LG Microwave Error Code Error-01

The LG microwave Error-01 code indicates a fault detected during the sensor cook or temperature sensing process. This error is directly tied to the humidity or temperature sensor circuit, which the microwave relies on to monitor cooking conditions and automatically adjust power levels and cook times. When the control board cannot read a valid signal from the sensor, or detects a signal that falls outside expected parameters, it triggers this error and halts the sensor cook function.

The most common root causes involve the shield wire that connects the sensor to the control circuit. An incorrectly routed or improperly connected shield wire can introduce signal interference or a complete loss of continuity, causing the board to register a fault. Similarly, a loose shield wire connector at either the sensor end or the board end will produce the same result. Resistance values at the sensor connector that fall outside the acceptable range will also trigger Error-01, so verifying resistance with a multimeter is a key part of diagnosis.

A secondary but frequently overlooked cause is contamination on the sensor filter itself. Grease, food debris, or moisture buildup on the sensor filter can impair the sensor's ability to read humidity or temperature accurately, producing erratic or out-of-range readings that the control board interprets as a sensor error. Cleaning the filter and rechecking the shield wire connection and resistance are the first steps before replacing any components.