LG Refrigerator Error Code PC Er

PC Er indicates a communication error between the Main MICOM control board and the Panel MICOM control board. The Main MICOM sends a communication signal to the Panel MICOM and receives no response within 10 seconds, triggering this code. On RSG5B series models, the same fault appears as 'PC E' on the display. The error points to a breakdown somewhere in the signal path between the two boards.

A PC Er code means the communication between the main control board and the display panel has broken down, which can affect how reliably the refrigerator responds to temperature commands and user inputs. It is not a high-voltage safety hazard, but continued operation with this fault may result in unreliable cooling or an inability to adjust settings correctly. Monitoring food temperatures closely is advisable, and prompt repair is recommended.

Repair costs vary depending on which component is at fault. If only a connector needs reseating, labor charges may be the primary expense. A replacement Panel PCB typically runs in the range of $80 to $200 for the part, while a Main PCB can range from $150 to $350 or more, depending on the model. Adding a technician's diagnostic fee and labor, total repair costs commonly fall between $150 and $500 depending on which board requires replacement and your location.

A homeowner or DIYer can start by unplugging the refrigerator and inspecting the wiring harness connectors between the Main PCB and Panel PCB for looseness or corrosion, then reseating them. Beyond that, accurate diagnosis requires an oscilloscope to trace the communication signal, which is a technician-level tool. If connectors are intact and the error persists, one or both control boards will need to be replaced, which most homeowners will want a technician to handle.

Unplugging the refrigerator for a few minutes and restarting it may temporarily clear the code if the fault was caused by a transient software glitch or a brief signal interruption. However, if the underlying cause is a loose connector, damaged wiring, or a failed PCB, the PC Er code will return. A reset does not repair a hardware fault, so the code reappearing after a restart confirms a physical issue that needs further diagnosis.