Error code reference

GE Oven Error Code F33

Lower oven sensor circuit fault related to oven sensor resistance thresholds.

GE codesGE oven codes

Lower oven sensor circuit fault related to oven sensor resistance thresholds.

First step from the service manual

Check resistance of oven sensor circuit on ERC (T012) at CN300 pin 1 to 8 W to W/R, or on Machine Control lower oven board connector J300 pins 1 to 2 W to W/R.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What F33 means on a GE oven

The F33 error code indicates the Electronic Range Control (ERC) has detected a fault in the lower oven sensor circuit. Specifically, the control has measured resistance in the sensor circuit that falls outside the expected thresholds. The fault is read at ERC connector CN300 pins 1 to 8 (W to W/R wires) or at the Machine Control lower oven board connector J300 pins 1 to 2. This points to a problem somewhere in the sensor circuit loop, including the sensor itself, the wiring harness, or the control board connection.

For homeowners, the lower oven sensor is a small probe mounted inside the oven cavity that continuously reports the temperature to the control board. When the board reads a resistance value from this sensor that is too high or too low, it cannot trust the temperature data and throws the F33 code to prevent unsafe operation. The oven will typically stop functioning normally until the fault is resolved.

The first diagnostic step is to measure the actual resistance across the sensor circuit at the specified connectors. A properly functioning GE oven sensor typically reads around 1080 to 1100 ohms at room temperature. Readings significantly above or below this range confirm a faulty sensor, while a correct resistance reading at the sensor but a fault still present may indicate a wiring issue or a failing control board.

Source: manufacturer service documentation.

Common causes of F33

  1. 01

    Failed lower oven temperature sensor

    Part replacement

    The oven sensor itself has drifted out of its resistance specification or failed open or short. This is the most common cause of F33 and is confirmed by measuring resistance directly at the sensor terminals versus at the ERC connector.

  2. 02

    Damaged or open wiring harness between sensor and control board

    Part replacement

    The W and W/R wires running from the lower oven sensor to CN300 or J300 can develop breaks, burns, or loose terminals, causing resistance readings outside acceptable thresholds even if the sensor itself is functioning correctly.

  3. 03

    Loose or corroded connector at CN300 or J300

    Wiring / connection

    Poor contact at ERC connector CN300 pins 1 to 8 or Machine Control lower oven board connector J300 pins 1 to 2 can introduce false resistance readings into the circuit, triggering F33 without any underlying component failure.

  4. 04

    Faulty ERC or Machine Control lower oven board

    Part replacement

    If the sensor and wiring harness both check out within specification at the connector pins, the control board itself may be misreading the circuit. This is the least likely cause and should only be suspected after the sensor and wiring are confirmed good.

See the test procedure for each cause

Frequently asked questions about F33

What does F33 mean on a GE oven?
F33 on a GE oven means the control board has detected that the lower oven sensor circuit is reading a resistance value outside the acceptable range. The board monitors this resistance to determine oven temperature, and when it falls outside expected thresholds, it flags the fault and interrupts normal operation. The sensor probe, the wiring harness, or the connector at the control board are the most likely sources of the problem.
How do I fix F33 on a GE oven?
Start by measuring the resistance of the lower oven sensor circuit at ERC connector CN300 pin 1 to 8 (W to W/R) or at Machine Control lower oven board connector J300 pins 1 to 2. A healthy sensor reads approximately 1080 to 1100 ohms at room temperature. If the reading is far outside this range, replace the lower oven sensor. If the sensor reads correctly at its own terminals but not at the board connector, inspect the wiring harness for breaks or burns and check the connector pins for corrosion or looseness.
Can I still use my GE oven with the F33 code active?
Using the oven while F33 is active is not recommended. The error means the control board cannot reliably read the lower oven temperature, which means the oven may overheat or fail to reach and hold the correct temperature without triggering any safety shutoff. Operating the oven in this condition risks food safety issues and potential damage to the appliance.
How much does it cost to fix F33 on a GE oven?
If the lower oven sensor is the cause, replacement sensors are typically priced between $20 and $60 for the part, and the repair is manageable for a careful DIYer since most sensors are secured with one or two screws and connect via a simple harness plug. If the wiring harness needs repair or replacement, parts and labor can run $100 to $200. A control board replacement is the most expensive scenario, with boards often costing $150 to $350 plus labor if you use a technician.
How do I test the lower oven sensor on my GE oven to diagnose F33?
Unplug the oven and disconnect the sensor from the wiring harness. Set a multimeter to the ohms setting and measure across the two sensor terminals. At room temperature, a good GE oven sensor reads roughly 1080 to 1100 ohms. A reading near zero indicates a shorted sensor, while an infinite or very high reading indicates an open sensor. Either condition confirms the sensor needs replacement. If the sensor reads correctly on its own but the error persists, measure resistance at the connector pins on the control board to identify a wiring issue.

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