Lg Refrigerator Error Code: Er CO

This code shows that there is a communication error between the control board and the display.

The first and easiest step is to check for any loose wire connections in the wire harnesses connecting the display to the control board. If there are any, be sure to reconnect them tightly. Alternatively, unplug your unit for five minutes and see if this fixes your unit.

Moving on…

It is likely that your control board is faulty. To check this, first remove the control board and inspect it for bad(burnt) spots more so on the underside. Also, check for cracks or other signs of damage. If it is damaged, you will need to get a replacement OEM board for your refrigerator.

Speaking of replacement boards, have you recently replaced your control board? If yes, it is likely that you replaced it with a model that is not suited for your refrigerator. In this case, you will need to get a replacement control board that matches the model number of the control board that came with your refrigerator.