[E91 Hoarder]

My 2006 non-iDrive Professional radio unit has burnt pixels.

Trying to replace it with the Professional unit from 2011 car. However, after swapping the units the speakers make a pulsing sound. The sound continues even when the car is off.

Any ideas how to solve this?

- original 2006 Professional unit is Alpine 65126971703. It has a black plug and one black optical connector
- replacement 2011 Professional unit is 65129246504 with blue plug, black and red optical connectors.

See the video:

[codeterrorist]

I got the same thing when I was installing mr12volt bluetooth box to allow for music streaming and retain steering wheel controls.

This same pulsing sound happened when I unplugged the fiberoptic cable from the back of the TCU in the trunk. Or if you remove it from any of the module on the MOST loop while the car has power (battery plugged in) and should go away once plugged back.
Make sure all your fiberoptic plugs are seated properly.

[E91 Hoarder]

Originally Posted by codeterrorist

I got the same thing when I was installing mr12volt bluetooth box to allow for music streaming and retain steering wheel controls.

This same pulsing sound happened when I unplugged the fiberoptic cable from the back of the TCU in the trunk. Or if you remove it from any of the module on the MOST loop while the car has power (battery plugged in) and should go away once plugged back.
Make sure all your fiberoptic plugs are seated properly.

Thanks so much for replying!

Not sure, I am clear what to do exactly. Would you please explain the sequence of steps?

[codeterrorist]

Just make sure your optical connector is seated at the back of the radio unit.
You will also most likely need to code the replacement radio to your car.
I use Protool by BimmerGeeks to do this kind of coding, there are other tools that you can use of course.

[E91 Hoarder]

I see - thanks!

- I have the Protool, but when I looked, not sure which option to code in. These are both Professional HUs
- Any idea what the red connector is for?

[ctuna]

Put up a picture.

[E91 Hoarder]

Originally Posted by ctuna

Put up a picture.

Pic of the back of the HU

[ctuna]

https://www.bimmer-tech.net/blog/ite...sy-diy-upgrade

Those are antenna connectors one goes to the diversity module the other goes to
a satellite antenna which you probably do not have.

As for the pulsing put the other radio back in and see if its still there.
Maybe you got a bad radio.
No reason for it to do that .
Also when you buy a Radio and replace it you usually have to program it for
the type if sound system you have.

[E91 Hoarder]

Originally Posted by ctuna

https://www.bimmer-tech.net/blog/ite...sy-diy-upgrade

Those are antenna connectors one goes to the diversity module the other goes to
a satellite antenna which you probably do not have.

As for the pulsing put the other radio back in and see if its still there.
Maybe you got a bad radio.
No reason for it to do that .
Also when you buy a Radio and replace it you usually have to program it for
the type if sound system you have.

Put the original back in. No pulsing sound. The replacement radio works fine - tested in its original car before pulling it.

[ctuna]

Was it programmed for the same sound system of which there are three.
There are quite a few versions of the CD73 radio also .

[ctuna]

Was it programmed for the same sound system of which there are three.
Did you try coding it to your car?
Do the pins on the main connector look the same between the two
are there any bent pins on the new one?

[codeterrorist]

Since you have Protool, just go to the radio module and select factory coding. This will use the FRM or CAS to pull the VO and code the radio unit accordingly.