[help] MULF dead, how to save my AUX input

Dr U · 02-21-2020, 09:53 PM

Hi, I have a 07 E93. A few days ago the SOS call system malfunction error popped up, and the bluetooth and USB input option disappeared, Sat and AUX input grayed out on iDrive.
My car has both TCU and MULF. I located the problem to be a dead MULF. I used a optical fiber loop to bypass MULF, the SOS error disappeared, bluetooth and USB did not come back, Sat came back, and AUX was still gray.

I wonder if I can save my AUX input. I guess the USB port inside the armrest goes to the MULF while the AUX port inside the armrest directly goes to the head unit, is that right? In that case a dead MULF should not affect the AUX input...

Another weird thinking... I know some BMW come with TCU only, no MULF. I wonder if this option has AUX input? If it does, is there any way to change my wiring or coding into this type?

Please help me to save my AUX input. Thanks!! (I know I can buy another MULF anyway...)

ctuna · 02-21-2020, 10:24 PM

Aux goes to mulf in most cases.

Why bother with a TCU when you can get a Mulf 2 hi

You might be able to program the head unit to use the aux
connection on the back of the idrive if you have one but it
would probably require and ICOM cable to program it.

Mulf' 2 Hi is are pretty cheap on ebay.

https://www.newtis.info/tisv2/a/en/

In some cases you will have both a TCU and a Mulf.

If you had usb 6fl option you have a mulf 2 hi .

https://www.newtis.info/tisv2/a/en/e...sbx-h/Hv9hyQrX

Dr U · 02-21-2020, 11:57 PM

Quote:

Originally Posted by ctuna

Aux goes to mulf in most cases.

Why bother with a TCU when you can get a Mulf 2 hi

You might be able to program the head unit to use the aux
connection on the back of the idrive if you have one but it
would probably require and ICOM cable to program it.

Mulf' 2 Hi is are pretty cheap on ebay.

https://www.newtis.info/tisv2/a/en/

In some cases you will have both a TCU and a Mulf.

If you had usb 6fl option you have a mulf 2 hi .

https://www.newtis.info/tisv2/a/en/e...sbx-h/Hv9hyQrX

Ah yeah, mine is MULF2Hi... I know it is cheap though, just want to see if there is a no-cost repair haha.

Dr U · 02-27-2020, 08:28 PM

Update:
So I finally bought a used MULF2HI for 60 bucks. Plug and play, AUX came back, no SOS error anymore, no coding needed! I guess the USB input may still need coding, but who care? I just need the AUX input, together with a bluetooth to AUX adapter, to play music from my phone. Thank ctuna for your reply!

02-21-2020, 09:53 PM	#1
Dr U Registered 0 Rep 4 Posts Drives: 07 BMW 328i (E93) Join Date: Feb 2020 Location: San Diego iTrader: (0)	[help] MULF dead, how to save my AUX input Hi, I have a 07 E93. A few days ago the SOS call system malfunction error popped up, and the bluetooth and USB input option disappeared, Sat and AUX input grayed out on iDrive. My car has both TCU and MULF. I located the problem to be a dead MULF. I used a optical fiber loop to bypass MULF, the SOS error disappeared, bluetooth and USB did not come back, Sat came back, and AUX was still gray. I wonder if I can save my AUX input. I guess the USB port inside the armrest goes to the MULF while the AUX port inside the armrest directly goes to the head unit, is that right? In that case a dead MULF should not affect the AUX input... Another weird thinking... I know some BMW come with TCU only, no MULF. I wonder if this option has AUX input? If it does, is there any way to change my wiring or coding into this type? Please help me to save my AUX input. Thanks!! (I know I can buy another MULF anyway...)
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02-21-2020, 10:24 PM	#2
ctuna Lieutenant General 1911 Rep 13,101 Posts Drives: 325xi 06 wagon MT Join Date: Jan 2010 Location: Santa Cruz, Ca iTrader: (0)	Aux goes to mulf in most cases. Why bother with a TCU when you can get a Mulf 2 hi You might be able to program the head unit to use the aux connection on the back of the idrive if you have one but it would probably require and ICOM cable to program it. Mulf' 2 Hi is are pretty cheap on ebay. https://www.newtis.info/tisv2/a/en/ In some cases you will have both a TCU and a Mulf. If you had usb 6fl option you have a mulf 2 hi . https://www.newtis.info/tisv2/a/en/e...sbx-h/Hv9hyQrX Last edited by ctuna; 02-21-2020 at 10:59 PM..
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02-27-2020, 08:28 PM	#4
Dr U Registered 0 Rep 4 Posts Drives: 07 BMW 328i (E93) Join Date: Feb 2020 Location: San Diego iTrader: (0)	Update: So I finally bought a used MULF2HI for 60 bucks. Plug and play, AUX came back, no SOS error anymore, no coding needed! I guess the USB input may still need coding, but who care? I just need the AUX input, together with a bluetooth to AUX adapter, to play music from my phone. Thank ctuna for your reply!
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