OBD Interface: Polo 9N - Orange Light Flashing

Guest Free account, no CAN development support

Hello everyone,

I'm unable to access the fault memory on my Polo 9N (engine code: BBY, VIN: WVWZZZ9NZ4Y225605) using my VCDS full version (latest software, DualK & CAN (Hex-CAN, HC 464395 Version A) because I can't establish a connection to the control units. The LED on the interface is blinking orange, indicating a non-operational interface. However, the interface is working correctly because I've tested it on another, very similar Polo, and I can access all the control units on that car without any problems. Furthermore, ATU (a vehicle inspection company) was unable to perform the required vehicle inspection because they also couldn't establish a connection via the OBD connector. They sent the vehicle owner to a Bosch service center for the inspection. I'm going to inquire there about how they performed the inspection. I suspect that the onboard network control unit, along with the diagnostic connector interface installed in it, may be defective. Does anyone have a better idea or has anyone experienced something similar?

I would appreciate responses.

Translated on 11-10-2026, 17:28.

Before the wiring is checked...

Has the battery ever been disconnected for an extended period?

Translated on 11-10-2026, 17:29.

Standard error: Radio problem, replaced with a different aftermarket radio. The DIN connector has the correct shape according to the standard, but the pin configuration is not.

Bertil wrote:

Starting with the G4 generation, the car radio is connected to the diagnostic bus. If an aftermarket radio is installed without a suitable adapter, it can cause voltage on the diagnostic bus. This may not only damage the diagnostic computer, but also some control units.

Best regards, Rainer.

Guest Free account, no CAN development support

Hello Rainer,

Bullseye!! I disconnected the non-original radio and, lo and behold, everything is working again.
The design of the plug should be changed to prevent this from happening.

Thank you very much for this information! I would never have thought of that.
Another proof that this forum maintains a high standard.

Thank you very much and best regards.

David.