Steering wheel phone buttons re-revisted (long, rambling)
 

(If you're not conversant with VWTool, VagCom, or the Audi scan tools, much of the terminology used may be garbledy gook...sorry.)

Ok, here's the status as I know it:
-Early '00 A6s with "multifunction steering wheel" have "&LT" and "&GT" buttons which cycle through radio presets or CD changer disks. (I'll call these "Type A" wheels.)
-Later '00 and '01 A6s with "multifunction steering wheel" have "R/T" and "Handset icon" buttons instead which perform no function in cars without the Audi phone. (I'll call these "Type B" wheels.)

Many people with Type B wheels and no phone (most) would like their Type B wheel to act like a Type A wheel.


Is this possible? More importantly, can it be done by the scan-tool equipped owner?


We know that the Type B wheel can be soft-coded for presence or absence of the phone - as many phone owners have had their wheel coded wrong and STILL had "dead" buttons.

We know that (despite a bug in early VagCom releases which lead me, among others, to believe contrarily) the Type A wheel has NO soft-coding.

We know that the 6 wheel buttons show up in a cluster of 4 (all but the ones that change from A to B) in one of the Type A wheel's data blocks, and the 2 disputed ones in the next data block. (Can't recall them right off hand, but they're low, maybe 2-3?)

It seems almost certain that the radio communicates with other car systems via CAN bus. (See various pics of top of Symphony head unit.)

We know that people replace their radios all the time with aftermarket head units and the cars don't lose all CAN communication.

We know that the radio communicates with the instrument cluster in order to display radio and CD information.

We know that the Type B wheel communicates with the instrument cluster in order to display name/number information from the Audi phone.

IIRC, at least one Audiworld poster claimed he got a Type A wheel replaced with a Type B wheel, and retained his Type A functionality.

So what, Richard, get to the point or shut up...

How's this for a hypothesis:
-We've been looking in the wrong place. The INSTRUMENT CLUSTER is what controls the radio's response to the steering wheel controls.

Some supporting points:
-Suppose the radio CAN bus goes ONLY to the instrument cluser: thus the rest of the car doesn't notice or care when that bus is dangled by aftermarket radio installs.
-Suppose the steering wheel communicates with the instrument cluster via private bus (CAN or otherwise): thus the Type B replacing Type A wheels don't change the cluster to radio communication which is where the preset change commands are actually sent.


Anyone with a Type B wheel willing to go through their instrument cluster and record all the information for comparison with my Type A wheel cluster?

Ask Jim DeArras on the S4 board..
 

He claims to have the "info-CAN" (which is what you're talking about, it is seperate from the powertrain CAN!) pretty well "hacked".

I have hacked a lot of what I can see, I do not have this steering wheel option, so I do not know
 

what events it generates. Also, the A6 has a more "mature" CAN network, the S4, current model, is very much a work-in-progress. The Radio in the S4 communicates with the instrument cluster via CAN (info) AND a deticated serial link.

That said, Richard is right in that the Instrument cluster would be responsible for "decoding" the button presses, and sending the info, probably via CAN, to the radio or telephone. The Instrument cluster indeed appears to function as a bridge between all three CAN busses, (info, drivetrain, windows) allowing queries from one "domain" to another.

To change the button function in software would require programming the instrument cluster. It may be in the logon block, or the coding one (whatever it's called!) If not, changing it will be difficult. The info, if on CAN, is sent to everything on that bus, but the "packet" ID will determine who listens to it.

I'd like to hack an A6 CAN one of these days!

Re: Steering wheel phone buttons (more info)
 

A friend at Audi gave me some information, but not the complete solution.

The US Multifunction steering wheel does not use the CAN bus, but relies on an Audi proprietary 3wire bus between ECU and instrument cluster.

Change Airbag Unit from 6-key "radio/phone" design to 6-key "radio" design.

I tried some soft coding with an older version of the VAG-COM tool back in November, but could not change any of the values and I did not know what the correct value was to set. We need someone to get codes off of the radio design wheel, so we can give it another try.

NeilM

And we thought you were the master hacker!
 

How you doing Uwe?

I haven't done anything with CAN because..
 

The interface hardware for PC's is too expensive to make a mass-market product out of it just yet. Pure hacking for the fun of it is great, if you can afford the time, and I can't, I'm too busy trying to make a living!

Old steering wheel doesn't have soft coding
 

As further evidence that it's not the steering wheel coding someone reported here last year (https://forums.audiworld.com/a6/msgs/24076.phtml) that they had a damaged old steering wheel replaced by a dealer with a new steering wheel and the bottom buttons continued to cycle through the radio presets.

I've tried changing the soft coding for the radio itself, based on a different posting that the radio could be told to change the function of the seek buttons to change presets (https://forums.audiworld.com/a6/msgs/35046.phtml), but that didn't work either.

Presumably someone with the old steering wheel will post their instrument cluster soft coding soon and we'll all rush out to see if that's it.

marcos

Re: I have hacked a lot of what I can see, I do not have this steering wheel option, so I do not kno
 

<i>The Instrument cluster indeed appears to function as a bridge between all three CAN busses, (info, drivetrain, windows) allowing queries from one "domain" to another.</i>

Great! That's what I hoped to hear...at least it means my hypothesis isn't immediately shutdown :)

<i>To change the button function in software would require programming the instrument cluster. It may be in the logon block, or the coding one (whatever it's called!) If not, changing it will be difficult. </i>

Agreed. I suppose it could be an adaptation channel also - I only recently started looking at those as possible sources of configuration.

My hope is that the difference is not firmware/hardware in the cluster but that it's a configurable option....time will tell.

<i>I'd like to hack an A6 CAN one of these days!</i>

Long ago I sent you e-mail about contributing to your instrument cluster boost gauge project. I'm still interested, if you'd like to drop me an e-mail. I imagine we could locate a Virginia A6'er willing to let you snoop their busses if that would be better.

We poor A6 stepchildren are STILL awaiting the Bentley CD, so have not even that smidgen of information :(

Can you pull all the information from your cluster?
 

IIRC, marcos, you have the Type B wheel?

Please pull all the info from the first VagCom screen (part #, soft coding, etc...) for your instrument cluster. It may also be worthwhile to go through and record the adaptation values and/or data blocks.

I will do the same for my Type A instrument cluster and we can compare.

Re: Old steering wheel doesn't have soft coding
 

I'm interested in this and may be able to help. I have a VAG-COM and a 2001 2.7T with the phone buttons on the wheel. I also have found a guy at work who has a 2000 2.7T with the earlier steering wheel that has the lower p-scan radio buttons. He is willing to let me hook up VAG-COM to read out code numbers. At the moment, his wife has that car and we need to arrange to get together sometime over the next few days.

As I am a VAG-COM beginner, any pointers as to what numbers to record would be appreciated. I assume for now that I need to look at the main entry screen for the Instrument Cluster and also record the numbers on the Adaptation channels below that screen. I will look at and record this stuff off my car so that I can have the numbers to contrast with what I get off my friend's car.

Stay tuned.

- Tom