LG Refrigerator Er CO: Communication Error Fix

The Er CO error indicates a communication breakdown between the main control board and the display/user interface panel. These two boards must communicate constantly to regulate temperature and respond to user inputs.

What Causes Er CO

1. Unstable power supply (most common) — Surges, fluctuations, brownouts
2. Power strip or extension cord — Can’t provide stable power for refrigerators
3. Wire disconnection — Between main board and display board
4. Display PCB failure — User interface board malfunction
5. Main control board failure — Primary controller malfunction

Symptoms

• Error code “Er CO” or “E CO” on display
• Display may be unresponsive
• Controls may not respond to button presses
• LED lights may blink erratically
• Temperature adjustments may not save

The Power Reset Fix

LG’s recommended first step resolves approximately 60-70% of Er CO cases.

Step 1: Unplug Completely

Disconnect the power cord from the wall outlet. If you can’t reach the plug, turn off the circuit breaker.

Step 2: Wait 5 Minutes

This allows capacitors to discharge and both control boards to fully reset. Shorter waits may not clear the error.

Step 3: Check Your Power Source

Do:

• Use a dedicated wall outlet (nothing else plugged into it)
• Plug directly into the wall outlet

Don’t:

• Use power strips
• Use extension cords
• Share the outlet with other appliances
• Use outlets on GFI circuits with other loads

Step 4: Restore Power

Plug the refrigerator back in or turn on the breaker. The display should initialize normally.

Step 5: Monitor

Watch for the error to return:

• Error clears and doesn’t return = Power issue was the cause
• Error returns within hours = Board replacement likely needed
• Error returns immediately = Wire disconnection or board failure

If Power Reset Doesn’t Work

Check Wire Connections

If you’re comfortable accessing the control boards:

1. Unplug refrigerator
2. Locate the main control board (usually at the back, bottom)
3. Locate the display board (behind the control panel)
4. Check the ribbon cable or wire harness connecting them
5. Ensure connections are secure at both ends
6. Look for visible damage, corrosion, or pinched wires

Board Replacement

If connections are good but error persists, one of the boards has failed:

Component	Typical Cost	Notes
Display board	$100-200	Usually easier to access
Main control board	$150-350	More complex replacement
Professional labor	$100-200	If not DIY

Board replacement is technically DIY-possible but involves working with electrical components. Many owners prefer professional service.

Power Quality Issues

If Er CO keeps returning even after board replacement, the problem may be your home’s electrical supply.

Signs of Power Quality Issues

• Er CO appears during storms
• Other electronics acting erratically
• Lights flickering
• Breakers tripping frequently

Solutions

• Have an electrician check your home’s electrical system
• Consider a surge protector rated for refrigerators
• Ensure the outlet is properly grounded

Model Coverage

Er CO appears on all LG refrigerator types with digital displays:

• French Door: LRMVS, LRMVC, LRFXS series
• Side-by-Side: LRSXS, LRSVS series
• InstaView: All models
• Bottom/Top Freezer: Models with digital displays

When to Call a Tech

Contact LG support (1-800-243-0000) if:

• Power reset doesn’t clear the error
• Error returns immediately after reset
• You’re not comfortable checking wire connections
• Display remains completely unresponsive
• Multiple error codes appear

Sources

For official LG support:

• LG Er CO Troubleshooting
• LG Refrigerator Error Code List

Related Guides

• LG Refrigerator Error Codes: Complete Guide
• How to Reset an LG Refrigerator
• LG Linear Compressor Problems