Samsung Refrigerators2013–present

Error Code 4E

Freezer defrost sensor is failed or disconnected

Critical

Stop using immediately - risk of damage or safety issue

Also displayed as: 4E

What This Means

Defrost sensor connector slipped out; Open or short circuit in sensor wire; Defective thermistor; Temperature reading out of expected range

What actually causes this:

The defrost sensor near the freezer evaporator can fail from repeated heating and cooling cycles, or its connector loosens.

First Thing to Check

Disconnect power, remove the freezer evaporator cover, and inspect the defrost sensor connector for secure seating.

Parts Involved

Freezer defrost thermistor (DTN-C502)Temperature fuseBimetal thermostat (BT-121-M)Main PCBCN30 connector

How to Fix

  1. 1

    Check voltage between Main PCB CN30 pins 1 and 4 — should be 4.5V to 1.0V

  2. 2

    Measure resistance between CN30 pins 4 and 7 for F-DEF sensor verification

  3. 3

    Perform forced defrost (Lock key + F Compartment Key for 6 seconds) to verify heater operation

  4. 4

    Check if defrost voltage is 3.1V or higher on sensor

This Error Applies To

Samsung RF32FM Series Refrigerators (2013) (2013–present)

Service manual exact match: RF32FM**Service manual exact match: RF32FMQDBSR/AA

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