LG Refrigerator Error Code Er Co2

Er Co2 indicates a communication error between the Sub PCB Micom and the Display Micom on your LG refrigerator. The two control boards have lost the ability to exchange data properly. This is usually caused by a loose wiring connection at the display board connector or a failure in the transistor-based Tx/Rx communication circuit between the boards.

Er Co2 reflects a control communication failure, which can affect the refrigerator's ability to regulate temperatures and respond to user commands properly. Running the unit in this state risks food spoilage if cooling control is compromised. It is best to address the error promptly rather than continuing normal use.

If the fix is simply reseating a loose connector, there is no parts cost involved. Replacing a display board or sub PCB typically runs anywhere from $80 to $250 or more depending on the specific model and parts sourcing. Adding a professional technician's labor will bring the total repair cost higher, generally in the range of $150 to $400 depending on your area and the parts required.

A knowledgeable DIYer can start by unplugging the refrigerator and checking for loose or disconnected connectors between the display and sub board, specifically at the CON101 connector on the display. If reseating connections does not resolve the issue, diagnosing the 12V supply voltage and testing the Tx/Rx transistor circuit requires a multimeter and some familiarity with electronics. Board replacement is straightforward but confirming which board has failed first will save unnecessary parts costs.

A power reset by unplugging the refrigerator for a few minutes may temporarily clear the error if the cause was a transient communication glitch. However, if a loose connector, failed transistor, or board fault is present, the error will return shortly after the reset. A reset alone is not a repair and should be followed by proper diagnostics.