Golf IV/Audi A4 Diagnostic Interface

First of all, good day to everyone in your forum; it's really great what I've read so far.

I would also like to delve into vehicle diagnostics using VAG-COM.

I've also built an interface based on the standard minimal wiring diagram, and it seems to be working fine. The VAG-COM software recognizes the interface and doesn't report any errors.
I'll get the OBD connector later.

Here are some questions to get us started:
What type of diagnostic interface does the fourth-generation Golf use?
I mean, are we talking about a K and L line or two K lines?

2. And what about the Audi A4 1.9 TDI from 2001 with 96 kW? And where is the OBD connector located on that model?

I'm just asking because otherwise I would be building my own "worst-case scenario" version 4.0 interface.

"3. What about the CAN bus in newer vehicles? Are there any wiring diagrams available for such an interface?"


Best regards,

1. What type of diagnostic tool does the Golf 4 have?

A K-line.

2. And what about the A4 1.9 TDI manufactured in 2001 with 96 kW? And where is the OBD connector located on that model?

Possibly 2 K-lines, depending on the configuration.

http://de.openobd.org/einbauorte.htm#audi_a4_8d

3. What about the CAN bus in newer vehicles? Are there circuit diagrams available for such an interface?

It will not happen.

Thank you for the information.

How can I determine if the A4 2K uses two K-lines or not? The second K-line is located where the L (live) wire would normally be, so you can't tell by looking at the connection layout.

A professional interface displays which diagnostic connections are available.

http://www.ross-tech.com/vag-com/tour/screens/4090/4090options_test.png

In your case, one would have to make a general conclusion based on the equipment.

Which model is your A4: the 8D or the 8E?

To be honest, I don't know, but the manufacturing date is June 2001.

How can I tell the difference between an 8E and an 8D?

Hmm... well, is it the current model (before the facelift), or is it the older model?

Otherwise, the vehicle identification number (VIN) is listed there as well.

Theresias wrote:

A professional interface displays which diagnostic lines are available. In your case, one would have to make a general conclusion based on the equipment. Which model is yours, an A4 8D or already an 8E?

Can the "worst case version 4" interface be used to test whether it supports k-L or K-K?

Can you use the 'worst case version 4' interface to test whether it's k-L or K-K before proceeding?

More likely it's either 'K' or 'KK'.

As far as I remember, this test can only be performed with original interfaces from Ross-Tech.