What does error code FRIDGE_DEF_SENSOR mean on a Samsung refrigerators?

Fridge compartment defrost sensor is faulty or disconnected Connector CN20 pins 5/7 loose; Sensor open or shorted; Wiring damage near REF evaporator

How do I fix error code FRIDGE_DEF_SENSOR on a Samsung refrigerators?

1. undefined: Verify voltage at MAIN PCB CN20 pins 5 and 7 is between 1.0V and 4.5V 2. undefined: Disconnect CN20 and measure resistance at R-DEF: CN20 '5' ↔ '7'

Samsung Refrigerators2023–present

Error Code FRIDGE_DEF_SENSOR

Fridge compartment defrost sensor is faulty or disconnected

Moderate

Address soon - your appliance may not work properly

Also displayed as: R blinks

What This Means

Connector CN20 pins 5/7 loose; Sensor open or shorted; Wiring damage near REF evaporator

What actually causes this:

The defrost sensor in the fresh food compartment has failed or lost connection, potentially causing improper defrost cycling.

First Thing to Check

Confirm the yellow defrost sensor connector on the back of the REF evap cover is firmly seated.

Parts Involved

Thermistor 502AT (R-DEF sensor)MAIN PCB CN20

How to Fix

1
Verify voltage at MAIN PCB CN20 pins 5 and 7 is between 1.0V and 4.5V
2
Disconnect CN20 and measure resistance at R-DEF: CN20 '5' ↔ '7'

This Error Applies To

Samsung RF23BB89 Series Refrigerators (2023) (2023–present)

Service manual exact match: RF29BB89***Service manual exact match: RF24BB66***Service manual exact match: RF30BB62***Service manual exact match: RF29BB82***Service manual exact match: RF30BB69***Service manual exact match: DRF36C300**Service manual exact match: RF24BB69***Service manual exact match: RF30BB66***+2 more