A/C System, General Repair Guidelines

A/C System, General Repair Guidelines

It is only permissible if so required by the pertinent safety regulations, or if parts of the air conditioner refrigerant circuit have to be replaced, to drain and open the air conditioner refrigerant circuit.

The air conditioner refrigerant circuit must also remain closed during all other normal vehicle repair operations.

Service work which can be performed on the heater and air conditioner without opening the refrigerant circuit is described in this Workshop Manual.

NOTE: The connections for the sensors/switches are installed with a valve which closes automatically when the switches are unscrewed. These switches can therefore be replaced at any VW/Audi workshop without discharging the refrigerant circuit.

Air conditioner servicing work which involves discharging the refrigerant circuit and can therefore not be performed at every VW/Audi workshop.

NOTE:
- With the Audi Cabrio, different settings are stored for closed and open convertible top in the operating and display module, Climatronic Control Module J255. On opening and closing the convertible top, the operating and display module, Climatronic Control Module J255 then automatically alters the setting to the value last set with convertible top closed or open.
- As of April 2002, operating and display modules, Climatronic Control Module J255 with part number index "H" onwards (with hardware/software version as of "XX15") have gradually been installed. With these operating and display modules, Climatronic Control Module J255, the passenger compartment temperature regulation is designed to be somewhat cooler.
- Vehicles as of Model Year 2003 are only to be installed with operating and display modules, Climatronic Control Module J255 with part number index "H" onwards.
- Vehicles with 4-cyl. engine and gasoline direct injection (FSI) are only to be installed with operating and display modules, Climatronic Control Module J255 with part number index "H" onwards.
- As of Model Year 2003, operating and display modules, Climatronic Control Module J255 with part number index "H" onwards (with hardware/software version as of "XX16") have gradually been installed. These operating and display modules, Climatronic Control Module J255 differ as follows from the model with software version "XX15":
- Modified passenger compartment temperature regulation for Audi Cabrio and open convertible top (designed to be somewhat cooler)
- Extended temperature adjustment range; 16 degrees C (instead of 18 degrees C) is now the lowest temperature which can be set.
- Vehicles up to VIN "399999" in Model Year 2005 (Saloon and Avant; gradual introduction for the Cabrio in week 46/04 with no prior specification of any particular VIN) are not to be installed with operating and display modules, Climatronic Control Module J255 with part number index "AJ" onwards.
- Vehicles as of VIN "400000" in Model Year 2005 (Saloon and Avant; gradual introduction for the Cabrio in week 46/04 with no prior specification of any particular VIN) are only to be installed with operating and display modules, Climatronic Control Module J255 with part number index "AJ" onwards.