Samsung Range Error Code C0

The C0 error code on a Samsung range indicates a fault with the top temperature sensor, also called the upper oven or cavity sensor. This sensor is a thermistor that feeds analog resistance data to the control board, which converts it to a digital A/D value. When that A/D value rises above 252, the board interprets the circuit as open, meaning the sensor or its wiring has lost continuity. When the A/D value drops below 10, the board reads this as a short circuit in the sensor loop. An open condition can also trigger if the ambient temperature surrounding the sensor falls below -10 degrees Celsius, though this is rare in normal kitchen environments.

The top sensor works by changing its electrical resistance in response to temperature. The PCB reads this resistance as a voltage that it converts to a digital value within an expected range. A value outside that range in either direction tells the board that the sensor signal is no longer reliable, at which point the C0 code is set and normal operation is interrupted. This is a safety mechanism to prevent the oven from running without accurate temperature feedback.

The three main sources of this fault are a defective thermistor sensor, damaged or misrouted wiring in the sensor harness, and a defective PCB. The sensor itself can fail due to thermal stress over time, producing either an open or shorted resistance reading. Wiring problems including pinched, corroded, or disconnected connectors are also common causes. If the sensor and wiring both check out, the PCB input circuit may have failed and will need replacement.