Optical Loop SOS

Andrewah05 · 05-26-2024, 11:59 AM

Hey all,
Been chasing this SOS malfunction error, shop said it was TCU got one that was exact same plugged it in and still issues. When I loop it around TCU I get everything back besides bluetooth, does that mean the amplifier, is good and all the other components? My last thing is to change the mulf should I loop the Mulf and see what happens?

Thanks,

Drew

ctuna · 05-26-2024, 01:36 PM

Do you have a L7 amp aka HK aga Hi Fi system option 677 or 688.
If you do you will have not sound when the most loop is broken
(not complete) . You can loop out as many modules as you have
jumpers for.

If you have a mulf 2hi you dont need a TCU for anything it can be programmed out.
The mulf 2hi will take care of the same functions as the TCU if properly coded.

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

Weather the TCU is in or Bad you will still get TCU errors till the programming is changed
so the car stops scannining for the TCU status or ignores it.
When TCU's are removed the the Kombi module (intrument cluster must be programmed to ignore
the absent TCU and the TCU must be fully dissconected from the electrical connectors at the rear of
the module.

Andrewah05 · 05-26-2024, 01:45 PM

Quote:

Originally Posted by ctuna

Do you have a L7 amp aka HK aga Hi Fi system option 677 or 688.
If you do you will have not sound when the most loop is broken
(not complete) . You can loop out as many modules as you have
jumpers for.

If you have a mulf 2hi you dont need a TCU for anything it can be programmed out.
The mulf 2hi will take care of the same functions as the TCU is properly coded.

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

Weather the TCU is in or Bad you will still get TCU errors till the programming is changed
so the car stops scannining for the TCU status or ignores it.
When TCU's are removed the the Kombi module (intrument cluster must be programmed to ignore
the absent TCU and the TCU must be fully dissconected from the electrical connectors at the rear of
the module.

Awesome thanks

ctuna · 05-26-2024, 02:38 PM

If you plug in a good TCU and it was the TCU that was bad every
body that did that reported it worked. The only thing is the module
may retain the VIN number from the donor car only noticable when pairing.
BMW stopped supporting the SOS funtion in 2006 or 2007 for the
TCU as 2g networks disappeared.

My TCU went bad when I programmed it out in the Instrument Cluster I would
still get a TCU error when the car started and the main electrical connector to the TCU
was still plugged in that went away when unplugged.

There is much more info on these kind of things on the stereo sub forum and coding sub forum here.

Andrewah05 · 05-26-2024, 04:31 PM

Quote:

Originally Posted by ctuna

If you plug in a good TCU and it was the TCU that was bad every
body that did that reported it worked. The only thing is the module
may retain the VIN number from the donor car only noticable when pairing.
BMW stopped supporting the SOS funtion in 2006 or 2007 for the
TCU as 2g networks disappeared.

My TCU went bad when I programmed it out in the Instrument Cluster I would
still get a TCU error when the car started and the main electrical connector to the TCU
was still plugged in that went away when unplugged.

There is much more info on these kind of things on the stereo sub forum and coding sub forum here.

How can I tell if the TCU I got is good, plug it in and see if most cable has a red light on the fibre cable?

ctuna · 05-26-2024, 04:49 PM

If you had a good tcu and the tcu was the only thing wrong you would
just plug in all the cables and it would work .
There is no bench setup for these .
Also if you had the coding setup you could read values from the programming
parameters in the tcu. this would only be basic check it would not check the bluetooth or the phone function.

I would dump the TCU as it's now worthless and get Mulf 2 Hi going with option 6FL or get and aftermarket device like a Mr12volt to do the same functions and more. Unless you like the OEM functions.

Andrewah05 · 05-26-2024, 04:56 PM

Quote:

Originally Posted by ctuna

If you had a good tcu and the tcu was the only thing wrong you would
just plug in all the cables and it would work .
There is no bench setup for these .
Also if you had the coding setup you could read values from the programming
parameters in the tcu. this would only be basic check it would not check the bluetooth or the phone function.

I would dump the TCU as it's now worthless and get Mulf 2 Hi going with option 6FL or get and aftermarket device like a Mr12volt to do the same functions and more. Unless you like the OEM functions.

I never used the bluetooth, I think ill just loop it. I do like the OEM. Going to exchange this one i got and hope for the best.

Andrewah05 · 05-26-2024, 05:01 PM

Quote:

Originally Posted by ctuna

If you had a good tcu and the tcu was the only thing wrong you would
just plug in all the cables and it would work .
There is no bench setup for these .
Also if you had the coding setup you could read values from the programming
parameters in the tcu. this would only be basic check it would not check the bluetooth or the phone function.

I would dump the TCU as it's now worthless and get Mulf 2 Hi going with option 6FL or get and aftermarket device like a Mr12volt to do the same functions and more. Unless you like the OEM functions.

You mentioned the VIN, does it have to be coded, its the same part number but from a 11 323i

ctuna · 05-26-2024, 09:03 PM

No but in the phone system it reads the Vin to use SOS so when
you will see the last for digits of the Vin in the phone pairing process
it the bluetooth is running off the TCU and not the Mulf 2 or Mulf 2 hi .

Andrewah05 · 05-27-2024, 12:07 PM

Quote:

Originally Posted by ctuna

No but in the phone system it reads the Vin to use SOS so when
you will see the last for digits of the Vin in the phone pairing process
it the bluetooth is running off the TCU and not the Mulf 2 or Mulf 2 hi .

Ahhh, gotcha. Which program do I use to check this, NCS, Winkfp? Their is no communication either way just curious.

ctuna · 05-27-2024, 05:49 PM

If it doesn't communicate you have bigger problems.
To check communication Run Inpa functional jobs F3 and F4
This will give you a view of all the modules that the car is currently communicating
with . They should all be there.

Its always good to run this before any kind of programming attempt.

Winkfp has been the one used to change Vin numbers on modules.
You need to to the coding subforum and read up on this stuff.

05-26-2024, 11:59 AM	#1
Andrewah05 Captain 78 Rep 660 Posts Drives: 335i TiAg Join Date: Sep 2012 Location: Toronto, Canada iTrader: (0)	Optical Loop SOS Hey all, Been chasing this SOS malfunction error, shop said it was TCU got one that was exact same plugged it in and still issues. When I loop it around TCU I get everything back besides bluetooth, does that mean the amplifier, is good and all the other components? My last thing is to change the mulf should I loop the Mulf and see what happens? Thanks, Drew
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05-26-2024, 01:36 PM	#2
ctuna Lieutenant General 2098 Rep 13,467 Posts Drives: 325xi 06 wagon MT Join Date: Jan 2010 Location: Santa Cruz, Ca iTrader: (0)	Do you have a L7 amp aka HK aga Hi Fi system option 677 or 688. If you do you will have not sound when the most loop is broken (not complete) . You can loop out as many modules as you have jumpers for. If you have a mulf 2hi you dont need a TCU for anything it can be programmed out. The mulf 2hi will take care of the same functions as the TCU if properly coded. http://www.e90post.com/forums/showthread.php?t=1181654 Weather the TCU is in or Bad you will still get TCU errors till the programming is changed so the car stops scannining for the TCU status or ignores it. When TCU's are removed the the Kombi module (intrument cluster must be programmed to ignore the absent TCU and the TCU must be fully dissconected from the electrical connectors at the rear of the module. Last edited by ctuna; 05-26-2024 at 02:42 PM..
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05-26-2024, 02:38 PM	#4
ctuna Lieutenant General 2098 Rep 13,467 Posts Drives: 325xi 06 wagon MT Join Date: Jan 2010 Location: Santa Cruz, Ca iTrader: (0)	If you plug in a good TCU and it was the TCU that was bad every body that did that reported it worked. The only thing is the module may retain the VIN number from the donor car only noticable when pairing. BMW stopped supporting the SOS funtion in 2006 or 2007 for the TCU as 2g networks disappeared. My TCU went bad when I programmed it out in the Instrument Cluster I would still get a TCU error when the car started and the main electrical connector to the TCU was still plugged in that went away when unplugged. There is much more info on these kind of things on the stereo sub forum and coding sub forum here.
	Appreciate 0 Quote

05-26-2024, 04:49 PM	#6
ctuna Lieutenant General 2098 Rep 13,467 Posts Drives: 325xi 06 wagon MT Join Date: Jan 2010 Location: Santa Cruz, Ca iTrader: (0)	If you had a good tcu and the tcu was the only thing wrong you would just plug in all the cables and it would work . There is no bench setup for these . Also if you had the coding setup you could read values from the programming parameters in the tcu. this would only be basic check it would not check the bluetooth or the phone function. I would dump the TCU as it's now worthless and get Mulf 2 Hi going with option 6FL or get and aftermarket device like a Mr12volt to do the same functions and more. Unless you like the OEM functions.
	Appreciate 0 Quote

05-26-2024, 09:03 PM	#9
ctuna Lieutenant General 2098 Rep 13,467 Posts Drives: 325xi 06 wagon MT Join Date: Jan 2010 Location: Santa Cruz, Ca iTrader: (0)	No but in the phone system it reads the Vin to use SOS so when you will see the last for digits of the Vin in the phone pairing process it the bluetooth is running off the TCU and not the Mulf 2 or Mulf 2 hi .
	Appreciate 0 Quote

05-27-2024, 05:49 PM	#11
ctuna Lieutenant General 2098 Rep 13,467 Posts Drives: 325xi 06 wagon MT Join Date: Jan 2010 Location: Santa Cruz, Ca iTrader: (0)	If it doesn't communicate you have bigger problems. To check communication Run Inpa functional jobs F3 and F4 This will give you a view of all the modules that the car is currently communicating with . They should all be there. Its always good to run this before any kind of programming attempt. Winkfp has been the one used to change Vin numbers on modules. You need to to the coding subforum and read up on this stuff.
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