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Error code reference

LG Refrigerator Error Code DEFROSTING SENSOR OF CF COMPARTMENT

CF compartment defrosting sensor error

LG codesLG refrigerator codes

CF compartment defrosting sensor error: electric wire cut, short-circuit, contact failure, or sensor housing missing; displayed when sensor temperature is not lower than 122°F nor higher than -58°F.

First step from the service manual

Check the voltage between Main PCB CN 30 No. 6 ↔ 7 to see if it is between 4.5V and 1.0V.

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

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What DEFROSTING SENSOR OF CF COMPARTMENT means on a LG refrigerator

The CF compartment defrosting sensor error on LG refrigerators indicates a fault detected in the defrost sensor located in the CF (convertible freezer) compartment. This sensor monitors temperature during the defrost cycle, and the control system flags an error whenever the sensor reports a temperature outside the valid operating range: not lower than -58°F and not higher than 122°F. Any reading outside this window signals that the sensor circuit is not functioning correctly, which prevents the refrigerator from accurately managing the defrost cycle in that compartment.

The error can stem from four primary fault conditions: a broken or cut wire in the sensor circuit, a short circuit within the wiring harness or sensor itself, a loose or corroded connector causing contact failure, or a physically missing or improperly seated sensor housing. Because the defrost cycle depends on accurate temperature feedback to know when to start and stop heating, a faulty sensor can lead to frost buildup, poor cooling performance, or continuous defrost operation in the CF compartment.

The recommended first diagnostic step is to measure the voltage between pins 6 and 7 on connector CN 30 at the Main PCB. A healthy sensor circuit will read between 1.0V and 4.5V under normal operating conditions. A reading outside this range, or no voltage at all, confirms a wiring or sensor fault that requires further inspection of the harness, connector integrity, and the sensor element itself.

Source: manufacturer service documentation.

Common causes of DEFROSTING SENSOR OF CF COMPARTMENT

  1. 01

    Faulty or failed defrost sensor

    Part replacement

    The sensor itself may have failed internally, causing it to report a temperature outside the valid range of -58°F to 122°F. Confirm by checking the voltage at Main PCB CN 30 pins 6 and 7; a reading outside 1.0V to 4.5V points to the sensor as the likely culprit.

  2. 02

    Broken or cut sensor wire

    Part replacement

    A break in the wiring between the sensor and the Main PCB will cause an open circuit and trigger this error. Visually inspect the harness running to the CF compartment sensor for any pinched, frayed, or severed wires.

  3. 03

    Loose or corroded connector contact

    Wiring / connection

    Intermittent contact at the sensor connector or at CN 30 on the Main PCB can produce a false fault signal. Unplug and reseat all connectors in the sensor circuit and check for corrosion or bent terminals.

  4. 04

    Short circuit in the sensor wiring harness

    Part replacement

    A short within the harness can pull the voltage reading out of the expected 1.0V to 4.5V window at CN 30. Inspect the wiring for any areas where insulation has worn through and bare wires may be contacting each other or a metal surface.

  5. 05

    Missing or improperly seated sensor housing

    Part replacement

    If the sensor housing is not installed correctly or is absent entirely, the sensor cannot read the compartment temperature accurately. Check that the sensor is physically present in its mounting location and fully seated in the housing.

See the test procedure for each cause

Frequently asked questions about DEFROSTING SENSOR OF CF COMPARTMENT

What does DEFROSTING SENSOR OF CF COMPARTMENT mean on a LG refrigerator?
This error indicates that the defrost sensor in the CF (convertible freezer) compartment has reported a temperature outside the valid range of -58°F to 122°F. The fault can be caused by a cut wire, short circuit, loose connector, or a missing sensor housing. The refrigerator displays this code because it can no longer reliably control the defrost cycle in that compartment. Diagnosis starts by checking the voltage at Main PCB connector CN 30 pins 6 and 7, which should read between 1.0V and 4.5V.
Can I fix the CF compartment defrost sensor error myself?
Some causes, such as a loose connector, can be resolved without replacing any parts by unplugging and reseating the connector at the sensor and at the Main PCB. However, a broken wire, shorted harness, or failed sensor will require replacement parts and basic skills with a multimeter and appliance disassembly. If you are not comfortable working with wiring or internal refrigerator components, a qualified technician should perform the repair.
Is it safe to keep using my refrigerator while this error is displayed?
Continued use is risky because the refrigerator cannot properly manage the defrost cycle in the CF compartment without a working sensor. This can lead to excessive frost buildup, reduced cooling efficiency, or in some cases continuous defrost heating. It is best to address the fault promptly to avoid food spoilage or further component damage.
How much does it cost to repair the CF compartment defrosting sensor error on an LG refrigerator?
Repair costs vary depending on the root cause. A replacement defrost sensor typically costs between $15 and $50 for the part alone. If the wiring harness needs repair or replacement, parts and labor combined can range from $100 to $250 or more. A service call from a technician for diagnosis and repair generally adds $75 to $150 in labor costs depending on your location.
Will resetting the refrigerator clear the CF compartment defrost sensor error?
A power reset may temporarily clear the error code from the display, but it will return as soon as the control system re-evaluates the sensor circuit. Because the fault is caused by a physical problem such as a broken wire, failed sensor, or bad connection, the underlying issue must be repaired before the error will stay cleared. Resetting is useful only as a first step to confirm whether the fault is intermittent or persistent.

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