[s-cars] VAG COM and other electronic diagnostics

Tom Green trgreen at comcast.net
Sun Sep 20 13:27:54 PDT 2009


The VAG-COM is going to make life a lot easier than the generic reader  
because it records why many
of the DTCs were recorded: open circuit, ground fault, out of  
tolerance rich or lean, etc, as well as the
ability to graph and record outputs while you drive.  If you own a  
laptop PC, that helps reduce the cost,
but the VAG-COM cost is not trivial.

There are a lot fewer modules on the S6 than newer models, and the  
diagnostic capabilities on the newer
models are amazing in some respects.  You should verify that the  
generic OBDII reader will access the
OBDI information on the S6, since commonality of the code was not  
required, and some will not read with
the 2X2 connector.  Many of the FLAPS will read your DTCs free and use  
the same readers they sell, so that
would be a way to check one out.  You may need your own 2X2 adapter  
since they are looking for an OBDII
purple connector.

There are a lot of other areas to use the VAG-COM besides the engine  
faults--even on the S6, i.e., resetting
the inspection lights, ABS faults, airbag fault codes and resets, and  
many more on the newer models.  This
code reading won't fix your car, and in many cases is just a hint of  
where to start, but when coupled with the
Bentley manual for troubleshooting specific DTCs, it sure beats raw  


-----Original Message-----
> Date: Sun, 20 Sep 2009 10:56:02 -0400
> From: Cody Forbes <cody at 5000tq.com>
> Subject: Re: [s-cars] VAG COM and other electronic diagnostics
> To: Manuel Sanchez <manuelsanchez at starpower.net>
> Cc: s-car-list list <s-car-list at audifans.com>
> Message-ID: <D888C513-84B0-4A15-A0FD-6C2B36EEF07B at 5000tq.com>
> Content-Type: text/plain;	charset=us-ascii;	format=flowed;	delsp=yes
> A basic code reader gives you exactly what it says.. a code, ie.
> P0123. From tgat point it is up to you to find out what that code
> means, usually via Google. VAGCom will give you the code, the OBDII
> standard description, and any additional info that VAG adds to the
> OBDII description. See:  http://ross-tech.com/vcds/tour/ 
> dtc_screen.html
> From there you can use the VAG proprietary 'measuring blocks' to view
> data to help pinpoint you problem, ie. watch the cylinder specific
> missfire counters live to pinpoint a bad ignition coil, check temp
> sensor readings, etc. See: http://ross-tech.com/vcds/tour/m- 
> blocks.html
> Play with that online demo in both of those links above to go through
> the software and find all of the features. FWIW VAGCom does also
> function as an avanced OBDII scan tool for all vehicles. In my opinion
> it is loads better than even an expensive generic scan tool. See: http://ross-tech.com/vcds/tour/obd-2.html
> -Cody (mobile)
> On Sep 20, 2009, at 9:47 AM, Manuel Sanchez
> <manuelsanchez at starpower.net> wrote:
>> JC,
>> Thanks for the info.
>> A few follow up question.....
>> So VAGCOM or other manufacturers proprietary interfaces allow you to
>> do many other things than just pull engine OBD codes, but lets say
>> for the moment we compare VAGCOM and a run of the mill code reader
>> that you can but at a FLAPS when you are trying to help diagnose an
>> engine problem, will the VAGCOM be able to offer more information for
>> an engine problem than the simple code reader?
>> TIA,
>> -Manny
>> On Sep 19, 2009, at 9:11 AM, JC wrote:
>>> Manny -
>>>> If you were going to buy some sort of electronic vehicle
>>> VAG-COM no doubt. Think you might be confused about OBD 1/2.  More  
>>> on
>>> that...
>>>> Can VAG COM read items that a run of the mill current
>>>> electronic diagnostic tool can't?
>>> Depends on what you mean by 'read' and 'run of mill'.  Sure a ROTM
>>> little
>>> OBD tool should pull basic engine codes and clear them.
>>> But part of it is in how it is done - generic "OBD" readers don't
>>> do a ton
>>> of stuff in the interface that VAG-COM does. VAG-COM's first big
>>> value add
>>> is in huge databases of descriptions and lookups for codes and
>>> readings and
>>> inputs so you don't have to constantly look up codes or measuring
>>> block
>>> numbers to remember what they mean, you get the description. As
>>> well as a
>>> lot of other cool functionality like graphic display of reading/
>>> monitoring,
>>> ease of changing default settings for central locking modules etc.
>>> Re: HW vs. SW solutions - benefit of dedicated hardware scanners is
>>> usually
>>> that they are small and simple to hook up and you don't have to
>>> wait for a
>>> PC to boot etc. Otherwise a PC solution is usually vastly superior
>>> for
>>> reasons above.
>>>> I ask because I have 2 VAG products;  one is OBD 1 and the
>>>> other OBD 2.
>>>> In an ideal world I would get one device that talks to all of
>>> OBD 1 vs. 2 is hardly the most important distinction... everything
>>> does
>>> OBD-II these days. It's actually additional features/
>>> functionalities that
>>> sit on top or outside of the "OBD" part limit what you can do with
>>> older /
>>> simpler scanners. For isntance if you want to work on VW/Audi
>>> models from
>>> last 10 years and do things like re-code new immobilizer keys, you
>>> need one
>>> that can deal with more advanced hardware bus interfaces and
>>> software that
>>> matches.
>>> Any early or basic OBD scanner will work fine for the official OBD  
>>> II
>>> functions of reading engine codes but very likely won't do any of
>>> that
>>> higher level stuff. All the OEM automakers do their own proprietary
>>> computer
>>> interfaces and extensions. For instance, common stuff you do with a
>>> 'proprietary' scanner is be able to reprogram door and window
>>> locking/opening behaviors, set various defaults and formats for
>>> information
>>> displays in the car like the instrument panel... That kind of stuff
>>> is often
>>> proprietary to mfrs so while a VAG compatible scanner will do a
>>> great job
>>> for your VW-Audi family products, if you want to do it on a Saab or
>>> a Jeep,
>>> you need something totally different compatible with their dealer
>>> stuff.
>>> Example: I rented a Volvo this summer with the interface language
>>> set to
>>> German and it was completely annoying that to change it, I would
>>> have had to
>>> have had a proprietary Ford/Volvo tool to change the system.  This
>>> is all
>>> WAY past "OBD" compatiblity specs, which is really just the most
>>> basic
>>> government driven functionality for emmisions control purposes.
>>> So while VAG-COM and other VAG type tools talk to all of them for
>>> VW-Audi
>>> brands (Skoda etc.) However, if what your trying to say is having a
>>> one-stop
>>> scanner for VW/GM/BMW/etc... AFAIK there isn't a great 'super
>>> scanner'
>>> product that does all the things you might want to do for all those
>>> brands... others please invited to correct but I've not heard of
>>> it...
>>> JC

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