Safety first: Disconnect power to the range before accessing the rear or internal wiring.

Visual inspection: Remove the rear access panel. Locate the oven temperature sensor wiring from the back of the oven cavity to the control board. Look for melted or pinched insulation where the harness passes near hot surfaces.
Check sensor resistance: Disconnect the sensor at the connector and measure resistance with a multimeter. A very low reading (near 0 Ω) indicates a shorted sensor that must be replaced.
Inspect for shorts to chassis: With the sensor disconnected, check each sensor lead to chassis ground. Any continuity indicates a shorted wire or damaged insulation that must be repaired.
Replace components: Replace the oven temperature sensor if shorted. If wiring is damaged, repair with high-temperature rated wire and proper connectors, or replace the harness if available.

When to call a technician: If the short appears to be inside the oven cavity wall or main harness, professional service is recommended.

Display shows F4, oven may not start or may shut off unexpectedly.

Possible Causes