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Error code reference

LG Refrigerator Error Code E1+E2

Communication error between main PCB and display PCB

LG codesLG refrigerator codes

Communication error between main PCB and display PCB — no communication for 30 seconds continuously.

First step from the service manual

Check wiring and connectors between main PCB and display PCB (DC 12V, GND, Send, Receive lines).

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What E1+E2 means on a LG refrigerator

The E1+E2 error code on an LG refrigerator indicates a communication failure between the main PCB (control board) and the display PCB (user interface board). Specifically, the error triggers when the two boards fail to exchange data signals for a continuous period of 30 seconds. The communication link between these boards relies on four lines: DC 12V power, GND (ground), Send, and Receive. If any of these lines is interrupted, shorted, or carrying corrupted signals, the boards lose their ability to communicate and the error is logged.

The most common entry point for diagnosis is the wiring harness and connectors that run between the main PCB and the display PCB. Loose connector pins, damaged wiring, corrosion at the connector terminals, or a pinched harness can all break the communication circuit. Because the Send and Receive lines carry data signals, even intermittent contact issues can cause the 30-second dropout threshold to be reached and the code to appear.

If the wiring and connectors check out, the fault may lie within one of the two boards themselves. A failed main PCB may stop transmitting on the Send line, while a failed display PCB may fail to respond on the Receive line. In either case, the functional board detects the silence and throws the error. Power supply issues affecting the 12V line feeding the display PCB can also produce this symptom, so verifying the voltage at the connector is an important early step.

Source: manufacturer service documentation.

Common causes of E1+E2

  1. 01

    Loose or disconnected wiring harness connector

    Wiring / connection

    The connector linking the main PCB and display PCB may have worked loose over time due to vibration. Inspect both ends of the harness for connectors that are not fully seated or have bent pins.

  2. 02

    Damaged or pinched wiring harness

    Part replacement

    The harness running between the two boards can become pinched during installation or chafed against a sharp edge, breaking one or more of the four communication lines. Visually trace the full length of the harness and check for visible damage.

  3. 03

    Corroded or contaminated connector terminals

    Wiring / connection

    Moisture inside the refrigerator cabinet can reach connector terminals and cause oxidation, increasing resistance on the Send, Receive, or power lines enough to disrupt communication. Check terminals for discoloration or buildup and clean or replace as needed.

  4. 04

    Failed display PCB

    Part replacement

    If the display PCB has an internal failure, it will stop responding to signals from the main PCB on the Receive line, causing the main board to log the communication timeout. Confirm power and signal are present at the display PCB connector before condemning the board.

  5. 05

    Failed main PCB

    Part replacement

    A failed main control board may stop transmitting data on the Send line entirely, preventing any communication with the display PCB. This is typically diagnosed after confirming the wiring harness and display PCB are in good condition.

See the test procedure for each cause

Frequently asked questions about E1+E2

What does E1+E2 mean on a LG refrigerator?
The E1+E2 error code means the main PCB and the display PCB have lost communication with each other for at least 30 seconds continuously. These two boards communicate over a four-wire connection carrying 12V power, ground, and separate Send and Receive data lines. When that link is broken, the refrigerator flags the error. The root cause is usually a wiring or connector issue, though a failed board is also possible.
Will resetting my LG refrigerator clear the E1+E2 error?
A power reset may temporarily clear the E1+E2 code, but if the underlying wiring or board fault is still present, the error will return once the 30-second communication dropout occurs again. A reset is a useful first step to confirm whether the fault is intermittent or persistent. For a permanent fix, the physical cause of the communication failure needs to be identified and repaired.
How do I fix the E1+E2 error on my LG refrigerator?
Start by inspecting the wiring harness and connectors between the main PCB and display PCB, checking all four lines: DC 12V, GND, Send, and Receive. Make sure all connectors are fully seated, pins are not bent or corroded, and the harness is not pinched or damaged. If the wiring is intact, verify that 12V is actually present at the display PCB connector. If power and wiring are confirmed good, the display PCB or main PCB may need to be replaced.
Is it safe to keep using my LG refrigerator when the E1+E2 error is showing?
The E1+E2 error affects communication between the control and display boards, which can impair your ability to adjust settings and monitor the refrigerator's status. Depending on the severity of the fault, cooling functions may also be disrupted if the main PCB cannot receive input correctly. It is best to address the error promptly rather than continue using the appliance, especially to avoid potential food spoilage if cooling is compromised.
How much does it cost to fix an E1+E2 error on an LG refrigerator?
If the fix is simply reseating a connector or cleaning corroded terminals, the cost may be minimal, covering only your time or a basic service call fee. Replacing a wiring harness typically runs in the range of $50 to $150 for parts, plus labor. A replacement display PCB or main PCB can range from $100 to $300 or more depending on the model, with additional labor costs if a technician performs the repair.

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