Maytag Microwave Error Code E12

E12 means the control board detected a short circuit in the gas sensor circuit. The board monitors the sensor's electrical signal during operation, and when it falls outside the acceptable range due to a short, the unit displays E12 and stops running. The fault can be in the sensor connector, the wiring harness, the sensor itself, or in rare cases the PCB assembly.

No. When E12 is active, the microwave has shut down operation because it cannot confirm the gas sensor circuit is functioning correctly. Running the appliance in this state bypasses a safety monitoring function. Do not attempt to use the microwave until the fault is diagnosed and repaired.

Yes, and this is the first thing to check. A disconnected or partially seated connector at the gas sensor creates an abnormal circuit condition that the control board interprets as a short, triggering E12. Before ordering any parts, unplug the unit, access the sensor wiring, and firmly reseat all connectors along the harness. This costs nothing and resolves the error in some cases.

Start by unplugging the microwave, then remove the outer casing and locate the gas sensor and its wiring harness. Check that the connector is fully seated at both the sensor and the PCB. Inspect the harness for any pinched, chafed, or burnt wiring. If the connector and wiring look intact, use a multimeter to test the sensor's resistance and compare it to the service manual spec. Replace the sensor if it reads a short, or replace the PCB if the sensor and wiring are both good.

If the fix is a reseated connector, there is no parts cost and only your time. A replacement gas sensor typically runs $20 to $60 depending on the model. A replacement PCB assembly is the most expensive repair, often ranging from $80 to $200 or more for the part alone. If you hire a technician, expect a service call fee of $75 to $150 on top of parts, which can make PCB replacement approach or exceed the cost of a new mid-range microwave.