Error Code 4
Defrost cycle cannot operate properly
Moderate
Address soon - your appliance may not work properly
Also displayed as: 4 (Freezer LED blinks)
What This Means
Freezer defrost thermistor disconnected; Freezer defrost thermistor defective (open or shorted); Bad wiring between defrost sensor and MAIN PCB; MAIN PCB defect
What actually causes this:
Sensor detecting temperature incorrectly or wire is broken
First Thing to Check
Verify the wire is connected to the defrost sensor
Parts Involved
How to Fix
- 1
1. Enter self-diagnostic mode via Engineer Mode (select '3')
- 2
2. Measure voltage at MAIN PCB CN51 pin 5 to pin 7 — normal range: 1.0V to 4.5V
- 3
3. Disconnect CN51 and measure resistance between pins 5 and 7 — compare to temperature table
- 4
4. Check MICOM input at IC01 MICOM pin 3 and resistor R352
- 5
5. If sensor tests normal, replace MAIN PCB
This Error Applies To
Samsung RF22A4 Series Refrigerators (2021) (2021–present)
Related Error Codes
Control panel cannot talk to main circuit board
Main board cannot control the compressor
Freezer is not cold enough
Cannot detect compressor motor position
Inverter board is too hot
Humidity level cannot be monitored
Water in dispenser tank cannot be heated
Compressor protection circuit activated