Error code “F dS” or similar and freezer temperature reading is erratic; frost issues may occur.

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Failed freezer defrost thermistor, Corroded sensor connector, Damaged sensor wiring, Faulty main PCB input

Safety: Disconnect power before accessing the evaporator area.

Locate defrost sensor: Clipped to the freezer evaporator tubing, often near the top or middle of the coil.
Inspect and reseat: Check for moisture, corrosion, or loose connection. Reseat the connector.
Test sensor: Measure resistance at a known temperature and compare to LG thermistor specs. Replace if out of range.
Check harness: Verify continuity from sensor to main PCB. Repair any breaks.

Medium 3/5

Freezer Defrost Thermistor

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