Refrigerant Temperature Sensor -G454-
The refrigerant temperature sensor (with temperature-dependent resistance) is installed in the high pressure line near the A/C compressor, for example (only for certain vehicles that were built within a certain time frame, for example Audi Q7 from MY 2007).
In the refrigerant circuit, there is a direct correlation between temperature and pressure. Should there be too little refrigerant in the refrigerant circuit, the temperature in the refrigerant circuit rises more strongly than intended for this pressure when A/C system is operating.
Switch pressures, removing and installing switches as well as switch arrangement and version. Refer to vehicle specific refrigerant circuit Air Conditioning (1 Of 3) / Air Conditioning (3 Of 3) (vehicle-specific Service Information).
Installed for example on the Audi Q7 with specific engines. Refer to Air Conditioning (1 Of 3) / Air Conditioning (3 Of 3) (vehicle-specific Service Information) and the appropriate Wiring Diagram.
The Climatronic Control Module -J255- evaluates pressure and temperature in the refrigerant circuit and switches off the compressor in the event the temperature increases above the value stored for this pressure. Refer to Air Conditioning (1 Of 3) / Air Conditioning (3 Of 3) (vehicle-specific Service Information) and Vehicle Diagnostic Tester ("OBD" or "Guided Fault Finding for the A/C system").