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Error code reference

Samsung Air Conditioner Error Code OUTDOOR_YELLOW_GREEN_RED_ON

4-Way valve error

Samsung codesSamsung air conditioner codes

4-Way valve error

First step from the service manual

Check 4-way valve wiring to control board; replace valve if wiring is normal

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

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  • Wiring diagram references and connector pinouts from the OEM service manual
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What OUTDOOR_YELLOW_GREEN_RED_ON means on a Samsung air conditioner

The OUTDOOR_YELLOW_GREEN_RED_ON error code on a Samsung air conditioner indicates a 4-way valve error in the outdoor unit. The 4-way valve is a reversing valve that controls the direction of refrigerant flow through the system. In cooling mode, refrigerant flows in one direction, and when the system switches to heating mode (in heat pump configurations), the valve shifts to reverse the flow. When the control board detects that the 4-way valve is not operating as commanded, or receives feedback inconsistent with the expected valve position, this error is triggered and displayed via the outdoor unit LED indicator pattern of yellow, green, and red LEDs illuminated simultaneously.

The most common causes of this error fall into two categories: wiring faults and valve mechanical failure. Wiring issues include loose connectors at the valve solenoid or at the outdoor control board, broken wire leads, or corroded terminals that prevent the control signal from reaching the valve coil. If the solenoid coil is not receiving the correct voltage signal, the valve plunger will not shift position, causing a mismatch between the commanded and actual refrigerant flow path. Resistance across the solenoid coil can be measured to determine if the coil itself has failed open or shorted.

If wiring inspection and electrical testing confirm that the control signal is being delivered correctly but the valve still fails to operate, the valve itself has likely failed mechanically or the coil has burned out. A stuck or seized 4-way valve can also result from refrigerant system contamination or pressure imbalances. In such cases, the valve assembly requires physical replacement, which involves recovering refrigerant, unsoldering the valve from the refrigerant lines, and installing a new unit.

Source: manufacturer service documentation.

Common causes of OUTDOOR_YELLOW_GREEN_RED_ON

  1. 01

    Loose or disconnected wiring at the valve solenoid

    Wiring / connection

    The wiring harness connecting the 4-way valve solenoid to the outdoor control board can become loose, corroded, or disconnected over time. Inspect the connector at both the solenoid terminal and the board for secure seating and clean contact surfaces.

  2. 02

    Faulty solenoid coil

    Part replacement

    The solenoid coil that drives the 4-way valve can burn out or develop an open or short circuit, preventing the valve from shifting. Measuring resistance across the coil terminals will reveal if the coil has failed.

  3. 03

    Mechanically stuck or seized valve

    Part replacement

    The internal slide or piston of the 4-way valve can become stuck due to debris, refrigerant contamination, or pressure-related wear. A stuck valve will not respond to correct electrical signals and requires full valve replacement.

  4. 04

    Damaged wiring harness between board and valve

    Wiring / connection

    Wire leads running through the outdoor unit cabinet can become pinched, chafed, or broken, interrupting the control signal. A visual inspection and continuity test of each wire in the harness will identify breaks.

  5. 05

    Outdoor control board failure

    Part replacement

    If the control board is not sending the correct output signal to the 4-way valve solenoid, the valve will not operate even if it is mechanically sound. This is typically diagnosed after wiring and valve coil have been confirmed good.

See the test procedure for each cause

Frequently asked questions about OUTDOOR_YELLOW_GREEN_RED_ON

What does OUTDOOR_YELLOW_GREEN_RED_ON mean on a Samsung air conditioner?
This error code indicates a 4-way valve error in the outdoor unit. The 4-way valve controls which direction refrigerant flows through the system, allowing the unit to switch between heating and cooling modes. Samsung's outdoor unit LED indicators display a simultaneous yellow, green, and red pattern to signal this specific fault. The error means the control board has detected that the valve is not operating as expected.
Can I fix a Samsung 4-way valve error myself?
Some steps, such as inspecting wiring connections and checking for loose or corroded terminals at the valve solenoid, can be performed by a knowledgeable DIYer with basic electrical tools. However, if the valve coil or the valve body itself needs replacement, refrigerant recovery and line unsoldering are required, which must be performed by an EPA-certified technician. Starting with wiring inspection is a safe and appropriate first step before committing to parts replacement.
Is it safe to run my Samsung air conditioner with the OUTDOOR_YELLOW_GREEN_RED_ON error active?
Operating the unit while this error is active is not recommended. A malfunctioning 4-way valve can cause the system to run in the wrong mode or place abnormal stress on the compressor and refrigerant circuit. Continued operation under these conditions risks additional component damage. The unit should be inspected and the fault resolved before resuming normal use.
Will resetting my Samsung air conditioner clear the OUTDOOR_YELLOW_GREEN_RED_ON error?
A power reset may temporarily clear the error display, but if the underlying fault with the 4-way valve or its wiring is still present, the error will return once the system attempts to operate the valve again. Resetting without diagnosing and repairing the root cause is not a lasting fix. The valve wiring and coil must be inspected and repaired or replaced as needed.
How much does it cost to repair a Samsung 4-way valve error?
Repair costs vary depending on what component has failed. If only a wiring repair or connector replacement is needed, costs are typically lower, often in the range of $75 to $200 for a service call and labor. If the 4-way valve itself must be replaced, parts and labor combined can range from $300 to $700 or more, depending on the unit model and local labor rates. Refrigerant recovery and recharge add to the cost when valve replacement is required.

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