LG Washer Error Code 1S

The 1S error code on an LG washer indicates a Micro Controller operational error in the upper washer unit. It is a system-level fault meaning the main PCB assembly has detected an internal failure in its own processing logic. This error points directly to the control board rather than an external sensor or component. The recommended first step is to replace the PCB assembly.

A power cycle reset may temporarily clear the 1S error, but because it indicates a Micro Controller operational error at the hardware level, the fault will typically return. A reset alone is not a reliable fix for this code. If the error persists after unplugging the washer for several minutes and restoring power, PCB replacement is the appropriate next step.

The cost to repair a 1S error depends primarily on the price of the replacement PCB assembly and labor if a technician is used. PCB assemblies for LG washers typically range from around 80 to 250 dollars depending on the model. Professional labor to diagnose and replace the board can add another 100 to 200 dollars. Sourcing the correct board for your specific model is important to ensure compatibility.

The 1S error requires replacing the main PCB assembly, which is an intermediate to advanced repair. A knowledgeable DIYer comfortable working with appliance electronics can perform this repair by disconnecting power, accessing the control board, and swapping the assembly. However, if you are not comfortable working with control board components, a qualified technician is recommended to ensure the correct board is sourced and installed safely.

It is not advisable to continue using the washer while the 1S error is active. A microcontroller operational error means the control board cannot reliably manage washer functions, which could result in incomplete cycles, unexpected behavior, or further damage to other components. The washer should remain out of service until the PCB assembly has been replaced and the error is resolved.