LG Refrigerator Error Code UART COMMUNICATION ERROR

The UART COMMUNICATION ERROR on an LG refrigerator indicates a failure in the serial communication link between the main control board and the PLC (Power Line Communication) modem. UART stands for Universal Asynchronous Receiver-Transmitter, a hardware communication protocol used to exchange data between internal components. The PLC modem, when present, enables the refrigerator to communicate over the home's power line network, often supporting smart home integration or diagnostic telemetry. When the control board attempts to establish this communication and receives no valid response, the UART error is triggered.

The most important context for this code is that not all LG refrigerator models are equipped with a PLC modem. On units that do not include this component, the error may appear without indicating any actual fault or functional problem with the refrigerator. In those cases, the error can be safely disregarded, as the control board may simply be polling for a modem that was never installed. No cooling, compressor, or safety functions are typically compromised by this error alone.

On models that do include a PLC modem, the error points to a loose or disconnected harness connector at the modem, a damaged communication cable, or a failed modem module itself. The diagnostic process begins with physically verifying that the PLC modem is properly seated and connected to the main board. If connections are secure and the error persists, the modem itself may need to be tested or replaced.