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LG·refrigeratorhigh severity
LG Error Code Er CO
Communication error
Common Causes
- 1Main board failure
- 2Wiring issue
Step-by-Step Troubleshooting
- 1
Perform a hard reset by unplugging the refrigerator for 10 minutes, then plug back in — this clears transient communication faults between the main PCB and display board
- 2
Open the control panel housing (top of the unit or behind the fresh food door) and inspect the ribbon cable connecting the display board to the main control board
- 3
Check the main control board (located at the rear bottom) for visible burn marks, swollen capacitors, or corroded solder joints
- 4
Test voltage between the main board and display board communication pins — LG uses a serial data protocol requiring 5V DC reference
- 5
If both boards appear intact, the wire harness routing through the door hinge area may have fractured from repeated opening — inspect for damaged insulation
Pro Diagnostic Tip
On LG ThinQ-enabled models, Er CO frequently indicates the WiFi module is interfering with the inter-board serial bus. Disconnecting the WiFi module connector on the main board and restarting can confirm whether the ThinQ module is the culprit before ordering a $180+ main board.
You Might Also Notice
- •Display panel is blank or unresponsive
- •Temperature controls do not respond to button presses
- •Unit runs but cannot be adjusted
- •Error appears intermittently and clears after power cycle
Parts, Cost & Difficulty
Repair Difficulty
Professional OnlyEstimated Repair Cost
$250–$450
Parts + labor. Free diagnosis with repair.
Parts That May Need Replacement
EBR84433501 (Main Control Board)EBR82870703 (Display Control Board)EAD63905901 (Wire Harness Assembly)
Do You Have the Right Tools?
Refrigerant gauges ($200+), vacuum pump ($250), leak detector ($150), and EPA-certified recovery equipment. Our technician arrives with $15K+ in professional tools — your diagnostic is free.
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Get Professional Help Now
Error code Er CO is a high-severity issue that can cause further damage to your refrigerator if left unresolved. A licensed technician can diagnose and fix it the same day.
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Frequently Asked Questions
What does LG error code Er CO mean?
LG error code Er CO indicates: Communication error. This is a high-severity issue affecting your refrigerator.
How do I fix LG error code Er CO?
Perform a hard reset by unplugging the refrigerator for 10 minutes, then plug back in — this clears transient communication faults between the main PCB and display board Then, Open the control panel housing (top of the unit or behind the fresh food door) and inspect the ribbon cable connecting the display board to the main control board Then, Check the main control board (located at the rear bottom) for visible burn marks, swollen capacitors, or corroded solder joints There are 2 more steps — see the full troubleshooting guide above. This repair typically requires professional tools and expertise.
How do I know if my refrigerator has error Er CO?
Besides the error code on the display, common signs include: Display panel is blank or unresponsive; Temperature controls do not respond to button presses; Unit runs but cannot be adjusted. If you notice any of these symptoms, check your refrigerator's display panel for error code Er CO.
How much does it cost to fix LG Er CO?
Repair costs for LG Er CO typically range from $250 to $450 depending on the specific cause and parts needed. EasyBear offers free diagnosis when you proceed with the repair. Call (415) 795-7300 for a same-day appointment.