dsorensn

This afternoon I connected my Ross-Tech Hex-USB with laptop running the latest VCDS version into my A8 and found that it could only read the engine controller (# 01). For all other controlers VCDS signalled "No Response from Controller". I then tried to read the controllers on my Allroad and it worked fine.

Does anyone know if there is there some special lock or security mechanism on the A8 that need to be turned off?

williebone

I assume you did turn the Key to Accessory correct? Plug In Control > Turn Key > Plug In USB > Start Software > Test USB Connection > Save > Play!

dsorensn

Yup. I have both cars sitting side by side in the garage and it works with the Allroad just fine, but will only communicate with the engine controller on the A8.

Since CAN bus is a serial interface if the VAG-Com can talk to the one controller that rules out the cable as well as the PC and the software...

tashakes

You need to have the HEX+CAN interface, not sure which one you have, but the A8 will only work with the HEX+CAN. Hope this helps.

dsorensn

Bing-Go! That's probably it:

http://www.ross-tech.com/vcds/canbus.html

Luckily Ross-Tech has a trade-in / upgrade program!

Thanks for the help!

williebone

Man that was too easy to miss! I shouldn't assume. Thanks and laters,

Mister Bally

Just read the thread and right after the original post I said to myself; "you need the interface w/ Control Area Network CAN/J1939" for D3 A8's. Otherwise it may partially communicate.

My '01 Beetle works with the other interface but I just use the Hex+CAN for everything.

dsorensn

New Ross-Tech USB-CAN interface arrived today, works like a champ!

Now I just have to figure out what all of the codes mean......