Maytag Refrigerator Error Code OC

The OC error code on a Maytag refrigerator indicates that the control board has detected an open circuit condition on the CZT (Convertible Zone Temperature) thermistor during the CZT test mode. A thermistor is a temperature-sensitive resistor that changes its resistance value based on the surrounding temperature. An open circuit means the electrical path through the thermistor circuit is completely broken, producing a signal the board interprets as an out-of-range or absent reading. This prevents the refrigerator from accurately monitoring and controlling the temperature in the convertible zone compartment.

The most common causes of an open circuit in a thermistor circuit are physical damage to the wiring harness, a disconnected or corroded connector, or a failed thermistor component itself. Because the code appears during CZT test mode specifically, the fault is localized to the thermistor circuit serving that zone rather than the main refrigerator or freezer sections. Vibration over time can loosen connectors, and moisture inside the cabinet can accelerate corrosion at terminal points.

Diagnosis should begin by inspecting all wiring and connectors associated with the CZT thermistor, looking for broken wires, backed-out terminals, or visible corrosion. If the wiring checks out visually, resistance testing of the thermistor itself can confirm whether the component has failed internally. A healthy thermistor will show a measurable resistance value that shifts with temperature changes. An open thermistor will show infinite resistance on a multimeter, confirming component failure.