Error Code 4
The freezer defrost sensor is failing and defrost cycles may not work
Critical
Stop using immediately - risk of damage or safety issue
Also displayed as: 4
What This Means
Defrost sensor disconnected; Defrost sensor defective; Main PCB defect; Wiring harness damaged
What actually causes this:
The defrost sensor became loose or stopped working
First Thing to Check
Check if you see excessive frost buildup in the freezer — that indicates defrost problems
Parts Involved
How to Fix
- 1
1. Check voltage between Main PCB CN30 pins 1 and 4 should be within 4.5V to 1.0V range
- 2
2. Verify sensor connector is fully seated
- 3
3. Measure resistance of defrost thermistor
- 4
4. Check wiring harness for damage
This Error Applies To
Samsung RF22M9581 Series Refrigerators
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