GE oven shows F4 and may not start or may shut off unexpectedly

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

• Inspect sensor and wiring: Remove the oven sensor from inside the cavity and inspect the insulation and connector. Look for melted insulation or bare wires touching metal.
• Test sensor resistance: With the sensor disconnected, measure resistance at room temperature. A reading near 0 Ω indicates a shorted sensor; replace it.
• Check for shorts to ground: With the sensor disconnected, use a multimeter to check continuity between each sensor lead and the oven chassis. There should be no continuity. If there is, the harness is shorted and must be repaired or replaced.
• Dry connectors: If the oven was recently steam-cleaned or exposed to heavy moisture, dry the sensor connector and harness thoroughly before reassembling.