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Error code reference

LG Refrigerator Error Code FS E

Freezer sensor error

LG codesLG refrigerator codes

Freezer sensor error – the freezer temperature sensor has a short, open, or out-of-range resistance reading.

First step from the service manual

Check for loose connection at CON7 on the Main PCB.

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

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What FS E means on a LG refrigerator

The FS E error code on an LG refrigerator indicates a freezer temperature sensor fault. The freezer sensor, also called a thermistor, continuously monitors the temperature inside the freezer compartment and sends resistance-based readings to the Main PCB. When the control board detects that the sensor's resistance value is outside the expected operating range, or reads an open or short circuit condition in the sensor circuit, it triggers the FS E code and may reduce or disable cooling operation in the freezer section.

The sensor circuit runs from the thermistor through a wiring harness to the Main PCB, specifically to connector CON7. A short circuit occurs when the sensor's resistance drops abnormally low, while an open circuit means the signal is completely lost, often due to a broken wire or disconnected plug. An out-of-range reading can also occur when the thermistor itself has drifted outside acceptable resistance values due to age or physical damage. The first diagnostic step is to inspect CON7 on the Main PCB for a loose, corroded, or improperly seated connector, as wiring issues at this point are a frequent cause of sensor faults.

If the connector at CON7 is secure and shows no visible damage, the next focus should be the wiring harness running to the freezer sensor and the sensor itself. Resistance testing the thermistor directly can confirm whether the component has failed. A damaged wire insulation, pinched harness, or moisture intrusion near the sensor can also produce short or open circuit readings without the sensor itself being defective.

Source: manufacturer service documentation.

Common causes of FS E

  1. 01

    Loose or disconnected connector at CON7

    Wiring / connection

    The wiring harness plug at CON7 on the Main PCB can work loose over time due to vibration, causing an intermittent or complete loss of signal from the freezer sensor. Inspect and firmly reseat this connector as the first diagnostic step.

  2. 02

    Failed freezer temperature sensor (thermistor)

    Part replacement

    The thermistor itself can fail due to age or physical damage, producing a resistance reading that is shorted, open, or out of the acceptable range. Testing the sensor's resistance with a multimeter and comparing it against the specified range will confirm this failure.

  3. 03

    Damaged or pinched wiring harness

    Part replacement

    The wire harness connecting the freezer sensor to the Main PCB can become pinched, cut, or damaged by ice buildup, causing a short or open circuit condition. Visually inspect the harness along its full length for any signs of wear, crushing, or insulation damage.

  4. 04

    Corrosion or moisture at the connector

    Wiring / connection

    Moisture intrusion at the CON7 connector or at the sensor connector in the freezer compartment can cause corrosion that disrupts the signal. Look for discoloration, oxidation, or residue on the connector pins and terminals.

  5. 05

    Faulty Main PCB

    Part replacement

    If the sensor and all wiring test within normal parameters, the Main PCB may have a defect that prevents it from correctly reading the sensor signal. This is the least common cause and should only be considered after the sensor and harness have been ruled out.

See the test procedure for each cause

Frequently asked questions about FS E

What does FS E mean on a LG refrigerator?
FS E is a freezer sensor error code indicating that the Main PCB has detected a short circuit, open circuit, or out-of-range resistance reading from the freezer temperature thermistor. The control board uses this sensor to monitor freezer temperatures and regulate the cooling cycle. When the signal falls outside acceptable parameters, the code is triggered and freezer performance may be affected. The first place to check is the wiring connector at CON7 on the Main PCB.
Can I fix the FS E error on my LG refrigerator myself?
Some causes of the FS E code are DIY-friendly, such as reseating a loose connector at CON7 or inspecting the wiring harness for visible damage. If the issue is a failed thermistor, a knowledgeable DIYer comfortable with multimeter testing and basic appliance disassembly can replace the sensor. However, if the Main PCB is at fault, repair becomes more complex and a qualified technician is recommended.
Is it safe to keep using my refrigerator when FS E is displayed?
It is not advisable to continue using the freezer normally when the FS E code is active. Without an accurate temperature reading, the control board cannot properly regulate the freezer cooling cycle, which means food may not be kept at a safe temperature. You should check your freezer contents and address the error promptly to avoid food spoilage.
How much does it cost to repair an LG refrigerator FS E error?
Repair costs vary depending on the root cause. If only a connector needs to be reseated, there may be no parts cost at all, though a service call can run anywhere from $75 to $150. A replacement freezer thermistor typically costs between $15 and $50 for the part itself. If the Main PCB needs to be replaced, parts and labor combined can range from $200 to $500 or more depending on the model.
Will resetting my LG refrigerator clear the FS E error code?
A reset, such as unplugging the refrigerator for a few minutes, may temporarily clear the FS E code, but it will return if the underlying problem has not been fixed. If the sensor, wiring, or connector is genuinely faulty, the code will reappear once the control board resumes monitoring the sensor circuit. A reset is useful for confirming whether the fault is intermittent, but it is not a substitute for proper diagnosis and repair.

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