond to the expected thermistor resistance curve for the compartment temperature at the time of testing. A reading of zero or near-zero ohms indicates a short circuit, while a reading of infinite ohms (open line) confirms a broken wire or failed thermistor.

Failure can originate at three points: the thermistor itself, the wiring harness between the sensor and CON4, or the connector. Physical damage to the wiring, such as pinching during a prior service call or freezing and cracking in a cold environment, can cause open or intermittent faults. The thermistor element can also fail internally over time. Resolving this code requires isolating which component in the circuit is out of specification and replacing it accordingly.

Source: manufacturer service documentation.

Common causes of r

  1. 01

    Loose or corroded connection at CON4

    Wiring / connection

    A partially seated or corroded connector at CON4 is the most frequent cause, as it interrupts the circuit without any component actually failing. Inspect CON4 for secure seating, bent pins, and corrosion before proceeding to other diagnostics.

  2. 02

    Failed refrigerator compartment thermistor

    Part replacement

    The thermistor itself can fail internally, resulting in either a short circuit (near-zero resistance) or an open circuit (no resistance reading) between the White wires at CON4. Resistance measurement will confirm whether the sensor is out of specification.

  3. 03

    Damaged wiring harness

    Part replacement

    The wiring between the thermistor and CON4 can be pinched, cut, or cracked, particularly if the harness was disturbed during a prior repair or if moisture caused the insulation to degrade. Visually inspect the full length of the harness for any visible damage.

  4. 04

    Open circuit caused by wire break inside insulation

    Part replacement

    A wire can break internally without visible external damage, especially at flex points near connectors. An open resistance reading between the White wires at CON4, combined with a visually intact harness, suggests an internal wire break requiring harness replacement.

  5. 05

    Short circuit from moisture or ice buildup

    Wiring / connection

    In some cases, moisture intrusion or ice accumulation near the sensor or harness can cause a short circuit condition. If the compartment has experienced excessive frost buildup, inspect the sensor mounting area for signs of moisture damage after defrosting.

See the test procedure for each cause

Frequently asked questions about r

What does r mean on a LG refrigerator?
The "r" error code on an LG refrigerator indicates a refrigerator compartment sensor failure, specifically either a short circuit or an open circuit in the temperature sensor circuit. The control board cannot get a valid resistance reading from the thermistor and triggers this code as a result. This fault prevents accurate temperature monitoring and can affect the refrigerator's ability to maintain proper cooling. Diagnosis starts at the CON4 connector and involves measuring resistance between the two White wires.
Can I fix the r error code on my LG refrigerator myself?
Checking and reseating the CON4 connector is a straightforward step that a careful DIYer can perform after unplugging the refrigerator. If the connector is secure, diagnosing the fault further requires a multimeter to measure resistance between the White wires at CON4. If the thermistor or wiring harness is confirmed faulty, replacing those components involves working inside the refrigerator liner and may require partial disassembly, which is better suited to a technician with appliance repair experience.
Will resetting my LG refrigerator clear the r error code?
A power reset may temporarily clear the error code display, but if the underlying fault in the sensor circuit is still present, the "r" code will return once the control board runs its diagnostic checks again. A reset is not a fix and should only be used to confirm whether the fault is persistent or intermittent. The wiring and sensor resistance must be tested and corrected to resolve the code permanently.
Is it safe to keep using my LG refrigerator while the r error is showing?
Operating the refrigerator with an active "r" error code is not recommended for extended periods, because the control board cannot accurately regulate the refrigerator compartment temperature without a functioning sensor. Food safety may be compromised if the compartment temperature drifts out of a safe range. It is best to address the fault promptly and monitor food temperatures closely in the meantime.
How much does it cost to repair the r error code on an LG refrigerator?
If the fix is simply reseating a loose connector at CON4, there is no parts cost and only a service call fee if a technician is involved, typically in the range of $75 to $150 depending on your area. Replacing a faulty thermistor sensor is generally a lower-cost repair, with parts usually ranging from $15 to $50 and labor adding $100 to $200. If the wiring harness requires replacement, total costs can be higher depending on the extent of the damage and parts availability.

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