Samsung Air Conditioner Error Code E313

The E313 error code on a Samsung air conditioner indicates a fault with the SUMP TEMP FIXED 2 sensor, specifically an open or short circuit condition detected when the outdoor ambient temperature is above -10°C. This sensor monitors the sump or base pan temperature within the outdoor unit, providing thermal data that the control system uses to manage defrost cycles and protect compressor components. Because the error is conditioned on outdoor temperatures above -10°C, the system can distinguish this fault from normal low-temperature sensor behavior, making it a reliable indicator of an actual electrical or physical sensor failure rather than an environmental reading anomaly.

The fault is classified as either open or short, meaning the sensor circuit has either lost continuity entirely or has developed a direct short to ground or another conductor. An open circuit typically occurs when the sensor wire breaks, a connector separates from the PCB, or the sensor element itself fails internally. A short circuit usually results from damaged insulation on the sensor wiring, moisture intrusion causing current leakage, or a failed thermistor that collapses to near-zero resistance. The PCB interprets either condition as a sensor reading outside the valid operating range and triggers E313 to halt normal operation and prevent potential damage.

Diagnosis begins by physically inspecting the sensor connector at the PCB to confirm it is fully seated and free from corrosion or bent pins. If the connector is secure, resistance measurement across the sensor terminals should be performed. A properly functioning NTC thermistor will show a measurable resistance value that corresponds to the current temperature. A reading of zero ohms or infinite resistance confirms a short or open condition respectively, pointing to either wiring harness damage or a failed sensor requiring replacement.