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Old 11-09-2012, 02:18 PM
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Technic Technic is offline
OEM Audio PnP Integration
Location: Florida
Join Date: Jun 2002
Posts: 7,925
Mein Auto: 2017 M3
Originally Posted by hondo402000 View Post
no there is no USB function on the radio menu, when I press the audio button only Tuner, CD, AUX show up
what is the MULF?

if the radio head unit shows AUX, what is it for if not associated with the AUX port?
I can only go by what the BMW guys told me and that is if the AUX button is pressed and I plug my Ipod headphone out to the AUX in, I should get music but I have to select songs thru the IPod menu.

I would guess that no music is heard via AUX when you plug the iPod headphone jack to the AUX port, regardless of the volume of the iPod and the radio, correct?

The MULF is the module that controls the USB and the AUX port, as stated before.

By not having sound via the AUX, just having charging power via the USB and not having the USB selection when an USB device is plugged into the USB then the logical conclusion is that there could be something wrong with the MULF module.

The technician should have determined that without wasting your time.

At least it is a fact that there is a MULF installed in your car. My advice is to get a cheap USB stick, put some MP3 songs in it and try it in that USB port. You should see the USB selection in the radio and the songs should play.

If the USB shows up in the radio menu, and music plays fine then the USB section is functional but somehow the AUX port is defective. It could be the actual port jack, the wiring between the jack and the MULF or the MULF itself. Getting the OEM "Y" iPod cable will not help as you will have control and display of the iPod contents via the radio but no sound. Sound with the OEM "Y" cable is routed via AUX... the same AUX that is defective.

If nothing happens -no USB in the menu, no songs played with the USB stick- then the module must be defective; when both the USB and the AUX are defective then it must be the MULF itself that it is defective -they do not share any cabling or the ports.
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