LG Refrigerator Error Code Er CO

Er CO indicates a communication failure between the main control PCB and the display PCB inside your LG refrigerator. The two boards use a wired data link to coordinate all functions, and this code appears when that link is broken or degraded. The cause can be a damaged wire harness, a loose connector, or a failed transmitter or receiver component on either board.

A reset by unplugging the unit for a few minutes may temporarily clear the code if the fault was caused by a momentary signal dropout. However, if there is physical damage to the wiring or a component on either board has failed, the code will return once power is restored. A reset is a reasonable first step, but a thorough inspection of the harness and PCB components is still necessary if the code reappears.

Repair costs depend on the root cause. If only a wire harness needs to be replaced, parts and labor typically range from around $75 to $200. If a display PCB or main control PCB is required, costs can range from $150 to $400 or more depending on the specific board and labor rates in your area. Getting a diagnostic visit from a qualified technician first will help pinpoint the exact failed component before committing to a repair.

A homeowner comfortable with basic appliance repair can start by unplugging the refrigerator and inspecting the wire harness connectors between the two boards for looseness or visible damage. Reseating a loose connector may resolve the code. However, if the wiring is damaged or a PCB component has failed, replacing a harness or control board typically requires some technical experience and the correct replacement parts.

With an active Er CO error, the refrigerator may not respond correctly to temperature settings or operate its cooling system reliably, since the main PCB and display PCB cannot communicate properly. Continuing to run the unit in this state risks food safety due to unpredictable temperature control. It is best to address the fault promptly and avoid relying on the refrigerator to maintain safe temperatures until the issue is resolved.