Oven displays F4 and may not heat correctly; temperature may fluctuate or be inaccurate.

Safety first: Turn off power at the breaker. Allow the oven to cool fully before removing panels.

Step-by-step checks:

• Inspect sensor and harness: Access the sensor from inside the cavity and from the rear. Look for melted insulation or wires touching metal surfaces.
• Measure resistance: Disconnect the sensor and measure resistance. A very low reading (near 0 Ω) indicates a shorted sensor.
• Check for shorts to ground: With the sensor disconnected, measure resistance from each sensor terminal to the oven chassis. Any low resistance indicates a short in the harness.
• Dry connectors: If there are signs of moisture or steam intrusion at the connector, dry thoroughly and clean with electrical contact cleaner.

When to replace parts: Replace the oven temperature sensor if it is shorted. If the harness is damaged or shorted to chassis, repair or replace the sensor wiring harness. If all wiring and sensor are good, suspect the control board.