Pololu Robotics & Electronics
My account Comments or questions? About Pololu Contact Ordering information Distributors

Pololu Forum

Getting back a very wanted car radio code - hopefully!

Hello everyone,

I want to share my first Pololu project with you.

A friend of mine asked me to reset the radio code of its most loved car. He got the car from his late father, the code is now lost in time. The radio is a Becker Mexico CD 876, very well known to any Mercedes-Benz enthuisiast. Becker used to provide car radios for Mercedes-Benz up to the late 1990s. This one is special, because it was initally ordered with this car (a 1991s 560 SEL, which was a very exensive car at this time). Even Mercedes-Benz or other specialist could not recover the code (which is legal), because the required code chips are no longer available. Besides, this radio was quite expensive. Very expensive. And rare today.

Thinking about a solution I visited the Pololu website. So here wo go, solution found! Thanks for all that stuff, Pololu!

Here it is, the result on YouTube (sorry, remarks in German, same as described here):

I decided to create a mechanical solution. I neither wanted to open the radio, nor do it any other harm.

It took some woodwork, some screws, some light, much adjustment. The heart of the machine though is 10 servos and the Maestro 12 channel controller.

It is controlled by Visual Basic and is running now for 3 days. Day or night.

This solution is only possible, because especially this radio allows to enter 3 codes before waiting another 15 minutes. Other radios wait 24 hours or more or totally lock up.

It will take another 30 days to enter all of the 10.000 codes (4-digit).

This is exiting to watch. Runs perfeclty. Any 15+ minutes it goes “zzzt.” “zzzt.” “zzzt.”

The camera will let me know when the right codes was found.

And yes: I used a very good external 5V power supply for the servos. And a used 12V car battery for the radio. And yes: I checked the forum first :slight_smile:

Let’s wait and see. I will let you know, whenever this was successful.

Thank you Pololu, this loved radio might get back to work.

Kind regards,


Wir warten auf das Ergebnis. Viel Glueck beim Versuch!

Hello, Christian.

Wow, thank you for sharing this exciting project! We can’t wait to see the result! We plan to share this on our blog soon.


Hello everyone,

I just want to let you know that 50% of all possible codes are entered (this afternoon). This means 5.000 in total! Although the right code is still hiding somewhere in the radio :question: , I am glad (really glad :smiley: ) that everything still works fine.

I faced some minor problems though: My laptop freezed twice, for whatever reason. Rebooted it and set up everything again. That was easy.

More worrying was the fact, that the radio locked up once. At first I thought that this was due to stucking servos or too few power (I mean the car battery connected to the radio). But that was not the case, so I disconnected it for a while. Since then it works again like before. As of the Pololu hardware: on and on and on and on …

Any news will be added here.

Kind regards



Hello, Christian.

Thank you for the update! All of us are rooting for you!