K-Line and CAN-Bus a brief summary and simple overview:
Your A4/B6 does all it's diagnostic through the OBD-II diagnostic port. The connection from this point to all the individual modules in your car uses what we call "K-Line", a single wire, (with the obligatory earth 0v signal) which carries all the diagnostic commands to/from VAG-COM/VCDS. The speed of the data transfer is not particularly fast but fine for the diagnostic signals to and from units.
Between certain units in the car there is communication to pass on various information, a particular part of this is called the "Infotainment CAN-Bus" and this uses CANBus-L, CANBus-H and the obligatory 0v ground signal. For example, your OEM Radio sends CANBus signals to and from the the Instrument cluster to display the Radio channel info etc. If you have an OEM BT module all the data transfer, like Directory download, missed calls numbers, Pick-up handset, Drop call and so on are passed over the CAN-Bus lines. If you have a TV tuner, channel select is done over CAN-Bus to the unit in the boot, etc. CAN-Bus can support a small number of devices all on the same "data-bus", but cant support all the car units at the same time.
Newer Audi car models have a CAN-Gateway module, it's like a Network switch as you have on a computer Ethernet network at home or in the office. All modules plug into this central CAN-Gateway and can all communicate with each other as required. We plug in our VAG-COM/VCDS cable and we talk using the CAN-Bus connection method and not the K-line method to any of the addressed units.
What about a OEM BT module - how to connect?
If your purchased OEM BT module and it is from an A4/B6 where they are using K-line and you fit it in your car and connect all the wires up correctly you should have no problem recoding it to your specific specification requirements with VCDS/VAG-COM.
If you purchased an OEM BT module from a car where it was configured for diagnostics via CAN-Bus then you will not be able to do anything with this unit in your car. Why? The unit is expecting to receive diagnostic signals via CAN-Bus and not K-line so will sit there waiting for diagnostic CAN-Bus commands. The only way to get around this (as far as we know), is to put the BT unit in a newer model car using CAN-Bus and CAN Gateway and then reprogramme the unit coding from 0???? to 1????. Similarly, this unit will then not respond to CANBus diagnostic codes as is waiting for K-line diagnostic codes.
I would say you best bet is to ask for the Polish seller to pre-configure your BT unit to Coding value "0010702", which is as follows:
0=not used
0=not used
1=D3/C6 High Specification****
0=non multifunction steering wheel
7=HU and K-line
0=voice control off
2=English (UK) DIS info
item marked **** is the key to this and you
DO NOT want, 0=with CAN-bus (A2/A3/TT).
You can change the 0702 part yourself then as required to suit your spec.
RNS-E Firmware Reload:
I have seen this Software X--- on a fellow forum members RNS-E and he advised he had used a PIN hack firmware CD to unlock his RNS-E. There may be other instances where this "X" version pops up, but this is one I know of.
Normally you will lose all your system settings but you can get all these dumped into a file using VCDS/VAG-COM. You will have to manually put in each value individually again - but not a major problem.
How to capture all that channel information, from another forum thread I have the following on file, (so can't take the credit for this):
To capture the adaptation channel values I used VAG-COM 704.0. Under Applications / Controller Channels Map select Controller Access 37, Function Adapation, Output CSV file. It creates a file adpmap-37-8E0-035-192-E.CSV at \Ross-Tech\VAG-COM\Logs\, rename this before doing the second scan or it will get overwritten. Do this before you start the update and after finishing all updates and compare the two exports, this way it's very easy to see which channels changed.
