VAG COM: No Connection T5 2008 (German)

Translated on 30-09-2026, 5:31.

Hello, experienced VAG enthusiasts,

I'm having a problem; I can't connect to the internet.

Subject: VW T5, 2008, 2.5 TDI, 128 kW, BPC engine.

I am using VCDS (Vag COM) version 3.11 in German, and I have a serial adapter from Rosstech that I purchased from Kaufmann about 6 years ago (here on this forum).
"It has always worked so far... even with my T5, 2.5 TDI, AXD engine."

At the interface, there is a box with 4 LEDs, and the 4th LED, which is red, always lights up as soon as I connect via the OBD2 interface.
Nothing is lit up here.

Are there any experiences with this yet?

Best regards,
Klaus.

Translated on 30-09-2026, 5:33.

Hello Klaus,

If the red LED is illuminated on other cars but not on yours, it could be because the connector is not properly plugged into the OBD2 socket, or the contact for pin 16 (on-board voltage) has become dislodged within the socket.

As software, VCDS-Lite 1.2 is the current version, so you don't have to use any questionable versions, because version 3.11 in German was never sold or distributed by me.

Best regards, Rainer.

Translated on 30-09-2026, 5:34.

Dear Rainer,

Thank you very much. This will be reviewed soon (after Christmas).
VAG 3.11 is a full version, and not from you! But the connector

and the fifth one are perfect!

Even the friendly one couldn't establish a connection...

I will report...

Best regards,
Klaus.

Translated on 30-09-2026, 5:35.

Hello,

In this case, let's check if +12V and ground are present at the connector. Pinout:
/viewtopic.php?t=3089 (roughly at the end)

Best regards, Rainer.

Translated on 30-09-2026, 5:36.

Hello Rainer,

"Thank you, that's exactly what I was looking for!"

Thank you very much!

Best regards,
Klaus.