GE Oven F4: Temperature Sensor Shorted — Mirror Image of F3

F4 is F3's opposite: the sensor reads abnormally LOW resistance instead of infinite. The sensor wire is shorting to itself or to the sensor housing. Same part fixes both codes — GE WB20X10109 ($12-$25).

F3 vs F4: Opposite Failures

• F3 (open): Wire broke. Reads infinity. More common. Self-clean thermal stress
• F4 (short): Wire contacts itself/housing. Reads near-zero. Less common. Moisture intrusion or physical damage

Why F4 Happens Less Often

Sensors typically fail open (wire breaks from fatigue) rather than short. F4 causes are more specific:

Moisture inside the housing: Steam from cooking or a cavity spill enters through a compromised probe seal. Water creates a conductive bridge between the sensor wire and the grounding sleeve, dropping resistance dramatically.

Bent probe damage: If someone bent the probe back straight after it was knocked, the internal wire may now touch the outer sheath at the bend point.

Wiring harness short: Melted insulation where the sensor wires run near hot surfaces allows the two conductors to touch. This is a harness fault, not a sensor fault — the wires read as shorted to the ERC even though the sensor itself is fine.

Diagnosis

1. Disconnect the sensor connector
2. Measure resistance: below 200 ohms = sensor shorted internally. Replace it.
3. Normal reading (1,080-1,100 ohms) = the sensor is fine. The short is in the wiring harness.
4. Inspect the wire run for melted insulation near hot components
5. Also measure each sensor wire to chassis ground: should read OL. Any reading = ground fault in wiring

Parts and Pricing

Professional repair: $125-$275. Same quick repair as F3 if the sensor itself is the cause.

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F4 on your GE oven? Same sensor, same quick fix as F3. Sacramento area. Book service.