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Error code reference

LG Refrigerator Error Code 85

Compressor low-voltage error

LG codesLG refrigerator codes

Compressor low-voltage error — input AC lower than 106V or R517 (DCLINK resistor) is shorted.

First step from the service manual

Check resistance of R517.

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

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What 85 means on a LG refrigerator

Error code 85 on an LG refrigerator indicates a compressor low-voltage fault. The inverter control board monitors the AC input voltage supplied to the compressor drive circuit. When that input voltage drops below 106V AC, the board registers an undervoltage condition and throws code 85 to protect the compressor from operating under damaging electrical conditions. Low input voltage can cause excessive current draw, overheating, and premature compressor failure, so this shutdown is a protective measure built into the inverter system.

The second trigger for this code is a shorted R517 resistor, also called the DCLINK resistor. This component is located on the inverter control board and is part of the DC link voltage sensing circuit. When R517 shorts, it sends a false low-voltage signal to the board's processor, causing code 85 to appear even if the incoming AC voltage is perfectly normal. Because the code can come from two very different sources, a targeted diagnostic approach is required to avoid unnecessary part replacement.

The first diagnostic step is to measure the resistance of R517 directly on the inverter board. A shorted resistor will show near-zero resistance instead of its rated value. If R517 checks out, the next step is to measure the actual AC input voltage at the compressor inverter board under load conditions. Voltage that reads below 106V points to a supply issue, which could stem from a weak household circuit, a failing outlet, extension cord use, or problems upstream in the home's electrical panel.

Source: manufacturer service documentation.

Common causes of 85

  1. 01

    Shorted R517 DCLINK resistor

    Part replacement

    The R517 resistor on the inverter board can short internally, causing the board to falsely detect a low-voltage condition even when AC input is normal. Check resistance across R517; a shorted component will read near zero ohms.

  2. 02

    Low household AC input voltage

    Wiring / connection

    If the AC supply voltage at the refrigerator's outlet falls below 106V, the inverter board will trigger code 85. Measure voltage at the outlet under load to confirm; causes can include a weak circuit breaker, loose wiring in the panel, or high demand on the circuit.

  3. 03

    Faulty or overloaded outlet or circuit

    Wiring / connection

    A worn outlet, a shared circuit under heavy load, or the use of an extension cord can drop voltage below the 106V threshold required by the inverter. Plug the refrigerator directly into a dedicated outlet and measure voltage to rule this out.

  4. 04

    Failed inverter control board

    Part replacement

    If R517 is shorted and cannot be repaired independently, or if the board shows other signs of damage such as burned traces or bulging capacitors, the entire inverter control board may need replacement.

  5. 05

    Loose or corroded wiring connections at the inverter board

    Wiring / connection

    Loose connectors or corroded terminals between the power supply and the inverter board can cause intermittent voltage drops that trigger code 85. Inspect all power connections to the board for secure seating and signs of corrosion or heat damage.

See the test procedure for each cause

Frequently asked questions about 85

What does 85 mean on a LG refrigerator?
Error code 85 on an LG refrigerator is a compressor low-voltage error. It triggers when the AC input voltage to the compressor inverter drops below 106V, or when the R517 DCLINK resistor on the inverter board is shorted. The refrigerator shuts down the compressor to prevent damage from running under inadequate voltage. Diagnosing the R517 resistor is the recommended first step.
Can I fix error code 85 on my LG refrigerator myself?
Some causes of error 85 can be addressed without professional help. Checking that the refrigerator is plugged directly into a dedicated outlet and measuring the outlet voltage are safe first steps for a knowledgeable DIYer. However, testing and replacing the R517 resistor or the inverter control board involves working with inverter circuitry and requires appropriate electrical safety knowledge and tools. If you are not comfortable working with control boards, a qualified technician should handle the repair.
Is error code 85 on an LG refrigerator dangerous?
Error code 85 itself is a protective shutdown, meaning the refrigerator has already detected a problem and stopped the compressor to prevent further damage. The underlying cause, particularly low household voltage or a shorted board component, should be addressed promptly. Low voltage conditions can stress other appliances on the same circuit as well. Have a qualified electrician check your home wiring if the outlet voltage is confirmed to be below 106V.
Will resetting my LG refrigerator clear error code 85?
A power reset may temporarily clear the error display, but code 85 will return if the underlying cause is not corrected. If R517 remains shorted or the input voltage remains below 106V, the inverter board will detect the fault again and shut the compressor down. A reset should only be used after completing diagnostics and making any necessary repairs to confirm the fault has been resolved.
How much does it cost to repair error code 85 on an LG refrigerator?
Repair costs vary depending on the root cause. If the issue is low household voltage requiring an electrician, expect to pay somewhere in the range of $100 to $300 or more depending on the scope of the electrical work. Inverter control board replacement, if needed, typically runs between $150 and $400 including parts and labor. If a technician can replace only the R517 resistor as a component-level repair, the cost may be lower, though not all shops offer board-level soldering repairs.

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