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Error code reference

LG Refrigerator Error Code Er (outside sensor)

Snapping or short-circuit of outside temperature perceiving sensor

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Snapping or short-circuit of outside temperature perceiving sensor. Displayed as 'Er' on the outside temperature display part while other displays remain normal.

First step from the service manual

Check outside temperature sensor resistance.

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
  • Verified part numbers when replacement is required
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What Er (outside sensor) means on a LG refrigerator

The Er error code on an LG refrigerator's outside temperature display indicates a fault with the outside temperature sensing sensor. Specifically, the code is triggered when the control system detects either an open circuit (wire snapping or broken sensor element) or a short circuit in the sensor circuit. While this error appears on the outside temperature display portion of the unit, all other display segments and refrigerator functions continue to operate normally, which helps isolate the fault to this single sensor circuit.

The outside temperature sensor is a thermistor, a resistive component whose electrical resistance changes predictably with temperature. When the control board sends a small reference voltage through the sensor circuit and reads back an out-of-range resistance value, it interprets this as either a broken wire (extremely high resistance, open circuit) or a shorted sensor (extremely low resistance, near zero ohms). The first diagnostic step is to measure the sensor's resistance directly with a multimeter and compare it against the expected value for the ambient temperature. A reading that is infinite or near zero confirms sensor failure.

Common causes include physical damage to the sensor wiring harness, corrosion at the sensor connector, or degradation of the thermistor element itself over time. Because the sensor is located on the exterior of the unit, it can be more exposed to moisture and temperature cycling than interior components, which accelerates connector corrosion and wire insulation breakdown. Replacing the sensor and inspecting the associated wiring and connector pins are the standard corrective steps.

Source: manufacturer service documentation.

Common causes of Er (outside sensor)

  1. 01

    Failed thermistor (open circuit)

    Part replacement

    The thermistor element inside the sensor has broken down or the sensor wire has snapped, resulting in an open circuit with infinite or very high resistance. This is the most common cause and is confirmed by measuring resistance across the sensor terminals.

  2. 02

    Shorted sensor circuit

    Part replacement

    A short circuit in the sensor or its wiring causes near-zero resistance, which the control board reads as an invalid signal. Inspect the wiring harness for pinched or damaged insulation that may be causing two conductors to contact each other.

  3. 03

    Corroded or loose connector

    Wiring / connection

    The connector joining the sensor to the wiring harness can accumulate corrosion or work loose over time, creating intermittent or complete loss of electrical contact. Inspect the connector pins for green or white oxidation and ensure the connector is fully seated.

  4. 04

    Damaged wiring harness

    Part replacement

    Physical damage to the wire running from the sensor to the control board, such as chafing, rodent damage, or stress fractures from repeated door use, can interrupt the circuit. Visually trace the harness and check for breaks or worn insulation.

  5. 05

    Control board fault

    Part replacement

    In rare cases, the control board's sensor input circuit may fail, causing it to misread a properly functioning sensor as open or shorted. This should only be considered after confirming the sensor and wiring are within specification.

See the test procedure for each cause

Frequently asked questions about Er (outside sensor)

What does Er (outside sensor) mean on a LG refrigerator?
The Er code on an LG refrigerator indicates that the outside temperature sensor has either an open circuit (broken wire or failed thermistor) or a short circuit. It appears specifically on the outside temperature display while all other displays and refrigerator functions continue to work normally. The control board detected an out-of-range resistance reading from the sensor circuit and triggered the error to alert you to the fault.
Can I fix the Er outside sensor error myself?
A knowledgeable DIYer can start by checking the sensor's wiring connector for corrosion or looseness and reseating it, which costs nothing. If that does not resolve the issue, the next step is measuring the sensor's resistance with a multimeter to confirm whether the sensor itself has failed. Replacing a thermistor sensor is a straightforward repair, but you should be comfortable working with appliance wiring and sourcing the correct replacement part for your specific LG model.
Is the Er outside sensor error dangerous or will my food spoil?
This error is isolated to the outside temperature sensor and does not affect the refrigerator's cooling system or interior temperature control. Your food is not at risk as a result of this specific code. However, you should still address the fault to restore full monitoring functionality and prevent any underlying wiring issue from potentially affecting other components over time.
Will resetting my LG refrigerator clear the Er outside sensor error?
A power reset may temporarily clear the error display, but the code will return if the underlying sensor fault is still present. The control board will re-detect the open or short circuit in the sensor the next time it runs a diagnostic check. A permanent fix requires repairing or replacing the faulty sensor or wiring rather than simply resetting the unit.
How much does it cost to repair the Er outside sensor error on an LG refrigerator?
If the repair is limited to the thermistor sensor itself, parts typically range from around $15 to $50 depending on the model. If professional labor is involved, total repair costs generally fall in the range of $100 to $250 including the service call and parts. Costs can be higher if the wiring harness requires replacement or if the fault is traced to the control board.

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