What the control board is reporting, and which models and series this code applies to. Diagnosis on Miele appliances uses factory service software and procedures.
Freezer section air temperature sensor (R30-3) fault
Models: KFMC 3846 FD
Freezer air NTC has short- or open-circuited
Models: F 2411 Vi, F 2412 Vi, F 2812 Vi
A fault code identifies what the control detected, not which part failed. A sensor error can be the sensor, the harness, the connector, or the board reading it. ServiceON is a factory-authorized Miele service provider.