[Alturiak]

I have recently started having this weird issue with all my music inputs besides radio and music stored on the car's internal hard drive. USB connection with my iphone, bluetooth, and aux inputs all have a loud static noise that plays through all speakers when selected and it's driving me nuts... Any ideas what could be causing this? Is it possible my MULF is going out and I just need to swap in another one?

Any help is greatly appreciated!

[ctuna]

Which sound system do you have? Base , Hi Fi or L7/hk
You must have idrive since you said hard drive.
The Aux and USB inputs come throuth the combox or
TCU/Mulf. Its possible those could be going bad.

If you have streaming bluetooth music it will mean you have
a combox since it is the only module that supports this.

http://www.e90post.com/forums/attach...2&d=1260829447

These modules are located in the same area as the TCU in the above
document.

If you have a TCU mulf combo the mulf is under the TCU.

[Alturiak]

Originally Posted by ctuna

Which sound system do you have? Base , Hi Fi or L7/hk
You must have idrive since you said hard drive.
The Aux and USB inputs come throuth the combox or
TCU/Mulf. Its possible those could be going bad.

If you have streaming bluetooth music it will mean you have
a combox since it is the only module that supports this.

http://www.e90post.com/forums/attach...2&d=1260829447

These modules are located in the same area as the TCU in the above
document.

If you have a TCU mulf combo the mulf is under the TCU.

Hi ctuna, sorry yes I have hifi audio, upgraded to bavsound speakers and bimmertech amp. Is there a way to test the mulf to see if it's the culprit?

Since bluetooth goes through the combox, could my combox also be going bad? Is there also a way to test the combox to see if its still good?

[ctuna]

First I would just try a visual inspection and re seating
the cables, to the Mulf/Combox .Do you know if its a Mulf 2 Hi or a Combox yet?

Also did you try re seating the connectors at the USB and Aux Port
in the center console?

I bet the bimmertech amp sounds nice.
Doesn't that also have and Aux or USB Input.

As a test you might try going through the aux on that.
That was a stray thought I don't think it helps to isolate
things but it my be a better input than the OEM aux fidelity
wise.

https://www.newtis.info/tisv2/a/en/e...check/GIYBFEsY

Possible fault patterns during the load test

The USB port voltage is too low.

Troubleshooting:

Check USB cable connection between IMIB and vehicle.
Check wires and plug connections in vehicle.
Check the USB connection.
Check control unit.
Check fuse.

Load current was not reached at the USB port.

Troubleshooting:

Check USB cable connection between IMIB and vehicle (use spare cable from another IMIB if necessary).
The customer may have attached a USB hub (distributor) to the vehicle USB connection. Always run the USB test directly on the USB connection in the vehicle!
Check the USB connection.
Check wires and plug connections in vehicle.
Check control unit.

[Alturiak]

Thanks! I definitely recommend the amp, sounds sooo much better, especially with the chassis tune so everything is centered for the driver.

Awesome, I'll take a look back there and re-seat the cables. I'm not sure about the inputs on the amp, I know at least a usb input since you can connect to computer with it. I'll take some pics and report back

[Alturiak]

Sorry, it's been raining here nonstop and I don't have a garage so I haven't had a chance to get back there to check connections. I'll also take a pic of what I have so you can see exactly what I'm working with.

If I need to swap out my MULF, how do I code it? Is it through NCS, and if so which module is it under?

[ctuna]

The name will be on the module .
My first guess for this would be faulty or warn out
connectors though.

It will be either Mulf 2 Hi or combox.
If its a mulf 2 hi there may be a usb hub in between.

Go to the tis site pick your model and do a search for ulf
and combox and the related diagrams and procedures will
come up . Got to thank George for showing me that site
it's really valuable.

Yeah raining a lot here to.

If you buy a used module an get lucky and its programmed
for your same optons about the only thing you need to do
or would want to do is change the Vin number in the module.
Most use tool32 for that.

Other wise you can do what is called a default code from the
VO in the car where it writes the stored info form the CAS or FRM
that the car came with for that module back in . Or you could
make a copy before you change the module out . If it was me
I would make a copy just to see what's in it. (The way you do
when you code a module)

[Alturiak]

Okay so I was able to get back there today to check things out. I had one box back there, and all the connections on it looked perfect. I took a couple pics to show you what I have. I couldn't confirm the part number though since I didn't have tools with me to pull it out and see the label on the bottom side. I unplugged and plugged everything back in and the problem is still there... any other ideas for tests to run?

[ctuna]

My guess is its a combox . Every TCU and Mulf 2 hi I have seen
have been labeled. You need to verify that.
Next step would be to try to locate another one I think.
Get the part no and look on ebay.
Some coding may be necessary.

Labels are probably underneath or in back.

[Alturiak]

Sorry for digging this up again, but I lost my car for about a year and wasn't able to work on this issue. I'm picking it up now though.

So I've identified that unit in my trunk not as a MULF or TCU, but as the combox unit. It's a 2011 with HiFi audio and Bluetooth, USB, AUX, etc- the car was fully loaded when I purchased it.

I've ordered a MOST bypass loop to see if that helps with anything for testing/identifying bad units. At the moment I'm suspecting the combox as having gone bad but would like to positively identify first before committing the money to buying a new one.

For swapping in a new combox, does it need to be coded? And is it better to buy a new one that doesn't have the wear and tear of a used one (but at way higher cost), or just buy a used one and hope it lasts long?

Any further input to help me resolve this issue would be greatly appreciated

[Alturiak]

I just wanted to update this thread in case it helps someone in the future. I started experiencing the sound issues after installing an AVIN Android head unit in the car. It was a huge pain to get it in and after install I wasn't sure what happened and put off tearing everything back apart to remove the system.

Flash forward to this week and I finally decided to remove it, to only discover the issue was that their shitty connector that attaches to the CIC drive had misaligned the MOST cable connection, and it ended up pushing the connectors on the CIC side into the clip, not being connected at all. So that is why I lost AUX, BT, and USB all at once.

I was able to fix that connection and when I attached everything it was all working! So I kept the AVIN unit in and reinstalled and am now back to enjoying my BT, USB, and AUX connections