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Error code reference

LG Microwave Error Code E-12

Gas sensor short error

LG codesLG microwave codes

Gas sensor short error — sensor terminals or related connector/soldering parts are shorted.

First step from the service manual

Check if both terminals of the sensor are slightly shorted; remove the shorted part of the temperature sensor.

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

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  • Wiring diagram references and connector pinouts from the OEM service manual
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What E-12 means on a LG microwave

The E-12 error code on an LG microwave indicates a gas sensor short error. Specifically, the internal gas sensor circuit is detecting a short condition across its terminals, meaning current is flowing along an unintended path between the two sensor leads. This sensor monitors gas concentration or air quality conditions inside the microwave cavity, and when its output signal falls outside expected parameters due to a short, the appliance control board registers the fault and halts normal operation to prevent inaccurate readings or potential safety concerns.

The short condition can originate at several points in the sensor circuit. The sensor terminals themselves may be physically damaged, corroded, or bridged by debris or moisture. The wiring harness connector that links the sensor to the control board is another common failure point, where pins can become bent, contaminated, or pushed together. Solder joints on the sensor's PCB mounting pads can also crack and reflow in ways that create unintended continuity between adjacent contacts, particularly after repeated heat cycling inside the microwave cavity.

The primary diagnostic approach is to measure resistance across both terminals of the gas sensor. A shorted sensor will show near-zero ohms, well below the normal operating resistance range for the component. The technician should first inspect the connector for visible damage or contamination, then test the sensor in isolation after disconnecting the harness. If the short is confirmed at the sensor body itself, the sensor must be removed and replaced. If the short is in the connector or soldering, repair or replacement of that specific section of the wiring may resolve the fault.

Source: manufacturer service documentation.

Common causes of E-12

  1. 01

    Faulty or internally shorted gas sensor

    Part replacement

    The sensor itself may have failed internally, creating a short between its terminals. Testing resistance across the sensor leads will show near-zero ohms if the sensor body has failed.

  2. 02

    Damaged or contaminated wiring harness connector

    Wiring / connection

    The connector joining the sensor to the control board can accumulate grease, moisture, or physical damage that bridges the terminal pins. Visually inspect the connector for bent pins, corrosion, or foreign material.

  3. 03

    Defective solder joints on the sensor mounting

    Wiring / connection

    Heat cycling inside the microwave can cause solder joints at the sensor's PCB pads to crack and reflow, creating shorts between adjacent contacts. Inspect the solder points under magnification for bridges or irregular bead shapes.

  4. 04

    Moisture intrusion at the sensor circuit

    Part replacement

    Steam or condensation inside the microwave cavity can reach the sensor terminals and create a temporary or permanent conductive path between them. Look for signs of water damage or corrosion on the sensor and its surrounding components.

  5. 05

    Pinched or damaged sensor wiring

    Wiring / connection

    The wire leads running from the sensor to the control board connector can become pinched against the chassis or heat-damaged, causing insulation breakdown and a short to ground or between conductors.

See the test procedure for each cause

Frequently asked questions about E-12

What does E-12 mean on a LG microwave?
E-12 on an LG microwave indicates a gas sensor short error. The control board has detected that the two terminals of the gas sensor are shorted, meaning there is unintended electrical continuity between them. This could be caused by a failed sensor, a damaged connector, compromised solder joints, or wiring damage. The microwave will not operate normally until the fault is resolved.
Can I fix the E-12 error on my LG microwave myself?
Some aspects of this repair are DIY-accessible, such as inspecting and cleaning the sensor connector or checking for visibly damaged wiring. However, working inside a microwave involves exposure to high-voltage capacitors that can retain a lethal charge even when unplugged, so the capacitor must be safely discharged before touching any internal components. If the sensor itself has failed and needs replacement, a technician with microwave service experience is recommended.
Is it safe to use my LG microwave while it shows E-12?
No, you should not attempt to use the microwave while E-12 is active. The error indicates a sensor circuit fault, and the appliance may have already disabled itself to prevent operation under this condition. Continuing to attempt operation with a known electrical fault is not advisable, and the underlying short should be diagnosed and corrected first.
Will resetting my LG microwave clear the E-12 error?
A simple power reset by unplugging the microwave for a minute or two may temporarily clear the displayed code, but the error will return if the underlying short condition in the sensor circuit is still present. The fault must be physically corrected by repairing or replacing the shorted component before the error will stay clear.
How much does it cost to repair an E-12 error on an LG microwave?
Repair costs vary depending on the root cause. If only the sensor connector needs cleaning or a solder joint needs reflow, costs are minimal and mostly involve labor. If the gas sensor itself requires replacement, parts and labor combined typically range from around $80 to $200 or more depending on the model and service rates in your area. In some cases, if the microwave is older, the repair cost may approach the price of a new unit, which is worth factoring into the decision.

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