Frigidaire Refrigerator Error Code Er rS

The Er rS error code on a Frigidaire refrigerator indicates a fault in the refrigerator compartment temperature sensor. This sensor is a thermistor, a resistive component whose electrical resistance changes predictably with temperature. The control board monitors this resistance to determine the current temperature inside the refrigerator compartment. When the board detects a resistance value that falls outside the expected range, either due to an open circuit (disconnection) or a short circuit, it triggers the Er rS code and may lose the ability to regulate cooling accurately.

The two primary failure modes are a broken or disconnected wire harness and a failed thermistor itself. A disconnected sensor wire causes the circuit to read an open condition, presenting infinite resistance to the control board. A shorted sensor, where wires contact each other or the thermistor fails internally, causes abnormally low resistance. Both conditions are outside the normal operating range and flag the error. Physical damage to the wire harness, corrosion at connector pins, or a thermistor that has degraded over time are the most frequent root causes.

Diagnosis should begin by inspecting each sensor wire connection for looseness, corrosion, or visible damage. If all connections are secure, the thermistor itself should be tested with a multimeter to confirm its resistance matches expected values at a known temperature. If the resistance is out of range or reads open or zero, the sensor requires replacement. The control board is rarely the cause of this code but should be considered if a verified good sensor and intact wiring still produce the error.