Display shows F4 and oven may not start or may shut down unexpectedly during operation.

Safety first: Turn off power at the breaker before working on the range.

• Inspect sensor and wiring: Locate the oven temperature sensor at the rear of the oven cavity. Remove it and inspect the probe and wiring for signs of melting, charring, or moisture.
• Measure resistance: With the sensor disconnected, measure resistance with a multimeter. A reading near 0 Ω indicates a shorted sensor; replace it.
• Check for wire shorts: Inspect the harness from the sensor to the control board. Look for spots where the insulation has rubbed through and is touching the metal chassis. Repair with high-temperature wire and proper connectors or replace the harness.
• Dry connectors: If there has been a spill or steam intrusion, dry the sensor connector and control board area thoroughly before reassembly.

If F4 persists after replacing the sensor and repairing wiring, the EOC may be damaged and require replacement.