ULF Bluetooth Volume problems/Error Code 204

[bcworkz]

Mine should be 65126976889 but I haven't actually pulled it to confirm. Too bad you didn't catch me earlier, I did have it out, but not planning to in the near future. If it was REALLY useful, I could pull it just to check, but for mere curiosity I think not. Sorry.

You're probably right, any Business CD after Oct 2004 probably has compatible internals. Yeah, I can't imagine approaching a stranger in a car park and asking "Mind if I have a go with your head unit?" :? Maybe you could go to a breakers and they'd let you borrow one for a few minutes to ensure it works "before buying" it?

 

[Mangozac]

No drama I didn't expect you to do it just for me

I guess I'll just keep an eye on the used market. Maybe ring some wreckers too...

 

[Mangozac]

Searching for used BMW parts is a real pain. I figured it would be easy: simply look up the part number to check the part details on realOEM. But I've been finding that a lot of part numbers don't exist (or on other parts websites are marked as "no longer available"). From what I've read this is because parts like the Business CD are subject to "remanufacture". The remanufactured parts are given a new part number (it usually seems to be just the old part number incremented by 1) and this is what's listed by RealOEM. This makes it really hard to cross reference part numbers.

Does anybody know of a more comprehensive part number source? What I need is a listing of all Business CD units that are compatible with all E85 Z4s, both original and remanufactured part numbers.

 

[Stuart Truman]

I've got the Nav unit and suffer the same volume issues, so not 100% if the head unit is the issue. I wonder if it's the differntial volume, like that of the nav, which is either near silent or deafening. I don't see an adjustment for the BT module though

 

[Mangozac]

No, there is no adjustment for the BT volume on the Business CD (even in the hidden configuration menus).

Could you explain the differential volume thing further?

 

[yg54sg]

i have the full DSP carver system, the bluetooth audio-in from the bluetooth module I believe plugs into the cd player as a line level signal next to the aux in cable. It has always been in my mind to splice this cable and fit a simple 12v audio in-line preamp with adjustment control to boost the signal coming from bluetooth audio out... At the moment to get round the problem I always just grab the volume knob on the radio while in call to turn up the caller which is acceptable until you have the roof off.

 

[Mangozac]

Yeah the telephone audio signal is indeed adjacent to the aux in pins on the back of the head unit. If you read earlier in this thread though I have tried a line level preamp in line with the telephone signal without any luck. While I could get a little bit more volume, it started to distort before enough gain was reached. This would indicate to me that the problem is inside the head unit, nut between the ULF and head unit.

At least turning the volume knob up in call makes enough of a difference: even if I do that it's still too quite to have a conversation

 

[yg54sg]

Sorry I must have missed that post when i read through Thanks for trying I will cross that off the list! I think there are some other pins for the sat nav voice prompt input that are active all the time regardless of what source is selected, I wonder what would happen if you piggybacked onto these from the bluetooth module and what sort of volume you would get. If too loud a potentiometer could be introduced somewhere along the line, perhaps on that panel thats easily removable under the heater controls out of sight.

 

[Mangozac]

No worries, glad to have spared somebody else the effort

While there are spare pins on the back of the Business CD head unit, I'm pretty sure they will not be connected internally. And even if so, they won't be selected when the TEL_ON (telephone on) signal is asserted. They are probably only used on the CID control head units.

 

[jamiez]

Any updates on this thread?
Did anybody get this resolved under warranty at all?

 

[sammysquid]

sorry to bring a thread back from the dead.... any update?
I did see somewhere that if you have the bm24 with dsp then you have to splice into the dsp but that doesn't apply with the bm54 I believe?