Radio won't turn off? Troubleshooting tips

Translated on 16-09-2026, 4:34.

Hello, I've already searched the history, but I couldn't find anything related to my error.
This concerns an Audi A3, model year 2002, which has a Chorus system installed.
The problem manifests as follows: I can turn the radio on using the power button.
But if I remove the ignition key, it keeps playing.
Now I've removed the device and discovered that there is no S-contact.
more than that, in my opinion, all of that stuff goes through a data bus

.
Replacing the device did not bring any success either

.
Okay, I've now read the error memory (for the radio), and there's an entry indicating a problem with the data bus in the control panel.
no communication

Has anyone ever experienced a problem like this before

?
And it solved

.

dieselschrauber · Translated on 16-09-2026, 4:39.

Solution!!!!!!!!!!!!!!
I wanted to follow up and let you know that the problem was indeed the data bus, which could be identified by the uppermost connector socket on the radio.
This information can also be found in the wiring diagram of the radio housing (CAN). When I tried to measure the data bus at these pins...
(Using a quick oscilloscope), I saw only 9 volts with the ignition on, and no data signal. This led me to suspect that...
The combination is defective because the S-signal was supposed to arrive there! (Think again.)

Unfortunately, it's necessary to register the bus devices in the instrument cluster, which probably hasn't been done in my case.
"This was done, because I can't imagine that the instrument cluster would forget its coding!"
The problem was history when I performed the adjustment.

All original Audi radios from the model year 2002 onwards are CAN-bus compatible.
The table applies to vehicles manufactured from 2002 onwards.

Translated on 16-09-2026, 4:44.

herold4 wrote:

I wanted to follow up and let you know that the problem was indeed the data bus, which can be identified by the uppermost connector socket on the radio.

Thank you for the solution!

Translated on 16-09-2026, 4:44.

Perhaps a little off-topic, but if someone finds this article while searching, they will probably be interested in this link (it has certainly helped me before): http://www.selfmadehifi.de/kfz-iso.htm