Samsung Air Conditioner Error Code E253

Error code E253 on a Samsung air conditioner indicates a fault detected in the fixed compressor discharge temperature sensor circuit. The discharge temperature sensor monitors the temperature of refrigerant gas exiting the compressor, which is a critical measurement for protecting the compressor from overheating and ensuring efficient operation. When the control PCB detects a signal from this sensor that falls outside the expected resistance range, it flags E253 to prevent potential compressor damage.

The fault is specifically categorized as a wire open or short condition, meaning the sensor circuit has either lost continuity entirely (open) or has an unintended low-resistance connection (short). These two fault types produce opposite electrical symptoms: an open circuit typically drives the measured resistance to infinity or out of range high, while a short circuit pulls resistance toward zero. The PCB continuously monitors the sensor's resistance value, which varies predictably with temperature, so either extreme signals a wiring or sensor failure.

The first diagnostic step is to check whether the sensor connector has become disconnected from the PCB, as vibration during operation can loosen plugs over time. If the connector is seated, measure resistance across the sensor terminals to determine whether the sensor itself has failed or whether the wiring between the sensor and PCB is damaged. A broken wire, corroded terminal, pinched harness, or a failed sensor element are the most common sources of this fault.