LG oven displays F4 and will not heat correctly; may overheat or shut down unexpectedly.

Safety first: Turn off power at the breaker before testing.

• Access the sensor: Remove the oven racks. Locate the sensor probe on the back wall and remove its mounting screws. Pull it forward to access the connector.
• Measure resistance: Disconnect the sensor and test with a multimeter. At room temperature, it should be ~1080–1100 Ω. A very low reading (near 0 Ω) indicates a shorted sensor.
• Inspect wiring: Follow the sensor wires to the rear of the oven and to the control board. Look for melted insulation, pinched wires, or contact with metal chassis. Repair any damaged sections and secure away from hot surfaces.
• Check connectors: Ensure connectors are dry and free of corrosion. If moisture is present (e.g., from steam cleaning), allow to dry completely before retesting.
• Replace sensor if needed: If the sensor is shorted, install a new LG oven temperature sensor and reassemble. Restore power and test a low-temperature bake.