Center Console Aux/USB Not Working, 12V OK

sonick · 11-26-2018, 10:45 AM

Hi all,

Having a tough time troubleshooting why the USB/Aux in my center console are not working.

Not trying to get iPod/iPhone control setup, I just want my aux input to work.

Here's the symptoms:

BMW Professional Radio shows Tuner, CD, and Aux In, no USB option
12V in center console works
No voltage/power via USB (i.e. phone or iPod doesn't indicate 'charging')
No sound from aux, no crackle when plugging in/out

Having done some reading, I am hoping it's just the fuse for the ULF unit, however I am having a tough time figuring out which fuse/circuit is responsible for this.

Another idea could be the radio itself wasn't coded properly (i.e. missing USB option).

Any thoughts?

sonick · 11-27-2018, 11:09 AM

Spent some time trying to trace this down more, I think I narrowed it down to a faulty mulf2 high unit. Looks like the previous owner put in an optical loop to bypass the mulf2 high and went straight into the TCU unit that's in there.

leagues58 · 01-07-2019, 02:06 PM

Were you able to fix this/definitively determine the cause of the problem? I am experiencing the same symptoms but bypassing the MULF2 didn't seem to help anything.

printerror · 01-30-2019, 10:24 AM

The USB port in mine wasn't working when I bought the car. I pulled it apart to find that the pins were bent in the socket. $4 on eBay got me a 25 pack of USB female sockets (I have a few extras) and I simply soldered on a new one. BMW wanted $50 to replace the jack, I fixed it for about fifteen cents.

11-26-2018, 10:45 AM	#1
sonick New Member 5 Rep 11 Posts Drives: 128i Join Date: Nov 2018 Location: Vancouver iTrader: (0)	Center Console Aux/USB Not Working, 12V OK Hi all, Having a tough time troubleshooting why the USB/Aux in my center console are not working. Not trying to get iPod/iPhone control setup, I just want my aux input to work. Here's the symptoms: BMW Professional Radio shows Tuner, CD, and Aux In, no USB option 12V in center console works No voltage/power via USB (i.e. phone or iPod doesn't indicate 'charging') No sound from aux, no crackle when plugging in/out Having done some reading, I am hoping it's just the fuse for the ULF unit, however I am having a tough time figuring out which fuse/circuit is responsible for this. Another idea could be the radio itself wasn't coded properly (i.e. missing USB option). Any thoughts?
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11-27-2018, 11:09 AM	#2
sonick New Member 5 Rep 11 Posts Drives: 128i Join Date: Nov 2018 Location: Vancouver iTrader: (0)	Spent some time trying to trace this down more, I think I narrowed it down to a faulty mulf2 high unit. Looks like the previous owner put in an optical loop to bypass the mulf2 high and went straight into the TCU unit that's in there.
	Appreciate 0 Quote

01-07-2019, 02:06 PM	#3
leagues58 E82 25 Rep 12 Posts Drives: 2011 128i Join Date: Sep 2012 Location: South Carolina iTrader: (0)	Were you able to fix this/definitively determine the cause of the problem? I am experiencing the same symptoms but bypassing the MULF2 didn't seem to help anything.
	Appreciate 0 Quote

01-30-2019, 10:24 AM	#4
printerror Private 45 Rep 51 Posts Drives: 2011 BMW 128i 6MT Join Date: May 2016 Location: Jax Beach FL iTrader: (0)	The USB port in mine wasn't working when I bought the car. I pulled it apart to find that the pins were bent in the socket. $4 on eBay got me a 25 pack of USB female sockets (I have a few extras) and I simply soldered on a new one. BMW wanted $50 to replace the jack, I fixed it for about fifteen cents.
	Appreciate 0 Quote