Samsung Air Conditioner Error Code t1

The T1 error code on a Samsung air conditioner indicates a fault with the outdoor ambient temperature sensor, also called the OUT TEMP sensor. This sensor is a thermistor that changes its resistance based on the surrounding air temperature. The control PCB monitors the voltage signal produced across this sensor circuit to determine outdoor conditions. When the measured voltage rises above 4.9V, the system interprets this as an OPEN circuit condition, corresponding to a temperature reading below negative 50 degrees Celsius. When the voltage drops below 0.4V, the system interprets this as a SHORT circuit condition, corresponding to a temperature reading above 93 degrees Celsius. Both thresholds represent values that fall outside any realistic operating range, so the control board flags the T1 error to prevent incorrect system operation.

The outdoor temperature sensor is typically a two-wire NTC (negative temperature coefficient) thermistor mounted on the outdoor unit. It connects to the outdoor control PCB via a small plug-in connector. When the error appears, the first step is to inspect whether that connector has become physically separated from the PCB, as vibration or improper reassembly can cause this. If the connector is seated, measuring resistance across both terminals of the sensor will confirm whether the thermistor itself has failed open, failed short, or is reading within its expected resistance range for the current ambient temperature.

Common causes include a disconnected sensor connector, a thermistor that has failed due to age or moisture exposure, or damaged wiring between the sensor and the PCB. Corrosion at the connector pins can also introduce enough resistance change to push the voltage signal outside the acceptable window. In some cases, the outdoor PCB itself may be the root cause if it is unable to correctly read an otherwise good sensor signal.