LG Refrigerator ER CO Error: Board Communication Error
LG refrigerator error — here’s what you need to know. The Er CO error code on your LG refrigerator indicates a communication failure between the main control board and the display or sub-board. This is a High severity issue. What Does Er CO Mean on an LG Refrigerator? LG refrigerators use a serial communication line […]
~30%
DIY Fixable
From $200
Typical Repair Cost
1–3 hours
Pro Repair Time
Quick Assessment
Answer to continue safely
Is it safe to keep using?
Maybe. The refrigerator may continue cooling in a limited mode, but temperature control is unreliable. Use with caution, monitor compartment temperatures with a thermometer, and avoid storing critical medications or large amounts of perishable food until resolved.
Can I reset the code?
Yes. A 10-minute power reset sometimes resolves a temporary communication glitch, especially after a power outage. If the error returns after the unit warms up or goes through a defrost cycle, hardware repair is needed.
When to stop immediately?
Stop if you notice: Display is completely non-functional and you cannot verify internal temperatures, Error appeared immediately after a power outage or lightning strike.
Symptoms You May Notice
Display Panel Shows Incorrect or Frozen Readings
Temperature displays show dashes, wrong numbers, or stop updating. Control buttons may become unresponsive. The display may go blank while the refrigerator continues running in background mode.
Refrigerator Enters Default or Limited Mode
The unit runs continuously at a fixed output or stops adjusting to temperature changes. Cooling may be inconsistent, with one compartment too cold and another not cold enough.
Repeated Beeping or Alert Tones
The refrigerator produces continuous or repeating alarm tones that cannot be silenced through the control panel. This is the unit alerting you that critical communication between boards has been lost.
Intermittent or unresponsive controls
Buttons or display elements stop responding, flicker, or behave erratically because signals between the control boards are disrupted or corrupted.
Possible Causes
Loose or Disconnected Wiring Harness
The ribbon cable or wire harness connecting the main board to the display board can work loose due to vibration over time. A partially seated connector interrupts the data signal intermittently or completely.
DIY PossiblePower Surge Damage to Control Board
A voltage spike — from a storm, power outage, or grid fluctuation — can damage the communication circuitry on the main or display board. The refrigerator may have been running normally before the outage and showed this error afterward.
Requires ProfessionalMoisture or Corrosion on Board Connectors
Condensation, a nearby water leak, or high humidity over time causes corrosion on the metal connector pins of the control boards. Corroded pins create resistance that garbles the communication signal.
Requires ProfessionalSafe Checks You Can Do
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1
Perform a Full Power Reset
Unplug the refrigerator from the wall outlet and wait 10 full minutes before plugging it back in. This allows capacitors on both boards to fully discharge and may restore communication. Watch the display on startup to see if the error clears.
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2
Check the Wiring Harness at the Hinge Area
On French door models, a wire harness runs through the top hinge from the door display board to the main board. Open and close the door slowly while watching the display — if the error flickers, a wire inside the hinge bundle is cracked or pinched.
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3
Check for Signs of Moisture Near the Control Board
Locate the main control board (typically behind the rear lower access panel or upper rear panel depending on model). Look for signs of water staining, rust-colored deposits, or corrosion on connector pins. Do not operate the refrigerator if moisture is present on the board.
When to Call a Professional
Contact a qualified technician if:
- Power reset does not clear the error after multiple attempts
- Wiring harness connectors are properly seated but error persists
- Visible corrosion or damage on the main or display control board
Need Professional Help?
Find qualified technicians in your area for proper diagnostics and repair.
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