mypros+
Error code reference

LG Microwave Error Code E-13

Sensor T1 max time error

LG codesLG microwave codes

Sensor T1 max time error - sensor did not detect expected humidity/temperature change within the allowed time.

First step from the service manual

Check if food was placed in the oven; do not heat without food inside.

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

MyPros+ Max

Get the full diagnostic procedure for E-13.

  • Step-by-step tests with expected resistance, voltage, and continuity values
  • Wiring diagram references and connector pinouts from the OEM service manual
  • Verified part numbers when replacement is required
Get the full procedure

$29/month · Cancel anytime · Or $9.95 3-day pass

What E-13 means on a LG microwave

The E-13 error on an LG microwave indicates a Sensor T1 maximum time error. This means the humidity/temperature sensor (designated T1) failed to detect the expected change in humidity or temperature within the time window the control board allows during a sensor cook cycle. When you run a sensor cooking program, the microwave monitors rising steam and heat from the food to determine cooking progress. If that rise does not occur within the allotted time, the board flags E-13 and halts the cycle.

The T1 sensor is typically a humidity sensor positioned inside the cavity that measures steam output from the food being cooked. For the sensor cook function to work correctly, food must be present in the oven and must be generating steam. Running a sensor cycle without food, or with food that is too dry, too small, or improperly covered, can prevent the sensor from registering a meaningful change, triggering the timeout error.

Beyond user error, hardware faults can also produce E-13. A failed or drifted T1 sensor will not respond to actual steam changes, causing the board to time out even when food is present. Wiring issues between the sensor and the control board, such as a loose connector or damaged harness, can interrupt the signal. In less common cases, a faulty control board may misread valid sensor data or fail to process it correctly. Diagnosis should start with confirming food was present, then move to inspecting the sensor and its wiring.

Source: manufacturer service documentation.

Common causes of E-13

  1. 01

    No food or insufficient food in the cavity

    Wiring / connection

    Running a sensor cook cycle without food, or with a very small or very dry food item, means the T1 sensor has no steam to detect and the cycle times out. Always ensure an appropriate amount of food is present before starting a sensor program.

  2. 02

    Failed or faulty T1 humidity sensor

    Part replacement

    If the T1 sensor has drifted out of spec or has failed entirely, it will not register steam changes even when food is cooking normally, causing the control board to reach its maximum wait time and trigger E-13. The sensor will need to be tested and replaced if defective.

  3. 03

    Loose or damaged sensor wiring harness

    Wiring / connection

    A disconnected connector or chafed wire between the T1 sensor and the control board can interrupt the signal, making the board behave as if no reading is coming in. Inspect the harness routing and connector seats carefully.

  4. 04

    Food covered too tightly or in a sealed container

    Wiring / connection

    If food is wrapped in a way that traps all steam inside the container, the sensor cannot detect rising humidity in the cavity. Venting the cover slightly allows steam to reach the sensor as intended.

  5. 05

    Faulty control board

    Part replacement

    In less common cases, the main control board may be unable to correctly process the incoming sensor signal, causing a false timeout even when the T1 sensor is functioning properly. This is usually diagnosed after the sensor and wiring have been confirmed good.

See the test procedure for each cause

Frequently asked questions about E-13

What does E-13 mean on a LG microwave?
E-13 is a Sensor T1 maximum time error. It means the humidity and temperature sensor inside the microwave did not detect the expected change during a sensor cook cycle within the allowed time limit. The most common reason is that no food, or insufficient food, was placed in the oven before the sensor cooking program was started. If food was present, the sensor or its wiring may be at fault.
Can I fix E-13 on my LG microwave myself?
If the error occurred because the microwave was run without food, you can simply place food inside and restart the cycle with no repair needed. If the error persists with food present, a technician or experienced DIYer should inspect the T1 sensor and its wiring harness. Replacing the sensor is a moderate-difficulty repair that requires disassembling the microwave cabinet. Always discharge the high-voltage capacitor before working inside any microwave.
Is it safe to keep using my microwave when E-13 appears?
The E-13 error halts the sensor cook cycle, so the microwave is not completing cooking as expected. You should not rely on sensor cooking programs until the issue is resolved, as food may be undercooked. Manual timed cooking modes may still function, but you should address the underlying fault before continued regular use.
Will resetting my LG microwave clear the E-13 error?
Unplugging the microwave for a minute and plugging it back in will clear the error code from the display. However, if the root cause is a faulty sensor or wiring problem, the error will return the next time a sensor cook cycle is attempted. A reset is only a lasting fix if the error was triggered by running the microwave without food.
How much does it cost to repair an LG microwave E-13 error?
If the fix is simply adjusting how food is placed or covered, there is no cost involved. If the T1 humidity sensor needs replacement, parts typically range from $20 to $60 depending on the model, plus labor if a technician performs the repair. A professional repair visit for this type of sensor fault generally runs in the range of $100 to $200 total, though costs vary by region and service provider.

Related LG microwave codes

All LG microwave codes
View all 84 LG microwave codes

78,000+ service manuals · 160,000+ error codes · 55+ brands

Get Started

$29/month · Cancel anytime · Or $9.95 3-day pass