If you have disconnected your Audi battery, your Symphony radio will now be asking for the code. In order to input the security code on it, proceed the following steps:

Step 1. Press and hold “SCAN” and “RDS” buttons at the same time,  until 1000 is displayed on the screen.

Step 2. Change the numbers using the “1”, “2”, “3” and “4” buttons.

Step 3. Once you have the code inserted and correctly displaying on the screen, Press and hold “SCAN” and “RDS” buttons at the same time until the radio starts to work normally.

This tutorial works on all Audi A2, A4, A6, A8, TT equiped with the Symphony radio.