I am looking for info on the A4’s CAN network (specifically a 2008 A4 B7 - although anything would be useful).

I want to add my own CAN module to the Convenience/Comfort CAN bus (have seen references to both and they look like the same thing) and although I have the service manual it doesn’t contain anything like a full wiring diagram. I want to place it under the rear shelf and am looking for spare CAN connection close to there. My prime candidates are the Tow hitch, Rear memory seats, Roof connections (as I am hoping at least one of these are connections to modules that are not fitted/in use) although am open to any other suggestions.

Reason: My ‘new’ car (2008 A4) doesn’t have the Homelink system and I would like to add my own. I placed a Raspberry Pi in my boot and confirmed that it was still linked to my home’s WIFI system and want to use a WIFI link into my Home Automation system (will probably use a STM Discovery (+ Zentri/ACKme) modules as that doesn’t have to boot Linux every time it starts up).
E.G. If the system starts up and can connect to the WIFI – I’m leaving – Put the house into sleep mode.
If the system detects the WIFI after running for a while – I have come home – Switch on the exterior/hallway lights (if it’s dark) and the heating system (if it isn’t already).

I am happy to make the project publicly available if anyone else is interested.

The best info I have found so far is this Audi CAN training info:


Yes, I understand that hacking into the cars CAN network is risky. But as my job involves creating new CAN/RDM products, I am think I am prepared to take the risk.