What Fault 4 Means
Fault 4 is the flip side of Fault 3: the main compartment sensors are showing a resistance below 660 ohms, a short-circuit reading that again tells the control board it's dealing with a sensor or wiring problem rather than an actual temperature swing.
Common Causes of Fault 4
- The temperature sensor has shorted
- Damaged sensor wiring creating a short-circuit condition
- Moisture getting into the sensor connector
🔧 One Safe Check You Can Try
There's no safe way to check this yourself — verifying sensor resistance calls for a multimeter on a completely de-energized unit, technician territory.
⚠ Why You Shouldn't Go Further Than That
- The same wiring bundle that feeds these sensors also feeds the compressor's control circuit, so a misplaced probe while troubleshooting can set off an unrelated fault.
- Replace the sensor on the wrong assumption and the fridge is left running on unreliable temperature readings even longer, which isn't a great place to leave food safety.
- These sensors typically mount near refrigerant tubing, so careless handling while reaching one risks a leak that's far more expensive than the sensor itself.
- A connector that goes back together wrong can leave you with an entirely different, harder-to-diagnose fault next time around.
- Interior panel removal to reach this wiring is generally enough on its own to void what warranty coverage remains.