GE Refrigerator Error Code I/M-SENSOR

The I/M-SENSOR code indicates a fault in the ice maker temperature sensor circuit. The main PCB monitors a signal voltage from the ice maker thermistor that should stay between 4.5V and 1.0V. The error triggers when the voltage falls outside that range, when the circuit is open or shorted, or when the sensor reports a temperature above 122°F or below -58°F.

The refrigerator's main cooling compartment will typically continue operating, so food safety is not an immediate concern. However, the ice maker will likely stop producing ice or operate unreliably while this fault is active. It is best to address the error promptly to prevent any secondary issues from developing.

A reset may temporarily clear the code from the display, but it will return quickly if the underlying sensor circuit fault has not been corrected. A power cycle or control board reset does not repair a failed thermistor, broken wire, or damaged connector. The error should be treated as an active fault that requires physical diagnosis rather than a software glitch that a reset will resolve.

Start by checking the voltage at the main PCB sensor connector with the unit powered on, looking for a reading between 4.5V and 1.0V. If voltage is absent or incorrect, inspect the wiring harness and sensor connector for damage or corrosion. A thermistor that tests open or shorted will need to be replaced. If wiring and the sensor check out, the main PCB sensor input circuit may need evaluation.

If the fix is limited to cleaning or reseating a connector, there may be no parts cost at all. Replacing the ice maker thermistor typically involves parts costs in the range of $15 to $60 depending on the model. If a technician is needed for diagnosis and repair, total service costs including labor generally range from $100 to $300, with main PCB replacement representing the higher end of that spectrum.