Samsung Refrigerator Error Code I/M-SENSOR (R)

The I/M-SENSOR (R) code indicates an error with the ice maker temperature sensor on the refrigerator side of a Twin Ice Maker unit. The control board has detected either an open circuit, a short circuit, a connector problem, or a temperature reading outside the valid range of -58°F to 122°F. The first diagnostic step is checking the voltage at the MAIN PCB sensor connector, which should read between 1.0V and 4.5V under normal conditions.

A power reset may temporarily clear the error code from the display, but the code will return if the underlying fault is still present. Because the code is triggered by a measurable electrical condition, such as voltage outside the 1.0V to 4.5V window, the issue must be physically corrected before the error will stay cleared.

If only the sensor thermistor needs replacement, parts costs typically range from around $15 to $60 depending on the specific model, with professional labor adding $80 to $200 or more. A connector or wiring repair may fall at the lower end of that labor range. MAIN PCB replacement is the most expensive outcome, with parts alone often ranging from $100 to $350 or higher for this repair.

Some causes are DIY-friendly, particularly inspecting and reseating the sensor connector, which requires no special tools and no parts. If the connector is secure and the wiring is intact, testing the sensor thermistor and replacing it is a moderate-difficulty repair that requires sourcing the correct replacement part. MAIN PCB replacement is more complex and typically better suited to a technician.

The refrigerator's main cooling function is typically separate from the ice maker sensor circuit, so food storage is generally not immediately at risk. However, the ice maker on the fridge side will likely not operate correctly while the fault is active. It is best to address the error promptly to prevent any secondary issues from developing.