COLG · Refrigerator · Fridge

LG Refrigerator error code CO

Communication error between the main board and the display

Needs attention soon

Also written as Er CO

Quick answer

On LG Refrigerator (2010s onward), CO is a fault. It means communication error between the main board and the display. A first thing to check: Door harness or ribbon cable connector loose, corroded, or pinched in the hinge.

Applies to: LG Refrigerator; LG refrigerator codes · Refrigerator · 2010s onward
Type of code: Fault; Urgency: Needs attention soon
First safe check: Unplug the cabinet and check the display and the panel connectors at both ends of the door harness.

Checked 2026-09-26

What CO means on this model

The board behind the cabinet and the panel you are reading are not exchanging messages, so nothing the panel shows is reliable. There is no reset for this one, and the door harness and the board both need checking.

Symptoms you will notice

Display blank, dim, or showing a communication message
Panel shows a code with letters such as PC ER or PC CH
No settings respond from the panel
Fault appears after a power cut

Common causes

The code tells you what the control detected, not which part failed. These are the causes we see most often, roughly in order of likelihood:

Door harness or ribbon cable connector loose, corroded, or pinched in the hinge
Harness chafed where it flexes through the door hinge
Main board output failed
Display panel itself failed
Moisture or a spill at the top of the cabinet reaching the panel

What you can safely check

These are homeowner-level checks. None of them need you to open a live electrical compartment or work on gas.

Unplug the cabinet and check the display and the panel connectors at both ends of the door harness.
Open the hinge cover and look for a harness that is crushed or cut where the door swings.
Look for water staining around the top of the cabinet interior.

Do not do these

×Do not open the panel itself. It is not a serviceable part and it can hold a charge.
×Do not run the cabinet with a door harness pinched, since that is exactly how the fault reappears.

When to call a technician

Book a technician, do not keep resetting it

This fault will not clear on its own. Every power cycle gives the control one more failed attempt, and repeated attempts are what turn a cheap part replacement into a seized or contaminated system.

If the appliance has stopped mid-cycle, is making a noise you have not heard before, or smells burnt, stop reading here and call. Those are symptoms of something the fault code does not describe well enough.

Technician work. A visual check of the hinge harness with the power off is a reasonable owner task.

What it costs to fix

Parts

Door harness $60 to $200. Main board $150 to $450. Display panel $150 to $400.

Labor

One to two and a half hours.

DIY or technician