What does dF mean?
Defrost cycle did not complete successfully. Evaporator coil may be iced over.
Common causes
- Failed defrost heater
- Defrost thermostat open
- Defrost timer/board failure
- Excessive frost buildup
Diagnostic & testing steps
- 1. Check for heavy frost on evaporator coil
- 2. Test defrost heater for continuity: 20-40 ohms
- 3. Test defrost thermostat - should be closed below 40°F
- 4. Check defrost control board or timer for proper cycling
- 5. Manually initiate defrost cycle from diagnostics mode
Tools required
- Multimeter
- Phillips screwdriver
- Hair dryer
OEM parts & part numbers
Defrost Heater, Defrost Thermostat, Defrost Control Board
Part numbers: PB070249, PB070250, 002619-000
Safety warning
⚠️ Do not use sharp objects to remove ice from evaporator - risk of refrigerant leak
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