A Audi radio asks for its security code after the head unit loses its permanent live feed — a flat battery, a battery change, a jump start or the radio being unplugged. The code is held against the serial number of that head unit, not against the registration or VIN. The serial normally looks like AUZ2Z3A1234567. Look for the code card supplied with the car — usually in the service book wallet. Once you have the serial, enter it in the radio code finder on this page.
Radio codes belong to the head unit serial number, not the vehicle registration or VIN.
A flat battery, battery replacement or radio removal is what triggers the code prompt.
Audi serial formats: Concert / Chorus (e.g. AUZ2Z3A1234567); Symphony (e.g. AUZ4Z7B1234567); RNS-E navigation (e.g. AUZ5Z1L1234567).
Display messages: SAFE = Anti-theft lock active — code required. · 1000 = Starting display for code entry. · SAFE + number = Lockout countdown after failed attempts. · Component protection = A vehicle-level lock on retrofitted units — needs coding to the car, not a radio code.
Bob's never displays a guessed or generated code — if a working code can't be retrieved you get a full refund.
Where to find the serial number, what the display messages mean and how to key the code back in on a Audi.
An Audi radio code is a four-digit security code held against the head unit serial. It is not the immobiliser and not the key — it exists only to stop a stolen unit working in another car.
When you'll be asked for the code:
After a flat battery or a battery replacement
When the radio has been removed for dash or amplifier work
After fitting a used Concert or Symphony unit
Following a deep discharge on a car stored over winter
Serial number formats:
Concert / Chorus — for example AUZ2Z3A1234567. A3 8P, A4 B6/B7, A6 C6 — label on the casing.
Symphony — for example AUZ4Z7B1234567. Higher-spec cassette/CD changer units.
RNS-E navigation — for example AUZ5Z1L1234567. Serial shown on the label and in the service menu.
How to find the serial number:
Look for the code card supplied with the car — usually in the service book wallet.
Remove the unit with a pair of U-shaped Audi radio keys pushed into the slots each side until they click.
Read the label on the top of the casing: note the AUZ serial and the part number beginning 8E0, 8P0 or similar.
On RNS-E units the serial can also be read through the service menu, but the label is easier to trust.
Take a photograph rather than transcribing — a single wrong character means a wrong code.
What the display messages mean:
SAFE — Anti-theft lock active — code required.
1000 — Starting display for code entry.
SAFE + number — Lockout countdown after failed attempts.
Component protection — A vehicle-level lock on retrofitted units — needs coding to the car, not a radio code.
How to key the code in:
Press and hold preset 1 to enter code mode on most Concert units.
Presets 1 to 4 step each digit up in turn.
Hold preset 5 or the SCAN button to submit.
SAFE clears and the radio resumes.
Is the Audi radio code the same as VW's? The system is the same VAG design, but the serial prefix differs — AUZ on Audi, VWZ on Volkswagen — and every code is unique to its own unit.
My retrofitted unit says component protection That is not a radio code problem. Component protection ties the head unit to the specific car and has to be cleared with diagnostic coding.
Can I read the serial without removing the radio? Occasionally a hidden menu shows it on RNS-E units, but on Concert and Symphony units the casing label is the practical answer.
How many attempts before lockout? Three is typical, then a timed wait that grows with each further failed round. Verify the serial first.