Samsung Air Conditioner Error Code t3

The Samsung T3 error code indicates a fault with the PWM discharge temperature sensor in the outdoor unit. This sensor monitors the refrigerant discharge temperature at the compressor outlet, which is a critical measurement for protecting the compressor from overheating and ensuring efficient operation. The control board triggers this fault when the sensor signal voltage falls outside the acceptable operating range: a reading above 4.95V corresponds to an apparent temperature below -30°C (open circuit condition), while a reading below 0.5V corresponds to an apparent temperature above 151°C (short circuit condition). Importantly, the error is only flagged when the outdoor ambient temperature is above -10°C, which helps the system distinguish genuine sensor faults from expected low-temperature behavior in cold climates.

The discharge temperature sensor is a negative temperature coefficient (NTC) thermistor. As temperature increases, its resistance decreases, which directly affects the voltage the PCB reads across the sensor circuit. An open circuit, caused by a broken wire, failed sensor, or disconnected connector, pushes the voltage toward the upper threshold. A short circuit, caused by damaged insulation or a shorted sensor element, pulls the voltage toward the lower threshold. Both conditions cause the board to lose accurate temperature data and trigger a protective shutdown.

Diagnosis begins by physically inspecting the sensor connector at the outdoor PCB for separation, corrosion, or damaged pins. After confirming the connector is secure, measuring resistance across both sensor terminals will reveal whether the thermistor itself has failed. A significantly out-of-range resistance reading at a known ambient temperature points to a failed sensor requiring replacement, while normal resistance with a fault voltage suggests wiring or PCB issues.