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.
Temperature sensor - Refrigerant (R30-33) open circuit
Models: TWF 640, TWF 720, TWF 760, TWF 780, TCF 620, TCF 630, TCF 640, TDB 130, TDB 230
Refrigerant temperature sensor (R30-33) open-circuited
Models: TXR 960, TWL 780
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.