A Mercedes-Benz 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 BE1234. Check the handbook wallet — Mercedes supplied a code card with most vans and cars. 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.
Mercedes-Benz serial formats: Becker Audio 10 / Audio 30 (e.g. BE1234); Alpine / Sound 5 (e.g. AL1234567); Audio 20 / COMAND (e.g. A1234567890).
Display messages: CODE = The four-digit security code is required. · WAIT / SAFE = Timed lockout after failed attempts — keep the ignition on. · ERR = Incorrect code entered.
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 Mercedes-Benz.
The Mercedes radio code is a four-digit anti-theft code stored against the head unit serial. It is separate from the vehicle's own electronics, so a radio moved from one Sprinter to another arrives locked.
When you'll be asked for the code:
After a flat battery — very common on Sprinters and Vitos left standing
After a battery replacement or terminal disconnection
When a used Audio 10 or Sound 5 unit is fitted
Following auxiliary battery failure on vans and campers
Serial number formats:
Becker Audio 10 / Audio 30 — for example BE1234. C-Class, E-Class, Sprinter — BE prefix on the casing label.
Alpine / Sound 5 — for example AL1234567. A-Class, Vito and later Sprinter units.
Audio 20 / COMAND — for example A1234567890. Later systems, often vehicle-coded rather than four-digit locked.
How to find the serial number:
Check the handbook wallet — Mercedes supplied a code card with most vans and cars.
Mercedes units very rarely display the serial, so the unit comes out on a pair of U-shaped extraction keys.
Push the keys into the slots either side of the fascia until they click, then draw the unit out squarely.
Read the label on the top or side of the casing, noting the BE or AL prefix in full.
Disconnect the battery before pulling the unit on airbag-equipped dashes.
What the display messages mean:
CODE — The four-digit security code is required.
WAIT / SAFE — Timed lockout after failed attempts — keep the ignition on.
ERR — Incorrect code entered.
How to key the code in:
Use the preset buttons 1 to 4 to set each digit on Becker units.
On Sound 5 units the arrow keys set the value and the OK button advances.
Confirm with a long press on the last preset or the OK button.
The unit returns to normal play once accepted.
Where is the Mercedes radio code card? Usually in the handbook wallet or the service book. On ex-fleet Sprinters and Vitos it is often missing, which is when the serial route is needed.
My Sprinter radio says WAIT The unit is in a lockout after failed attempts. Leave the ignition on so the countdown runs. Turning the key off restarts the timer.
Does COMAND need a radio code? Generally no. COMAND and Audio 20 systems are coded to the vehicle rather than protected with a classic four-digit audio code, which is a dealer-level job if disturbed.
Can I get the code from the VIN? Only the factory-fitted unit relates to the VIN. If the radio has been changed — extremely common on working vans — the VIN answer would be wrong.