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LG Refrigerator Error Code CO

Reviewed by the ApplianceErrors Editorial Team · Verified against manufacturer service documentation · Last verified: June 11, 2026
⚠ Medium Severity 🔧🔧 Moderate DIY

Communication error — main board and display board not talking

The most common cause of the CO error on a LG refrigerator is loose or damaged harness in the door hinge (~40% of cases); start with: power cycle.

💰 DIY cost: $0–$140 👨‍🔧 Pro cost: $160–$320 Save $160+ by doing it yourself
LG Refrigerator error code CO on the display panel
How the CO code appears on a LG refrigerator display

What Does Error Code CO Mean on a LG Refrigerator?

Communication error — main board and display board not talking.

CO fires when the main control board and the dispenser/display board fail to maintain their serial data handshake. The main board watches for expected message packets; when they drop out or arrive corrupted, it logs the communication fault. Cooling generally continues on the last stored settings while the panel and dispenser go unresponsive. This distinguishes CO from sensor or fan faults like Er rF or FS, which report a specific component reading rather than a total loss of board-to-board dialogue.

Models affected: LG French-door and multi-door refrigerators with a through-the-door display/dispenser panel, including models such as LFXS26973S, LFXS28968S, LMXS28626S, LRFDS3016S and LRFVS3006S
What owners report: Owners commonly report CO appearing intermittently, often after the door has been opened and closed many times, which points to the flexing hinge harness. A simple unplug-for-two-minutes power cycle sometimes clears a transient version of the code, but if it returns quickly the connector or a board is usually at fault.

What Causes Error Code CO?

Here are the most common causes in order of frequency. Start with the most likely cause before moving to the next:

  1. 1
    Loose or damaged harness in the door hinge 40% of cases
  2. 2
    Display board failure 25% of cases
  3. 3
    Main board communication circuit fault 20% of cases
  4. 4
    Water intrusion corroding a connector 15% of cases

How to Fix LG Refrigerator Error Code CO

🔧🔧 Moderate DIY Est. time: 30–60 min
⚡ Safety first: Unplug the appliance before opening any panels or touching internal components.
  1. 1

    Power cycle

    Unplug for 2 minutes — communication re-handshakes on boot and a transient glitch clears.

  2. 2

    Inspect the hinge harness

    Unplug the unit, remove the top hinge cover, and check the door wiring loom for broken conductors or unseated plugs; reseat firmly.

    ⚠️ Unplug the refrigerator before opening hinge covers and connectors.
  3. 3

    Replace the display board

    If the harness is intact, the display board is the more common failure of the two boards.

    🔩 LG display/dispenser board ($60–$140)

How to Reset Error Code CO

Unplug for 2 minutes and restore power. If CO returns immediately, the fault is hardware, not state.

Note: If the error returns after resetting, the underlying issue has not been resolved. Work through the fix steps above.

Full LG refrigerator reset guide → Enter diagnostic mode →

Did this guide fix your appliance?

When to Call a Professional

Distinguishing a bad display board from a bad main board requires swap testing — a technician can do this in one visit.

Average professional repair cost for this issue: $160–$320

Related Error Codes

Er rF
Refrigerator fan error — fresh-food compartment fan not running
⚠ High Severity
FS
Freezer sensor fault — freezer thermistor circuit open or shorted
⚠ Medium Severity

Find Replacement Parts

Use these links to find the exact replacement parts for your LG Refrigerator:

🔩
Search PartSelect
LG Refrigerator repair parts
🔧
Search RepairClinic
Step-by-step video guides

External links — ApplianceErrors.com is not affiliated with these retailers.

More LG Refrigerator Error Codes

Er FF Freezer fan error — fan motor not operating Er dH Defrost heater error — defrost cycle not completing Er CF Condenser fan motor error Er FS Freezer temperature sensor error Er IS Ice maker sensor failure Er IF Ice maker fan error

Frequently Asked Questions

Can I keep using my LG Refrigerator when error CO appears? +
You often can for a cycle or two, but the electrical issue behind CO will keep interrupting normal operation until it is fixed. Plan the repair rather than ignoring the code.
What most commonly causes CO on a LG Refrigerator? +
Across reported LG refrigerator repairs, the most frequent is loose or damaged harness in the door hinge (40% of cases), display board failure (25%), then main board communication circuit fault (20%). Check them in that order before replacing any parts.
CO keeps coming back after a reset — what should I check next? +
A reset only clears the stored CO fault; if it returns, the electrical problem is still present. Move on to the physical checks — power cycle, then inspect the hinge harness — since the code will reappear until the root cause is resolved. This is a moderate job — a multimeter and some disassembly are usually involved.
How much does it cost to fix LG Refrigerator error CO? +
A DIY repair typically runs $0–$140 in parts, versus $160–$320 for a professional service call, so handling it yourself saves around $160. Expect the work to take roughly 30–60 minutes.
Which LG Refrigerator models show error CO? +
CO is documented on LG French-door and multi-door refrigerators with a through-the-door display/dispenser panel, including models such as LFXS26973S, LFXS28968S, LMXS28626S, LRFDS3016S and LRFVS3006S. Other units sharing the same control platform can display it too, so the fixes here generally transfer across the series.

Sources & References

Content verified against manufacturer service documentation. Last verified: June 11, 2026.

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