LG Refrigerator Error Code I/M-SENSOR

The I/M-SENSOR code means the refrigerator has detected a fault in the ice maker temperature sensor circuit. The error appears when the sensor reports a temperature outside the range of -58°F to 122°F, which the control board interprets as a wiring, connection, or sensor failure rather than a real temperature reading. Common causes include a broken wire, a short circuit, a loose connector, or a missing sensor housing. Ice production will stop while this code is active.

Yes, the refrigerator and freezer compartments should continue to cool normally while this code is active because the ice maker sensor circuit is separate from the main cooling system. The primary impact is that ice production will be suspended. You can continue using the appliance for food storage, but the issue should be diagnosed and repaired to restore ice maker function.

Repair costs vary depending on the root cause. If the fix is simply reseating a connector, there may be no parts cost, though a service call fee typically runs between $75 and $150. Replacing the ice maker temperature sensor usually costs between $20 and $60 for the part, plus labor. If the wiring harness needs replacement, total costs including labor can range from $100 to $250 or more. Main PCB replacement, if needed, is the most expensive outcome and can run from $200 to $400 or higher.

Some causes of this error are DIY-friendly. Start by inspecting the wiring harness connected to the ice maker sensor and checking the connector at Main PCB CN 90 pins 3 and 4 for corrosion or loose fit. If you have a multimeter, you can test for voltage between those pins: a reading between 1.0V and 4.5V indicates the circuit is intact. Replacing a sensor or wiring harness is within reach for experienced DIYers, but working near the main PCB carries some risk, and a certified technician should be consulted if you are unsure.

A power reset may temporarily clear the error code from the display, but if the underlying fault in the sensor circuit is still present, the code will return once the refrigerator resumes normal operation and re-checks the sensor. A reset is useful for confirming whether the fault is intermittent, but it is not a repair. The wiring, connectors, and sensor need to be inspected and tested to resolve the error permanently.