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Error code reference

LG Refrigerator Error Code Cp

Linear compressor failed starting.

LG codesLG refrigerator codes

Linear compressor failed starting.

First step from the service manual

Check compressor resistance at CON2 housing (1-5 ohms expected); check OLP and wiring.

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

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What Cp means on a LG refrigerator

The Cp error code on an LG refrigerator indicates that the linear compressor has failed to start. LG's linear compressor operates differently from conventional reciprocating compressors: it uses a linear piston driven by electromagnetic force rather than a crankshaft, and the control board monitors the startup sequence closely. If the compressor does not reach operating parameters within the expected window after a start attempt, the board flags the Cp fault and halts further attempts to protect the system from damage.

The first diagnostic step is to check the compressor winding resistance at the CON2 connector on the compressor housing. Expected resistance across the terminals falls in the 1 to 5 ohm range. A reading outside this range, whether open or shorted, points to internal compressor failure. In addition to the windings, the overload protector (OLP) must be checked. The OLP is a thermal safety device mounted on the compressor body; if it has tripped or failed, it will interrupt the start circuit even when the compressor itself is intact.

Wiring integrity between the control board and the compressor is also a common failure point. Corroded pins, loose connectors, or damaged harness wires at the CON2 housing can prevent the start signal or feedback signal from completing the circuit properly. Technicians should inspect all wiring for continuity and signs of heat damage before condemning the compressor, as a wiring fix is far less costly than compressor replacement.

Source: manufacturer service documentation.

Common causes of Cp

  1. 01

    Failed linear compressor

    Part replacement

    The compressor windings may be open or shorted, which will show as a resistance reading outside the 1 to 5 ohm range at the CON2 connector. Internal mechanical seizure is also possible and results in the same fault.

  2. 02

    Tripped or failed overload protector (OLP)

    Part replacement

    The OLP is a thermal cutoff device attached to the compressor body. If it has tripped due to overheating or has failed internally, it will block the start circuit and trigger the Cp code even when the compressor itself is undamaged.

  3. 03

    Wiring harness or connector damage at CON2

    Wiring / connection

    Corroded, loose, or broken wires at the CON2 compressor connector can prevent the start signal from reaching the compressor or block feedback from returning to the control board. Inspect all pins and wires for continuity and physical damage.

  4. 04

    Faulty compressor control board

    Part replacement

    The inverter or compressor control board is responsible for generating the drive signal to the linear compressor. A failed board may not deliver the correct waveform or voltage needed to initiate startup, resulting in the Cp fault.

See the test procedure for each cause

Frequently asked questions about Cp

What does Cp mean on a LG refrigerator?
The Cp code means the linear compressor failed to start during its startup sequence. The refrigerator's control board monitors the compressor's startup and throws this code when the compressor does not reach operating parameters in time. This fault will cause the unit to stop cooling. Diagnosis involves checking compressor winding resistance at the CON2 connector, the overload protector, and the wiring harness.
Can I fix the Cp error code myself?
Some causes of the Cp code, such as a loose or corroded connector at the CON2 housing, can be addressed by a knowledgeable DIYer who is comfortable working around appliance wiring. However, testing compressor resistance with a multimeter and replacing the OLP, compressor, or control board typically requires technical experience and proper tools. Because the compressor circuit involves capacitors and high-voltage components, caution is strongly advised.
Is it safe to keep using my refrigerator with a Cp error?
No. When the Cp code is active, the compressor is not running and the refrigerator is not cooling. Food safety is at risk if the temperature inside rises above safe levels. The refrigerator should be emptied of perishables and service should be arranged promptly.
How much does it cost to repair the Cp error on an LG refrigerator?
Repair costs vary significantly depending on the root cause. Wiring or OLP repairs may run between $100 and $250 including labor. Control board replacement typically falls in the $200 to $450 range. Compressor replacement is the most expensive outcome, often ranging from $400 to $900 or more depending on labor rates and part availability.
Will resetting the refrigerator clear the Cp error code?
A power reset may temporarily clear the Cp code and allow the refrigerator to attempt another startup. However, if the underlying cause, such as a failed compressor, a bad OLP, or a wiring fault, has not been corrected, the code will return. A reset is useful for ruling out a one-time glitch but is not a fix for a genuine component failure.

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