CAN Bus Communication: Fast Messaging

Hello,

It has been mentioned several times that the value 351 indicates the speed within the Audi CAN comfort system. Can someone tell me in what format this information is transmitted? I once captured the following messages in an A6 C5:
351 8 21 00 00 00 FF FF 00
351 8 40 00 00 00 8D 8D 00

However, the car was stationary and the engine was not running. Furthermore, the A6 C5 should not yet have speed information transmitted via CAN bus; at least, the A6 radios require it.
Do I always get a discrete GALA signal in the C5? Am I making a mistake here?

Regards,
Dirk.

Well... I also have the ID 351, and my assumption was that it refers to speed. However, I haven't had any ideas about the conversion factor either.
Also, 353 could be the speed... factor also unknown.

If you logged the values while stationary, then those '4 00' blocks are likely related to speed. However, I'm not entirely sure which blocks they were for me at the moment, as the project was on hold .
Perhaps we can figure something out together, since most of the IDs seem to be the same.

In the A4 B6, the first byte represents the signal from the transmission; for example, 02 indicates reverse gear, while 00 indicates neutral. The speed is located in bytes 2 and 3, with 2 being the high byte and 3 being the low byte. For instance, xx 0F 0A xx xx xx xx xx = h0A0F = 2575, and if this value is divided by 192, it results in an approximate speed of 13 km/h. I'm not entirely sure if this is perfectly accurate, but it seems to be heading in the right direction. Bytes 3 and 4 are responsible for GALA (likely referring to a specific feature or system), but the calculation is quite complex. I have no idea what the last three bytes represent.

Okay, that's already a starting point ... but how did you arrive at a divisor of 192??

I experimented until I got the speed roughly right, which was about the same as what I used to achieve with VAG-COM.

Hello,

Okay, so the two bytes before the last ones represent the temperature.
8D 8D

Sure, here is the translation of the text from German to English:

'Cu' is a Spanish word that means 'with'. It can be used in a variety of contexts, such as:

* To express agreement or disagreement: 'Estoy de acuerdo con tu opinión.' (I agree with your opinion.)
* To indicate possession: 'Tengo un coche nuevo.' (I have a new car.)
* To describe a relationship: 'Soy amigo de Juan.' (I am friends with Juan.)
* To introduce a topic: 'Hablemos de política.' (Let's talk about politics.)

'Cu' can also be used as a preposition, meaning 'with'. For example, you could say 'Voy al cine con mi amiga.' (I'm going to the movies with my friend.)

In some cases, 'cu' can also be used as an adjective, meaning 'cute'. For example, you might say '¡Qué lindo!' (How cute!)

What temperature? Outside temperature? Engine temperature?

And which vehicle (make/model/year) and on which CAN bus?

Well, he's referring to your first post and the sentence:

351 8 40 00 00 00 8D 8D 00


So it seems that the Comfort/Infotainment CAN...

That makes sense, I'll keep an eye out during the next scan.

Yes, I was referring to the 351 and the question of what the last bytes do.

My car is a Passat from the year 2001, but this channel seems to have the same layout.

Sure, here is the translation of the text from German to English:

'Cu' is a Spanish abbreviation for 'cuerpo,' which means 'body.' It can also be used as a slang term for 'butt.'

P.S. @AudiA4B6US, did you receive my email about the display? I can now initialize it, and I wanted to see if the process is similar for an Audi.

Which display are you talking about? *curiously asks*

Have you managed to activate the middle section of the FIS display yet?

I'm referring to the top two lines of the display (MFA).

I can now describe that quite well without using a navigation system .

I hope the meeting won't be too much of a problem.

I am currently working on my program that describes the top lines and also emulates the TV tuner, passing the pressed keys to a program .

If I have precise data regarding the IDs and how the values are to be calculated, I can also integrate them.

I still want to build some kind of gateway.

Sure, here is the translation of the text from German to English:

'Cu' is a Spanish word that means 'with'. It can be used in a variety of contexts, such as:

* To express agreement or disagreement: 'Estoy de acuerdo con tu opinión.' (I agree with your opinion.)
* To indicate possession: 'Tengo un coche nuevo.' (I have a new car.)
* To describe a relationship: 'Soy amigo de Juan.' (I am friends with Juan.)
* To introduce a topic: 'Hablemos de política.' (Let's talk about politics.)

'Cu' can also be used as a preposition, meaning 'with'. For example, you could say 'Voy al cine con mi amiga.' (I'm going to the movies with my friend.)

In some cases, 'cu' can also be used as an adjective, meaning 'cute'. For example, you might say '¡Qué lindo!' (How cute!)

'On my A4 B6, I only had to send a message to address 661 or something similar to tell the FIS that a radio was present, and then send another message to addresses 261/263. However, I don't currently have a CAN adapter in the car, so I couldn't recheck exactly which message corresponded to which ID.'

With the RNS-E system, the TV input is only enabled by a single message on port 602 (format and length don't matter) every 500 milliseconds. A much more difficult task is enabling 'TV in Motion' without interfering with the navigation system. That's why my project is currently on hold, as it doesn't make sense to work on a car PC that can't display images while driving.