Audi Workshop Service and Repair Manuals > A4 Mk2 > Heating, ventilation, air conditioning system | Auxiliary heater | Self diagnosis, V.A.G Inspection Service | Checking convenience data bus system | Checking convenience data bus system | Fault(s) in convenience data bus system only displayed by auxiliary heater control unit J364

Fault(s) in convenience data bus system only displayed by auxiliary heater control unitJ364

Fault(s) in convenience data bus system only displayed by auxiliary heater control unit -J364-

–	Prior to further fault-finding, check encoding and adaption (adaption channels “18” and “61”) of control unit in dash panel insert -J285-.

–	Check the signal wires to the auxiliary heater control unit -J364- for open circuit or wiring resistance. Wiring resistance: max. 1.5 ohms → Current flow diagrams, Electrical fault finding and Fitting locations

Note

Pay particular attention to the possibility of loose contacts in the wires and connectors.

If no fault can be found, the problem is in the auxiliary heater control unit -J364-.