[Wind90]

Hello everyone.
I have a 2010 E90 328i. I've encountered an issue where my Aux port works inconsistently. For example, it may work fine for three days, and then for several days it doesn't work. Or it might work fine today, but after I go to the store, turn off the car, and return, it stops working. When it works, it works perfect without any interruptions, so I don't think the issue is with the cable, the port, or the wiring.

When it doesn't work, there’s no checkmark left to it. Normally, when it’s working, I can see a checkmark to the left of the AUX label on the screen. Also, the volume is locked near zero. Additionally, I noticed that when I turn on the ignition, and it’s a “lucky day,” above the “Aux front” text, where the USB label is, I see a "initializing" message for a few seconds, and only after that does it change to “Not Connected.” On an “unlucky day” when the aux isn’t going to work, the screen immediately shows “Not Connected” without the initialization.

I've read some forum threads on similar issues, and some people found the problem to be with the MULF or MULF2 module. But the thing is, I don’t have this module. In the trunk, where the MULF should be, I have another module called TCU. Could it be causing the issue? Meanwhile, Bluetooth and radio and CD is working consistently and without any problems.

Thanks for reading and hepling.

Video:
https://www.youtube.com/shorts/xrAT0mmXauc

[ctuna]

Mulf2 module will be under the TCU in that year car.
That's a TCU 1.5 that you have displayed in the picture.

Aux port source maybe dependent on options installed .

And or head unit .

http://www.e90post.com/forums/showthread.php?t=1181654

[Wind90]

Originally Posted by ctuna

Mulf2 module will be under the TCU in that year car.
That's a TCU 1.5 that you have displayed in the picture.

Aux port source maybe dependent on options installed .

And or head unit .

http://www.e90post.com/forums/showthread.php?t=1181654

I'm not sure where to check the installed options, maybe in this photo.

And yes, the MULF module turned out to be located under the TCU module.
My head unit is CIC, if that's what you mean.
Maybe I should try installing a different MULF module? Do I need to reprogram anything when replacing it?

[ctuna]

Did you try running the Mdecoder.com vin decoder.
(this should give you the installed option numbers)
Do you have a center console USB connector?(suggests 6fl option )
Did you read the Link about TCU and Mulf?(read entry 4 in the supplied link from earlier)
Most of the time replaced module require programming unless they came out of a car
with exactly the same configuration.

There are several versions of the Mulf , Mulf 2 high is the best one see the link .(because it supports USB)

If you are going to do your own DIY's I would suggest you get
a Diagnostic setup consisting of a K/D can cable and
BMW Standard Tools and Ista D.
Finding the Free downloads for these can be more difficult but not impossible
use the coding sub forum and Idrive sub forum .

diagnostic manual ista/inpa
https://www.google.com/url?sa=t&rct=...xo19teM9vkTF-C
https://www.google.com/url?sa=t&rct=...7x8H3pN8h1fMuF
https://bimmerprofs.com/diagnostics-inpa-part-1/
https://www.google.com/url?sa=t&rct=...lkXEhlQYy4i9Nb
https://www.bimmerforums.com/forum/s...-P-actually-do
https://www.bimmerfest.com/forums/at...1&d=1590283589
https://www.google.com/url?sa=t&rct=...kBbC27TJLX3BGe
https://www.google.com/url?sa=t&rct=...WekqhcC6hsgK2c
https://www.e90post.com/forums/showthread.php?t=1649066
primary links
https://www.e90post.com/forums/showthread.php?t=1681573
https://www.nathansbmwworkshop.com/b...or-dean-videos
ista problems
https://www.e90post.com/forums/showthread.php?t=1661945
https://www.e90post.com/forums/showthread.php?t=1581663
https://www.bimmerfest.com/threads/t...-pdfs.1449540/