Samsung Air Conditioner Error Code OUTDOOR_YELLOW_RED_FLICKER_GREEN_ON

The OUTDOOR_YELLOW_RED_FLICKER_GREEN_ON error code on a Samsung air conditioner indicates a deice sensor fault, specifically an open circuit or short circuit condition in the defrost temperature sensor. This sensor monitors the temperature of the outdoor unit's heat exchanger during heating operation, allowing the control board to detect ice buildup and trigger defrost cycles at appropriate intervals. When the sensor reading falls outside the expected resistance range, or the signal is absent entirely, the outdoor unit's LED display pattern changes to yellow and red flickering with a solid green, signaling the fault to the technician.

The deice sensor connects to the outdoor unit's main control board at connector CN52, pins 3 and 4. An open circuit fault typically results from a broken sensor wire, a disconnected connector, or a failed sensor element where resistance has risen beyond the measurable range. A short circuit fault occurs when the sensor wiring contacts ground or another conductor, pulling the resistance reading to near zero. Both conditions cause the control board to lose accurate temperature data for the heat exchanger, which can lead to the unit suspending heating operation as a safety measure.

Diagnosis begins with a physical inspection of the CN52 connector at pins 3 and 4, checking for corrosion, bent pins, or loose connections. If the connector appears intact, the sensor itself should be tested with a multimeter to measure resistance across its terminals. A healthy NTC thermistor sensor will show a resistance value that varies with temperature. Readings of zero ohms or infinite resistance confirm a short or open fault respectively, indicating sensor replacement is required.