LIN bus

Hey everyone,

"I need to install a 9N3 (year 2009!) base system, including electric folding mirrors, electric side mirrors, central locking with remote control, etc. In this model, the door control units do not communicate via the CAN bus like in the 9N, but instead use the LIN bus."

Everything seems fine so far, and I've also created the wiring harness according to the wiring diagram. However, I'm not sure where I can tap into the LIN bus! On the circuit diagram, only the connection to the main bus bar and the LIN bus (B 528)) is indicated.

I believe the LIN bus is connected to the body control module, as the windshield wipers are supposedly also controlled via the LIN bus.

Does anyone know anything about that? A pinout diagram would be great!

Regards,
Thomas.

Consider that you might need to access the vehicle's body control module or the CAN gateway. But are you sure about using the LIN bus for the comfort systems? I can't really imagine it.

I'm sure because it's the same with the 9N3, and it's also evident from the circuit diagram.

The control unit on the driver's side is the master, while the one on the passenger's side is the slave.
Supposedly, all you need to do is connect the two door control units.

Pimpowski wrote:

Supposedly, all you need to do is connect the two door control units to each other...

Possible, but then the door control units wouldn't receive any information about what's happening elsewhere in the car. Or do they have separate signal lines for things like speed, a crash signal from the airbag control unit, etc.?

Actually, no... the entire comfort system is controlled via the CAN bus, only the window lifters use the LIN bus (this only applies to the 9N3 model). I don't know what information the LIN bus transmits or what information it requires.

"Only" from all my circuit diagrams does it become clear how to wire the LIN bus to the door control units and up to the A-pillars. Afterwards, it needs to be connected to the main power line B 528. Perhaps they are only connecting the individual door control units to each other (for some reason).

Hello,

In the current Audi B8 platform (A4, A5, Q5), only the front traction control unit (TSG) communicates with the rear TSG via the LIN bus. The two front TSGs are connected to the CAN bus and only exchange information with the respective rear TSG via LIN.
The LIN bus is not a true bus system where many control units are connected and exchange data, as is the case with CAN. Most often, only two electronic control units (ECUs) exchange data via the LIN (Local Interconnect Network) bus.

I suspect the situation is similar at Volkswagen.

This is because the LIN, as the name suggests, is essentially a simple bus system. (It uses a single wire, while CAN uses two wires, but even if one wire fails, CAN can still function – a key aspect of its safety features.)
In our systems, instrument clusters often communicate internally using the LIN protocol.

Okay, I managed to do it!

The LIN bus is only connected to the door control units in the 9N3 and is not connected anywhere else.

Greetings.