Frigidaire has one of the more useful code sets in the mainstream market, and the refrigerator codes in particular name the circuit outright — SY EF says the evaporator fan, and that is a diagnosis rather than a hint. The oven control codes are equally direct and matter more than most, because they separate a cheap membrane from an expensive control board before anything is ordered. The same set applies to Electrolux, which shares the platform.
Codes are not standardised between manufacturers, and they move between model years within one. Everything below is what these codes mean on the series named beside them — if your model is older or newer, treat this as a strong hint rather than a verdict, and send us a photo of the model plate when you book. That plate settles it, and it takes ten seconds.
Refrigerators alternate the code with the temperature on the front display. Ovens show it on the clock. On laundry, the code appears where the cycle time sits, and on some models only after the door is opened and closed once.