What does IC 20 mean?
Freezer evaporator temperature sensor is reading out of range.
Common causes
- Failed thermistor
- Loose connection
- Wire harness damage
- Frost covering sensor
Diagnostic & testing steps
- 1. Access freezer evaporator cover
- 2. Locate thermistor on evaporator coil
- 3. Check for ice encasing sensor
- 4. Measure resistance: ~15K-20K ohms at 0°F
- 5. Check wiring back to main control board
Tools required
- Multimeter
- Phillips screwdriver
- Torx screwdriver
OEM parts & part numbers
Freezer Evaporator Sensor
Part numbers: 4204390, 4204391
Safety warning
⚠️ Unplug before accessing evaporator
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