GE Refrigerator Error Code 03

Error code 03 on a GE refrigerator indicates a fault in the refrigerator compartment evaporator defrost sensor circuit. This sensor monitors the temperature of the evaporator coil during and after defrost cycles. The control board uses readings from this sensor to determine when defrost is complete and to protect the evaporator from overheating. When the board detects a temperature reading above 150°F or below -58°F, it flags this error because both extremes fall outside the physically possible operating range of a properly functioning sensor in normal conditions.

The error is triggered by one of several electrical or mechanical failures in the sensor circuit. A disconnected connector at the sensor or control board end is a frequent culprit, as is a corroded or loose contact at the connector body. Physical damage to the wiring harness, such as a cut or pinched wire from ice buildup or a service incident, can also interrupt the signal. A short circuit in the wiring will drive the signal voltage to an abnormal level, producing an out-of-range reading. Finally, the sensor itself can fail internally, causing resistance values to drift far outside the expected range.

Diagnosis begins with a physical inspection of the evaporator defrost sensor connector and the associated wiring harness. Technicians should check for corrosion, bent pins, and secure seating at both the sensor and board connections. If wiring checks out, the sensor resistance should be measured and compared against the expected temperature-to-resistance curve for the specific sensor used in the unit. A sensor reading open or shorted will confirm component failure and require replacement.