Audi Workshop Service and Repair Manuals > A4 Mk2 > Heating, ventilation, air conditioning system | Air conditioning | Self diagnosis, V.A.G Inspection Service | Checking convenience data bus system | Checking convenience data bus system | Identification of faults in convenience data bus system

Convenience data bus system fault(s) only displayed by operating and display unit, Climatronic control unit J255 > < Localisation of possible cause of trouble

Identification of faults in convenience data bus system

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With the ignition switched off, connect up the vehicle diagnostic, testing and information system -VAS 5051A- for example with the diagnostic wire -VAS 5051/5A- and the K-wire adapter -VAS 6017B- or, on vehicles up to chassis number “399999” in Model Year 2005 (Saloon and Avant) and “012913” in Model Year 2005 (Cabrio) → Parts catalogue, the K-wire adapter -VAS 6017A- to the 16-pin diagnostic socket in the vehicle → Chapter.

–	Switch on ignition.

–	Select function “00 - Interrogating fault memory - Entire system”.

Indicated on display of vehicle diagnostic, testing and information system -VAS 5051A-:

All address words stored in the vehicle diagnostic, testing and information system -VAS 5051A- are now consecutively transmitted to the vehicle via the signal wire.

Indicated on display of vehicle diagnostic, testing and information system -VAS 5051A-:

t	Display zone -1- indicates the address word currently being transmitted by the vehicle diagnostic, testing and information system -VAS 5051A-.

t	Display zone -2- shows which control units have responded. The number and type of faults stored in this control unit are also displayed.

–	Wait until display zone -1- indicates “Function completed”.

Note

t	If a different or an additional fault has been stored in a control unit with which the other control units cannot exchange data, rectify this fault before checking the data bus wire system.

t	In the event of a fault in a control unit, there may be problems with the exchange of data with the other control units although this fault does not directly affect the data bus system.

t	Check the part number and the corresponding index of the control unit with which there is no communication. → Parts List

Heating, ventilation, air conditioning system
Air conditioning / Self diagnosis, V.A.G Inspection Service
Checking convenience data bus system / ecking_convenience_data_bus_system/">Checking convenience data bus system
Identification of faults in convenience data bus system

Convenience data bus system fault(s) only displayed by operating and display unit, Climatronic control unit J255 > < Localisation of possible cause of trouble

Audi Workshop Service and Repair Manuals

A4 Mk2

Heating, ventilation, air conditioning system Air conditioning / Self diagnosis, V.A.G Inspection Service Checking convenience data bus system / ecking_convenience_data_bus_system/">Checking convenience data bus system Identification of faults in convenience data bus system

Heating, ventilation, air conditioning system Air conditioning / Self diagnosis, V.A.G Inspection Service Checking convenience data bus system / ecking_convenience_data_bus_system/">Checking convenience data bus system Identification of faults in convenience data bus system

Heating, ventilation, air conditioning system
Air conditioning / Self diagnosis, V.A.G Inspection Service
Checking convenience data bus system / ecking_convenience_data_bus_system/">Checking convenience data bus system
Identification of faults in convenience data bus system

Heating, ventilation, air conditioning system
Air conditioning / Self diagnosis, V.A.G Inspection Service
Checking convenience data bus system / ecking_convenience_data_bus_system/">Checking convenience data bus system
Identification of faults in convenience data bus system