05CrewCab

2002 A6 2.7T I have the check engine, ABS, and BRAKE lights illuminated on the dash.

I think I have the right driver for the interface and the port set correctly, and VCDS-Lite approves the port, but I can't seem to connect to the car at all. Every module I try attempts several times and fails due to communication errors. The computer is running Windows 7. Is there a trick to getting it to communicate?

On a side note, I tried first to check codes with the rental OBDII scanner at O'Reillys and that wouldn't communicate either...

Any help you can provide will be more than helpful. thanks!

georgeb944

This might be your problem:

http://www.ross-tech.com/vag-com/aud...es.html#Radios

SloopJohnB@mac.com

dongle in dash.
dongle connected to laptop or pc.
ignition turned ON.

Should work.

Airbag

if You have the ignition on and even a generaic OBD reader wont communicate i would be inspecting the car end closely.. i have NEVER had any generic OBD reader not even communicate ..

05CrewCab

I'll give it a try tonight with the engine running.

I've also heard that if the ABS module is toast it will block the other modules from communicating...hope that isnt the case.

Boston Driver

I had issues with mine, ended up being the fuse, which upon 1st inspection looked fine, but held up to light, it was blown. Almost invisible hairline crack in the fuse. Just look in your manual for the OBD diagnostics fuse. Just can't recall which one it was.

jcman

If you have a ABS/Brake warning in the dash then you need to un-plug the ABS module and VCDS will work.

SloopJohnB@mac.com

Engine doesn't have to be running but ign needs to be on.

Prospeeder

Also improperly installed aftermarket radios will do this too. The cheap wire harness kits label the Can bus wire as a power antenna wire. Even though the car has no power antenna, they hook it up anyway and it kills the comm line and no scan tool communication.