Samsung Refrigerator Error 40E — Ice Maker

What Does This Error Mean?

Error 40E means the ice maker room thermistor (temperature sensor) has failed. The ice maker cannot measure its own temperature and shuts down. A power reset or sensor replacement resolves the fault.

How to Fix It

Unplug the fridge for 10 minutes, then reconnect and allow the ice maker to complete a self-test. 40E sometimes appears after a power interruption and clears on its own.
If 40E persists, remove the ice maker assembly from the freezer. It is typically held by 2-3 screws and a wiring harness connector.
Locate the small ice maker room thermistor — it is clipped to the ice maker housing. Inspect the wiring for damage and the connector for corrosion.
Test the thermistor with a multimeter. At freezer temperatures (-18 degrees C) it should read approximately 30,000-40,000 ohms. An out-of-range reading confirms it has failed.
Replace the thermistor or the full ice maker assembly (the sensor is often sold as part of an ice maker kit). Refit and reconnect, then allow 24 hours for ice production to resume.

Frequently Asked Questions

Is 40E the same as 40C on Samsung fridges?

Yes. 40E and 40C are the same ice maker thermistor fault. The letter varies by model and region.

Can 40E appear without the ice maker stopping completely?

Yes. In some modes the ice maker continues to operate in a limited way while reporting 40E. However, ice quality or output may be reduced.

My Samsung fridge keeps showing 40E after replacing the thermistor — why?

If the new sensor still triggers 40E, check the wiring harness from the ice maker to the main control board for damage or a loose connector pin. A faulty control board is less common but possible.