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Error code reference

Samsung Air Conditioner Error Code OUTDOOR_YELLOW_RED_ON

Outdoor sensor error (open/short)

Samsung codesSamsung air conditioner codes

Outdoor sensor error (open/short)

First step from the service manual

Check outdoor temperature sensor resistance values

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_RED_ON means on a Samsung air conditioner

The OUTDOOR_YELLOW_RED_ON error on a Samsung air conditioner indicates an outdoor sensor fault, specifically an open circuit or short circuit condition in one of the outdoor temperature sensors. These sensors are thermistors, meaning their electrical resistance changes predictably with temperature. The control board continuously monitors the resistance values from these sensors to regulate compressor operation, refrigerant flow, and defrost cycles. When the measured resistance falls outside the expected range for current ambient conditions, the system flags this error and may suspend operation to protect critical components.

An open circuit condition occurs when the sensor circuit is broken, typically due to a severed wire, corroded connector, or a failed thermistor that has gone to infinite resistance. A short circuit condition is the opposite, where the resistance drops to near zero, often caused by damaged insulation allowing wires to contact each other or the unit chassis. Both conditions produce readings the control board cannot interpret as valid temperature data.

Diagnosing this fault begins with measuring the outdoor temperature sensor resistance values using a multimeter and comparing them against the temperature-to-resistance curve specified for the unit. Inspecting wiring harnesses for physical damage, corrosion at connector pins, and moisture intrusion in the outdoor unit is also essential. Because the outdoor unit is exposed to weather, sensor wiring is particularly vulnerable to UV degradation, pest damage, and water ingress over time.

Source: manufacturer service documentation.

Common causes of OUTDOOR_YELLOW_RED_ON

  1. 01

    Failed outdoor thermistor

    Part replacement

    The thermistor itself has failed, producing resistance values that are either out of range or completely absent. This is confirmed by measuring sensor resistance with a multimeter and comparing to expected values at the current ambient temperature.

  2. 02

    Corroded or damaged wiring connector

    Wiring / connection

    Moisture and oxidation at the sensor connector pins can increase resistance or break continuity entirely. Inspect the harness connector at the outdoor control board and at the sensor for green or white corrosion deposits.

  3. 03

    Broken or pinched sensor wire

    Part replacement

    Physical damage to the sensor wiring, such as a pinched, cut, or rodent-chewed wire, creates an open circuit. Visually trace the sensor wiring through the outdoor unit and check for any points of wear or damage.

  4. 04

    Water intrusion into the outdoor unit

    Wiring / connection

    Water entering the outdoor unit can short sensor wiring against the chassis or other conductors. Check for signs of water pooling inside the unit and verify that drain paths are clear.

  5. 05

    Faulty outdoor control board

    Part replacement

    If the sensor and all wiring test within specification, the outdoor control board itself may have a damaged input circuit that is misreading the sensor signal. This is the least common cause and should only be concluded after all other components are ruled out.

See the test procedure for each cause

Frequently asked questions about OUTDOOR_YELLOW_RED_ON

What does OUTDOOR_YELLOW_RED_ON mean on a Samsung air_conditioner?
This error indicates that the outdoor unit has detected a fault in one or more of its outdoor temperature sensors. The fault is classified as either an open circuit, where continuity is lost, or a short circuit, where resistance drops to near zero. The control board cannot interpret either condition as a valid temperature reading, so it generates this alert. The system may limit or suspend operation until the sensor circuit is restored to a normal resistance range.
How do I fix the OUTDOOR_YELLOW_RED_ON error on my Samsung air conditioner?
Start by using a multimeter to measure the resistance of the outdoor temperature sensor and compare it to the expected value for the current ambient temperature. Inspect all sensor wiring and connector pins for corrosion, breaks, or moisture damage. If the sensor resistance is out of range and wiring is intact, replace the thermistor. If the sensor and wiring are both within specification, the outdoor control board may need further evaluation.
Is it safe to run my Samsung air conditioner with the OUTDOOR_YELLOW_RED_ON error active?
It is not recommended to continue running the unit with this error present. The outdoor temperature sensors are used by the control board to protect the compressor and manage defrost cycles. Operating without valid sensor data can lead to compressor damage or unsafe operating conditions. Address the fault before resuming normal use.
Will resetting my Samsung air conditioner clear the OUTDOOR_YELLOW_RED_ON error?
A power reset may temporarily clear the error display, but the code will return if the underlying sensor fault has not been repaired. Because the error is tied to a measured electrical condition in the sensor circuit, the control board will re-detect the fault as soon as it reads the sensor again. A reset alone is not a fix and should not be relied on as a solution.
How much does it cost to repair the OUTDOOR_YELLOW_RED_ON error on a Samsung air conditioner?
Repair costs vary depending on the root cause. A replacement outdoor thermistor is typically an inexpensive part, often in the range of $15 to $60 for the component alone. If professional labor is required for diagnosis and replacement, total costs generally fall between $100 and $300 depending on local rates and accessibility of the unit. A faulty outdoor control board is the most expensive scenario, with parts and labor potentially ranging from $300 to $600 or more.

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