What does error code FREEZER-DEF-SENSOR mean on a Samsung refrigerators?

Freezer defrost sensor is faulty and cannot detect when defrost is complete Open or short in defrost sensor circuit; Bad connector at CN20 pins 6 and 8; Failed THERMISTOR (DKST1329)

How do I fix error code FREEZER-DEF-SENSOR on a Samsung refrigerators?

1. undefined: Measure voltage at MAIN PCB CN20-'6' '8': should be between 1.0V and 4.5V 2. undefined: Disconnect CN20 and measure resistance between CN20-'6' ↔ '8' 3. undefined: Compare measured resistance to temperature table (e.g., 13.29kΩ at 32°F/0°C) 4. undefined: Check R223 (IC01 MICOM #6) soldering on PCB

Samsung Refrigerators2022–present

Error Code FREEZER-DEF-SENSOR

Freezer defrost sensor is faulty and cannot detect when defrost is complete

Moderate

Address soon - your appliance may not work properly

Also displayed as: F and R blink together

What This Means

Open or short in defrost sensor circuit; Bad connector at CN20 pins 6 and 8; Failed THERMISTOR (DKST1329)

What actually causes this:

The sensor that ends the defrost cycle when the evaporator is thawed has failed, risking the heater staying on too long or defrost never completing.

First Thing to Check

Reseat the defrost sensor connector inside the freezer evaporator cover.

Parts Involved

Defrost thermistor DKST1329MAIN PCB connector CN20 pins 6-8Resistor R223

How to Fix

1
Measure voltage at MAIN PCB CN20-'6' <-> '8': should be between 1.0V and 4.5V
2
Disconnect CN20 and measure resistance between CN20-'6' ↔ '8'
3
Compare measured resistance to temperature table (e.g., 13.29kΩ at 32°F/0°C)
4
Check R223 (IC01 MICOM #6) soldering on PCB

This Error Applies To

Samsung RF25C5 Series Refrigerators (2022) (2022–present)

Service manual exact match: RF25C5151SR/AAService manual exact match: RF25C5151**Service manual exact match: RF25C5551**Service manual exact match: RF25C5551SR/AA