Audi A6 VIN: Find Chassis Number on CAN Bus

Hello everyone,
I have a question about that.

The VIN (Vehicle Identification Number) in the Audi A6 4G is located at ID 0x6B4.
Die besteht aus 3 Teilen. Okay, gib mir den deutschen Text, den du übersetzt haben möchtest.
00 53 53 2D F5 57 41 55
01 5A 5A 5A 34 47 37 43
02 4E 30 34 39 30 xx xx

First line: ...WAU
Second line: ZZZ4G7C
Third line: N0490xx

What interests me are the data that appear BEFORE 'WAU'.

Does anyone have any idea what '53 53 2D F5' could mean?
How can I decipher or generate them myself?

Very important!

Thank you.
Best regards, Alex.

a4b68e wrote:

Hello everyone, I have a question about that. In the Audi A6 4G, the VIN is located on ID 0x6B4

.

Okay, those strange IDs you Audian people are using always confuse me – are they on the propulsion CAN bus?

Otherwise:

Quote:

Die besteht aus 3 Teilen. Okay, gib mir den deutschen Text, den du übersetzt haben möchtest. 00 53 53 2D F5 57 41 55 01 5A 5A 5A 34 47 37 43 02 4E 30 34 39 30 xx xx First line: ...WAU Second line: ZZZ4G7C Third line: N0490xx What interests me are the data that appear BEFORE "WAU". Does anyone have any idea what "53 53 2D F5" could mean?

You've already correctly identified the multiplex section. If the rest is like in a VW system, then those 4 bytes represent the "vehicle secret," and as the name suggests, I don't know anything else about it.

Best regards,
Ingo

Thank you for the response.
I already suspected that it was the checksums.
Then I wasn't that far off.

I absolutely need to know how those 4 bytes can be generated.
They vary from vehicle to vehicle, but they do not change within the same vehicle.

What would be a possible procedure to decrypt the data?

I bought a combination instrument and I want to get it working on the table.
The vehicle's VIN is known, but that's not enough.
The speedometer is locked due to component protection.


I am grateful for any ideas you may have.

Best regards, Alex.

Hello Alex,
I'm currently working on the same problem as you (A6 4F) and I wanted to ask if you were able to solve it yet? If not, maybe we could try to figure it out together.
Here's what I've found so far: it seems that the key and engine control unit also need to send a VIN/FIN so that the instrument cluster 'believes' it's in the correct vehicle. I can roughly guess the IDs for the key and engine control unit, but I'm missing the FIN for my instrument cluster. Is there a way to find this out? How did you find yours?

My AI has now entered a 'safe mode.' I hope that by sending the correct FIN packet, I can bring it back to normal operation.


Best regards,

Andrej.

This is a bit old, but it might still be interesting...
The first 4 bytes are assigned during the AI's initialization process (related to something like the Write Flash Sector and possibly component protection).
You can't simply read them out or calculate them. Even using a brute-force method like 'Beuteforce' would likely take too long, as there are nearly 4.3 billion possibilities.