Freezer sensor error displayed as “Er FS” and freezer temperature reading is inaccurate or dashes appear.

Safety first: Unplug the refrigerator before removing panels or handling wiring. Use insulated tools and avoid touching live circuits.

Step-by-step:

• Power reset: Unplug the refrigerator for 5 minutes, then plug back in. If Er FS returns after a few minutes, continue.
• Access the freezer sensor: Remove freezer shelves and the rear interior panel (usually held by Phillips screws). The thermistor is a small plastic-encased sensor clipped to the evaporator or wall with two wires.
• Inspect wiring: Check the thermistor wires for cuts, pinches, or ice damage. Ensure the connector is fully seated and not corroded.
• Test the thermistor: Disconnect the thermistor and measure resistance with a multimeter. At about 32°F (0°C) most LG thermistors read ~30–35 kΩ. If reading is open (OL), 0 Ω, or far out of spec, replace the sensor.
• Check harness to PCB: At the main control board (rear of unit behind a metal or plastic cover), verify continuity from the thermistor connector to the board. Repair any broken wires.
• Replace parts as needed: If wiring and thermistor test good but the error persists, the main PCB may be defective and require replacement.

When to stop: If you are not comfortable testing live circuits or removing interior panels, contact an LG-authorized technician.