Audi A4 factory radios lock themselves and show SAFE when the battery is disconnected. You need the 4-digit code that matches the radio's serial number.
Is this your radio?
The radio's name ("chorus", "concert" or "symphony") is usually printed on the front. The serial on the label starts with AUZ. A4 models with MMI navigation screens use a different system, which doesn't use a 4-digit code.
Commonly fitted to the A4 B5, B6, B7 and B8 (including Avant and Cabriolet), with factory radios such as the Chorus, Concert, Symphony and Navigation Plus (RNS-E). Exact fitment varies by year and trim.
Step 1: find the AUZ serial
The code is tied to the radio's serial number, printed on a label on the radio's casing. It's 14 characters and starts with AUZ, for example AUZ1Z2A1234567. Don't use the part number, which starts with digits.
To read it, slide the radio out of the dash. Most units come out with radio release keys; some are held by Torx T20 screws behind a trim panel. There's no need to unplug it. More detail: where to find your radio serial number.
Step 2: get the code
First check the service book wallet for a radio code card whose serial matches your radio. If there isn't one, you can order the code from the serial: £24.99, delivered by email in 1–3 hours on average.
Need your Audi A4 code? Original 4-digit code from your AUZ serial: £24.99, 1–3 hours on average, money-back guarantee.
Get my codeStep 3: enter the code
- Switch the ignition on and the radio on. The display shows SAFE.
- Hold TP and RDS together for about 2 seconds to bring up the code entry screen, which usually shows 1000 or 0000.
- Set each digit with preset buttons 1–4. Button 1 changes the first digit, button 2 the second, and so on. Each press counts up by one, and 9 wraps round to 0.
- Confirm by holding TP and RDS together again for 2–3 seconds until the radio plays.
The exact buttons can differ slightly between versions. Our Workshop Manual has a press-count planner if you want to plan the presses first.
The Navigation Plus (RNS-E) sat nav shows its own code prompt on screen instead: follow it to set the four digits, then confirm.
Quick answers
Where is the serial number on a Audi A4 radio?
On a label on the radio's casing, usually the top or side. It is 14 characters long and starts with AUZ. You normally need to slide the radio out to read it.
How much is a Audi A4 radio code?
£24.99 from RadioUnlock, fixed price, delivered by email in 1–3 hours on average, with a money-back guarantee if the code doesn't work.