Audi Workshop Service and Repair Manuals > A4 Mk2 > Heating, ventilation, air conditioning system | Auxiliary heater | Self diagnosis, V.A.G Inspection Service | Reading measured value block | Display groups as of "006”

Display group “126”

Information on convenience data bus system and operating status of convenience data bus system

Display zone

Significance

Explanatory notes

Network management version number

–	Operating level of convenience data bus system

t	Display = e.g. 2.10

Communication matrix version

–	Data level used by dominant control unit for convenience data bus systen (control unit in dash panel insert -J285-)

t	Display = e.g. 1.80

Communication matrix version

–	Data level of auxiliary heater control unit -J364- on which information is transmitted on the convenience data bus system and expected by other control units

t	Display = e.g. 1.84

Note

t	Only genuine Audi auxiliary heaters can be actuated by way of the convenience data bus system and exchange data with the other control units linked to this data bus system.

t	The majority of commercially available auxiliary heaters cannot exchange data via the data bus system. Such auxiliary heaters are not to be connected to the data bus system.

t	These displays are not used at present for service purposes. Pay attention to the correct part number of all control units linked to the convenience data bus system → Parts List and heed the various workshop manuals and guided fault-finding routines for these control units.

Display zone

Significance

Explanatory notes

Operating status of convenience data bus system

t	Display = Two-wire

–	Convenience data bus system in two-wire mode (normal status)

–	Reception of information transmitted on convenience data bus system at both inputs (“Can-Hi” and “Can-Lo”)

t	Display = One-wire

–	Convenience data bus system in one-wire mode (emergency operation)

–	Reception of information transmitted on convenience data bus system at one input only (“Can-Hi” or “Can-Lo”)

t	Data are transmitted on the convenience data bus system via two wires

–	If “One-wire” is displayed, interrogate the fault memory → Chapter and check the convenience data bus system → Chapter

Note

t	In contrast to the drive data bus system, the convenience data bus system can also operate in one-wire mode. However the system is then set to emergency operation.

t	If no information is received on the convenience data bus system, the auxiliary heater control unit -J364- deactivates or does not activate auxiliary heating/auxiliary ventilation.

Audi Workshop Service and Repair Manuals