[snowymountains]

I'm getting an SOS light and the radio has no sound. Seems that everything else works. I do not have NAV. Also, when I select menu on the radio I can't select phone or assist.

I have tried pushing and holding the power button, the combination of pushing and holding the eject and power button, disconnected the battery for an hour, pulled all the fuses for the radio, etc. I have not been able to do the reset that I've seen others say works.

Nothing has worked.

I've read lots of posts but I'm finding little to no information about my 2006 330xi with no NAV.

I'm a little perturbed because the car has been down the last 3 weeks while I have replaced all wheel bearings, front and rear struts and an axle.

Any info or thoughts on this would be greatly appreciated.

[X_Drive]

Sounds like there is something on your MOST bus that is pulled down.

Check if you accidentally knocked off any connectors w/a green optical cable at
a) TCU/COMBOX
b) AMP under the left rear parcel tray
c) any of the MOST optical cables behind the left rear trunk panel.

The reason I ask is that you replaced your rear struts and when accessing the struts you have to uncover these items and sometimes things happen.

HTH.

[snowymountains]

I just pulled the driver side panel out again, checked around where the strut is and around the amp, and checked the area behind the rear seat.
Can't see anything pulled down...the Check ID is 299 which is the SOS unavailable TCU unit error.

[X_Drive]

Originally Posted by snowymountains

I just pulled the driver side panel out again, checked around where the strut is and around the amp, and checked the area behind the rear seat.
Can't see anything pulled down...the Check ID is 299 which is the SOS unavailable TCU unit error.

Another thing you can do is go to the AMP and look for the MOST connector. Pull it out with the ignition on and see if there is a red light illuminating from it. The most connector will be the connector with the green optical cables. If the light is not on, then one of the control units is not passing off the light correctly. If the light is present, however if its dim, then you may have a kink in one of the cables.

If you can also do this to your TCU. Which is located under your middle trunk tray.

[snowymountains]

Checked both connectors. Bright red light. Although it was periodically flashing. I checked the fiber cable/connector on the satellite radio box and had no light.

Wondering if the TCU is hosed.

[X_Drive]

The periodic flashing is normal. However before the TCU is deemed kaput, turn off the ignition, unplug everything from the TCU and let it sit for, say 5 mins. Then plug everything back in and see if it comes back online.
Hopefully that will hard reset the unit and come back to the light, so to speak.

[snowymountains]

Unfortunately that didn't help.

The exclamation point on the dash cleared for a moment and then the SOS CC-ID 299 showed up and no sound from the radio.

I have read that replacing these will require some programming/coding.

I've been wanting to dive into that stuff but haven't had the time. I'll likely take it to the dealer to see what they say.

Ugh....and it rides so good now with the new Koni FSD's and new wheel bearings!!! But not as fun as when the tunes are not on!

[X_Drive]

Crap. Your TCU most likely has taken a dump. However I cannot say for sure that is the issue. I my trying to think of other things that would dump the TCU.

[snowymountains]

I'm not in a huge hurry. Doing some research to. I'd love to figure out what software I need to be able to see that thing and interact with it.

[grubby669]

I had the same issue once when installing an amp and sub in my car. Luckily for me it was just a fuse. I know it sounds simple but did you check them?

[snowymountains]

I checked what I think are all of the fuses. But the Bentley manual and the ID card on the fuse box behind the glove box did not match. So, maybe, I missed one.

Do you remember the fuse # and was it behind the glove box?

I'm going to be ordering some software as I think I already have adapters that will work. The software I'm looking at appears to be able to interact with the TCU.

[Bori]

Any updates on this? Have the same problem. Code cc-id 299 and radio doesnt work. Thanks

[matteblue3er]

It's very common for the BMW Assist portion of the TCU to fail. Any module on the MOST bus that is malfunctioning will bring the bus down. Also any break in the fiber optic lines can also cause this error. Even leaving the MOST bus diagnostic port loop back connector unplugged will result in this error. This port is located above your driver's kick panel...it's a small 2x2" square you pull down.

MOST bus is your multimedia bus......Head unit/radio, amps, SAT modules, Telecom modules, IPOD, COMBOX, MOST gateway etc are all on this bus and can all bring it down.

You can try removing BMW Assist from the car. To do this permanently via coding, you have to modify the VO/FA and add "+TELD". This will remove the BMW Assist portion of the TCU and leave Bluetooth active.

I have had my car coded like this for 4 years now and Bluetooth is still 100% functional.

[matteblue3er]

Originally Posted by snowymountains

I checked what I think are all of the fuses. But the Bentley manual and the ID card on the fuse box behind the glove box did not match. So, maybe, I missed one.

Do you remember the fuse # and was it behind the glove box?

I'm going to be ordering some software as I think I already have adapters that will work. The software I'm looking at appears to be able to interact with the TCU.

If you are able to pull faults from the module, the fuse is not blown.