--- title: "Refrigerator error code CO" description: "LG refrigerator error code CO: There are two boards in this cabinet: the main control behind or beneath the machine, and the display in the door." url: "https://lgmiami.support/error-codes/refrigerator-communication/" date_modified: "2026-09-05" Appliance type: "Refrigerators" --- # Refrigerator error code CO ### What CO means on this make There are two boards in this cabinet: the main control behind or beneath the machine, and the display in the door. They talk over a harness that runs through the hinge, and this code says the conversation has stopped. It is worth knowing where that harness goes, because a hinge is a thing that moves thousands of times a year and a wire that runs through one is a wire under stress. The machine usually keeps cooling — the main board can run alone — but you lose control of it, and any setting you change at the display does not arrive. ### The other ways LG prints this one CO · Er CO · E CO LG publishes a condition and then every string that can stand for it, and which one your machine shows depends on the panel it was built with — OE, E03 and E21 are one condition on a washer, and Er dS, F dS and r dS are one sensor on different evaporators. They are one page here, so whichever of them you searched for, this is the right page. ### Where this appears, and why not to clear it On the appliance’s own display. LG reports errors two ways: machines with a digital display show a code, and the laundry machines without one blink their indicator lights instead. Both are published by the maker and both are on this site. Photograph what the panel shows before cutting the power. On a refrigerator you can also force the last code back onto the display by holding Freezer Temperature and Express Frz together for three seconds — LG documents that, and it is the one thing that makes a first visit more useful. A code that has been reset is information a technician no longer has. ### What to do about it - Cut the power at the wall for five minutes. A genuine communication drop-out often clears. - Check whether the machine is still cooling. If it is, this is urgent but not an emergency. - Note whether the display is blank or lit. A lit display that cannot change anything is the classic version. - Book it. This one is not a homeowner repair — the harness runs inside the hinge. ### Where this goes next The job this usually becomes is [appliance control board repair](/services/appliance-control-board-repair/), and that page carries a starting figure and the reasons that move it. If it turns out to be nothing — and on this make a real share of these are modes, reminders and settings rather than problems — the visit ends there and you pay the diagnostic and nothing else, or call [(305) 419-0291](tel:+13054190291) and describe what the panel is doing before booking anything. Communication between the boards What this one means What CO means on this make There are two boards in this cabinet: the main control behind or beneath the machine, and the display in the door. They talk over a harness that runs through the hinge, and this code says the conversation has stopped. It is worth knowing where that harness goes, because a hinge is a thing that moves thousands of times a year and a wire that runs through one is a wire under stress. The machine usually keeps cooling — the main board can run alone — but you lose control of it, and any setting you change at the display does not arrive. The other ways LG prints this one CO · Er CO · E CO LG publishes a condition and then every string that can stand for it, and which one your machine shows depends on the panel it was built with — OE, E03 and E21 are one condition on a washer, and Er dS, F dS and r dS are one sensor on different evaporators. They are one page here, so whichever of them you searched for, this is the right page. Where this appears, and why not to clear it On the appliance’s own display. LG reports errors two ways: machines with a digital display show a code, and the laundry machines without one blink their indicator lights instead. Both are published by the maker and both are on this site. Photograph what the panel shows before cutting the power. On a refrigerator you can also force the last code back onto the display by holding Freezer Temperature and Express Frz together for three seconds — LG documents that, and it is the one thing that makes a first visit more useful. A code that has been reset is information a technician no longer has. What to do about it Cut the power at the wall for five minutes. A genuine communication drop-out often clears. Check whether the machine is still cooling. If it is, this is urgent but not an emergency. Note whether the display is blank or lit. A lit display that cannot change anything is the classic version. Book it. This one is not a homeowner repair — the harness runs inside the hinge. Where this goes next The job this usually becomes is appliance control board repair, and that page carries a starting figure and the reasons that move it. If it turns out to be nothing — and on this make a real share of these are modes, reminders and settings rather than problems — the visit ends there and you pay the diagnostic and nothing else, or call [(305) 419-0291](tel:+13054190291) and describe what the panel is doing before booking anything. --- **[Read full article: Refrigerator error code CO](https://lgmiami.support/error-codes/refrigerator-communication/)**