LG Refrigerator Error Code Er CO — What It Means & How to Fix It

What Does This Error Mean?

The Er CO error means there is a communication failure between the main control board and the display panel. The two circuit boards inside your LG refrigerator cannot talk to each other. This usually prevents the fridge from operating normally.

Affected Models

LRMVS3006S
LRFXS2503S
LFXS26973S
Most LG French door and side-by-side refrigerators

Common Causes

Loose or disconnected ribbon cable between the main board and display board
Power surge that damaged one or both circuit boards
Corroded or damaged wire harness connector pins
Faulty main control board (located at the back bottom of the fridge)
Faulty display control board (located behind the front panel)

How to Fix It

Unplug the refrigerator from the wall outlet for 5 minutes.

This performs a hard reset of both control boards.
Plug the refrigerator back in and wait for the display to light up.

If the display comes on normally and the error is gone, it was a temporary glitch.
Check if the fridge was recently moved or bumped hard.

A loose cable connection could have been jarred loose.
If the error returns, try unplugging for a full 30 minutes.

A longer reset sometimes helps clear stubborn communication errors.
If the error persists, call a technician to inspect the wiring and boards.

Do not attempt to open the control panels yourself — risk of electric shock.

When to Call a Professional

Communication errors almost always require professional diagnosis. A technician needs to test both boards to find which one failed. Contact LG support or a certified appliance repair service. Expect repair costs of $200–$500 depending on which board needs replacement.

Frequently Asked Questions

Is the Er CO error serious on an LG refrigerator?

Yes — this is one of the more serious LG fridge errors. Without communication between the boards, the fridge may not cool properly. The compressor and fans may stop running entirely. Move perishable food to a cooler and get the fridge serviced quickly.

Can a power surge cause the Er CO error?

Yes — power surges are a common cause of control board failures. A surge can damage the circuitry on one or both boards. Using a surge protector for your refrigerator can help prevent this. Note: some manufacturers advise plugging directly into the wall, so check your manual.

How much does it cost to replace a control board on an LG fridge?

The main control board part costs $100–$250. The display board costs $80–$200. Labor to diagnose and install is typically $100–$200. Total repair can range from $200–$500 depending on which board failed.