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Error code reference

LG Refrigerator Error Code Outer sensor open

Ambient (outer) temperature sensor open circuit fault

LG codesLG refrigerator codes

Ambient (outer) temperature sensor open circuit fault - sensor reading suspected to be below -50°C.

First step from the service manual

Check outer 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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What Outer sensor open means on a LG refrigerator

The "Outer sensor open" error on an LG refrigerator indicates an open circuit fault in the ambient temperature sensor, also referred to as the outer sensor. This sensor is responsible for measuring the surrounding air temperature outside the refrigerator cabinet. When the control board receives a signal corresponding to a temperature reading suspected to be below -50°C, it interprets the input as an open circuit condition, meaning the electrical path through the sensor has been broken. At that extreme low reading, the thermistor is essentially reporting no valid resistance, which the board flags as a fault.

The outer (ambient) sensor is a negative temperature coefficient (NTC) thermistor. Under normal conditions, its resistance changes predictably with temperature. An open circuit occurs when the sensor itself has failed internally, or when the wiring harness connecting it to the control board has been damaged, corroded, or disconnected. A broken wire, a loose connector pin, or a corroded terminal can all interrupt the circuit and produce the same open-fault reading as a failed sensor.

Diagnosing this fault starts with a resistance check at the sensor terminals. If the sensor reads infinite resistance (open), it has failed and needs replacement. If resistance appears normal at the sensor but the fault persists, inspect the wiring harness for breaks, pinched wires, or loose connector seats between the sensor and the main control board. Connector pins should be checked for corrosion or backing out of the housing.

Source: manufacturer service documentation.

Common causes of Outer sensor open

  1. 01

    Failed ambient temperature sensor

    Part replacement

    The NTC thermistor has developed an internal open circuit, causing it to report an out-of-range signal below -50°C. Measuring infinite resistance across the sensor terminals confirms this failure.

  2. 02

    Broken or damaged wiring harness

    Wiring / connection

    A wire in the harness between the outer sensor and the control board may be pinched, cut, or broken. Visually inspect the full wire run and use a continuity tester to locate any break.

  3. 03

    Loose or corroded connector

    Wiring / connection

    The connector joining the sensor to the wiring harness can loosen over time or develop corrosion on the terminals, interrupting the circuit. Unplug and reseat the connector, and inspect pins for oxidation or backing out of the housing.

  4. 04

    Damaged connector pin

    Wiring / connection

    Individual pins inside the harness connector can bend, retract, or corrode, creating an intermittent or permanent open circuit even when the sensor and wiring are otherwise intact.

See the test procedure for each cause

Frequently asked questions about Outer sensor open

What does Outer sensor open mean on a LG refrigerator?
This error means the control board has detected an open circuit in the ambient (outer) temperature sensor. The board expects a resistance signal from the sensor corresponding to a real-world temperature, but the reading has fallen below the valid threshold of -50°C, which the board interprets as a broken or disconnected circuit. The fault can originate from the sensor itself, the wiring, or a connector in the harness.
Can I fix the Outer sensor open error myself?
Yes, if you have basic electrical diagnostic skills. Start by locating the outer sensor, disconnecting it, and measuring its resistance with a multimeter. An infinite or open reading means the sensor needs to be replaced. If the sensor checks out, trace the wiring harness for breaks or loose connectors and repair or reseat as needed.
Will resetting my LG refrigerator clear the Outer sensor open error?
A reset may temporarily clear the error code from the display, but the fault will return if the underlying problem has not been fixed. The control board will re-detect the open circuit as soon as it polls the sensor again. Clearing the code is not a repair; the sensor or wiring issue must be resolved first.
Is it safe to keep using my LG refrigerator when the Outer sensor open error is displayed?
The refrigerator may continue running in some capacity, but without a valid ambient temperature reading the control board cannot make accurate decisions about cooling cycles and compressor operation. This could result in inefficient cooling or food not being kept at safe temperatures. It is best to address the fault promptly rather than rely on the unit to perform normally.
How much does it cost to repair the Outer sensor open error on an LG refrigerator?
If only the ambient temperature sensor needs replacement, parts typically range from $15 to $50 depending on the model, making it a relatively low-cost DIY repair. If a professional technician is needed, the total cost including labor could range from $80 to $200 or more. Wiring repairs, if required, will vary based on the extent of the damage.

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