[s-cars] VAG COM and other electronic diagnostics

JC jc at j2c3.com
Sat Sep 19 06:11:46 PDT 2009

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

> 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

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...


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