Dear reader,
I want to share with you my experience in making AUX in 3.5mm cable in BMW E46 Business CD.
The sound is really crystal clear!!!
The only negative thing is that you will loose the FADER and BALANCE controls for the Radio and CD player. They will be equalized (centered).
You will have to control the Volume and Equalizer from your phone/mp3 player.
You cannot control the sound from the Business CD!
So, the procedure is as follows:
1. Dissassemble the CD and find this chip: XC390239FU
2. Then solder 2 bridges as shown in the picture (red and white wires)
– These pins are for the Front-Left/Rear-Left and Front-Right/Rear-Right channels. When you solder these bridges the front and the rear lines will be equalized and you cannot control the FADER.
3. Then solder the cable of your 3.5mm jack to these two bridges (left and right channel)
4. Solder the GND of the cable whereever you want on the chassis of the CD.
5. You are ready to enjoy the beautifull sound of your mp3 player! π
boyanmilushev 
How you switches between Radio/CD/Mp3 player?
How you switches between Radio/CD/Mp3 player?
Can you answer :)??
You don’t π
It always plays the music from the external player over the radio or CD.
Mikail: How you switches between Radio/CD/Mp3 player?
Can you answer :)??
boyanmilyshevbobixaka: You donβt π
It always plays the music from the external player over the radio or CD.
Thx for your answer, but I still can’t understand how it works.
You said “It always plays the music from the external player over the radio or CD.” so, does it mean that for example signals (audio) from radio and from aux is playing in one time and it will be some kind of mix? Or maybe when I connect some MP3 player ,XC390239FU choose the signal with higher power? and when I disconnect MP3 player it choose again signal from radio?
Could you try explain me this π
Thanks in advance π
It is like a mixer.
If the radio is playing and you plug in the external mp3 the signal is going to be mixed.
The signal from the external player goes straight to the final amplifier and you have no switch for switching between radio\CD\External player.
Does this affect the radio function?
No. Only the Balance – Fader control… You cannot change it..
If You use some Zener diode You can use Fader control.
Hello, IΒ΄m on my way to do this mod but I have one question, can I after this mod still listen to radio and will I be able to control the radio volyme on the radio itself?
Kind regards
Yes you can control th radio… It does not affect any radio functionality, except the balance – fader control…
The solution I was looking for. Thank you very much!
I have an old E46 radio and did not want to change the original look. Used radios that support aux in natively cost at least 100β¬ and are hard to find.
This costs under 10β¬ and works! Even though the volume cannot be controlled via steering wheel or directly on radio, I can still completely silence it with a push of one button. I simply lower the volume all the way down and put one click up. That way I need to push volume down once to silence it completely. The actual volume control goes over aux device.
In my radio the chip was made by blaupunkt, but has the same layout and code behind the first two letters. Those should actually be MC68HC11 series built for automotive purposes.
—-
I found similar chip on the CD PCB which I could not identify 100%, but the pinout is the same and the functionality should also be the above. Now I would like to try that out, so I could easily switch between radio and CD (aux).
Do you maybe have an idea or could confirm that it could actually work? π
work very well on chip blaupunkt,is the same diagram