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Error code reference

Maytag Oven Error Code 3d12

Temperature sensor failure (open) in lower oven; sensor resistance greater than infinite ohms.

Maytag codesMaytag oven codes

Temperature sensor failure (open) in lower oven; sensor resistance greater than infinite ohms.

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What 3d12 means on a Maytag oven

Error code 3d12 indicates the control board has detected an open circuit in the lower oven temperature sensor circuit. Specifically, the sensor is reading infinite resistance (open ohms), meaning the control board receives no usable signal from the RTD or thermistor used to monitor lower cavity temperature. This condition disables all cooking functions for the lower oven cavity, as the board cannot regulate heat without a temperature reference. The fault persists until the sensor circuit reads within the expected resistance range.

For homeowners, the lower oven temperature sensor is a small probe mounted inside the oven cavity, usually at the back wall. Its job is to continuously report the oven's internal temperature to the control board so it can cycle the heating elements on and off accurately. When the sensor circuit goes open, it means that signal is completely lost. This could be due to a failed sensor, a broken wire in the harness connecting the sensor to the board, or a loose or corroded connector. Because the oven cannot safely regulate temperature without this data, it shuts down cooking functions entirely rather than risk overheating.

Source: manufacturer service documentation.

Common causes of 3d12

  1. 01

    Failed lower oven temperature sensor

    Part replacement

    The sensor element itself has broken internally, causing its resistance to read infinite ohms. This is the most common cause of a 3d12 code and is confirmed by checking continuity across the sensor terminals with a multimeter.

  2. 02

    Broken or damaged wire in the sensor harness

    Part replacement

    A wire in the harness running from the lower oven sensor to the control board has broken or burned through, creating an open circuit. Visually inspect the harness for charred insulation, pinch points, or breaks near connectors.

  3. 03

    Loose or corroded sensor connector

    Wiring / connection

    The connector at either the sensor end or the control board end has worked loose or corroded, interrupting the circuit. Unplugging and firmly reseating the connector can sometimes resolve this without parts replacement.

  4. 04

    Failed control board

    Part replacement

    If the sensor and harness both test good with a multimeter, the control board's sensor input circuit may have failed, preventing it from reading a valid resistance value. This is the least likely cause and should only be suspected after ruling out the sensor and wiring.

See the test procedure for each cause

Frequently asked questions about 3d12

What does error code 3d12 mean on a Maytag oven?
Error code 3d12 means the control board detected an open circuit in the lower oven temperature sensor. The sensor is reading infinite resistance, which tells the board it has lost all temperature data for the lower cavity. As a result, the oven disables all cooking functions for that cavity until the fault is resolved.
Can I still use my Maytag oven with a 3d12 error code?
No. When 3d12 is active, all cook functions for the lower oven cavity are disabled by the control board. The oven will not heat because it cannot safely regulate temperature without a working sensor signal. If your unit is a double oven, the upper cavity may still function independently, but the lower oven will remain inoperable until the sensor issue is corrected.
How do I fix error code 3d12 on a Maytag oven?
Start by checking the lower oven temperature sensor for continuity using a multimeter set to the resistance or continuity mode. Disconnect the sensor leads and probe the terminals. A healthy sensor reads a finite resistance value, typically around 1080 to 1100 ohms at room temperature. An open reading means infinite resistance, and the sensor must be replaced. If the sensor tests good, inspect the wiring harness from the sensor to the control board for breaks or burned sections, and check that all connectors are seated firmly.
How much does it cost to fix a 3d12 error on a Maytag oven?
A replacement lower oven temperature sensor typically costs between $20 and $60 for the part, and replacing it is a manageable DIY repair requiring only a screwdriver and a multimeter. If the wiring harness is damaged, harness repair or replacement can cost $30 to $80 in parts. If the control board has failed, that part generally runs $150 to $300 or more. Professional labor typically adds $100 to $200 to any of these repairs depending on your region.
How do I test the lower oven temperature sensor to diagnose a 3d12 code?
Disconnect power to the oven at the breaker before beginning. Locate the lower oven sensor probe at the back wall of the lower cavity and unplug its harness connector. Set a multimeter to measure resistance and probe both sensor terminals. At room temperature, a functioning sensor reads approximately 1080 to 1100 ohms. A reading of infinite ohms or OL confirms the sensor is open and needs replacement. If the sensor reads correctly, reconnect it and check the harness wiring and connectors for damage before suspecting the control board.

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