[RayLivingston]

MY 2007 335i has the (cr@ppy) Business Audio system. Just like with the Harmon Kardon system in my E46, the radion reception has gotten steadily worse over the years. On the E46, there are two electronic modules, one on each C-pillar, one being the antenna amplifier, the other.... I have no clue. But, cleaning all the connections on those modules, and their connections to the rear window heating grid (which also acts as the antenna), supposedly improves reception.

I assume the E90 has similar modules buried somewhere, that suffer similar problems.

Where are they?

How are they accessed?

Any other problem areas I should know about?

Regards,
Ray L.

[RayLivingston]

Found it! Behind the cover at the rear-center of the headliner, just ahead of the third brake light. Cleaning the connections seems to have made no difference.

Did find you can see the signal strength, using a test mode built into the radio. Turn the radio off, then back on. Press and hold the "m" button for about 8 seconds, until the radios serial number is displayed. Then use the +/- buttons to scroll through about a dozen different menus (most of which, I have no clue what they are...). Eventually you will see one showing a small bar graph, which is the signal strength. Mine kinda sucks - 2 bars out of 5.

I'd like to get at the antenna, under the "shark fin", but the shark fin is actually glued to the roof with urethane adhesive, which has to be cut with a razor knife to remove it. I'll save that for after all other options fail to get results.

Regards,
Ray L.

[ctuna]

Shark Fin has nothing to do with FM Radio reception its all in the
rear window unless you have a Convertible in which case there is
a roof down and a roof up antenna.

http://www.e90post.com/forums/attach...2&d=1260829447

electical e90 pdf
http://www.google.com/url?sa=t&rct=j...,d.cGU&cad=rja
http://www.google.com/url?sa=t&rct=j...85464276,d.cGU
http://www.google.com/url?sa=t&rct=j...85464276,d.cGU

[RayLivingston]

Lots of good information there! Thanks!

Where/how did you find those?

Regards,
Ray L.

[ptpending]

it all in newtis.info or bmw rheingold / ista software

[ctuna]

georges links
https://www.bimmerfest.com/forums/at...9&d=1539905743

The above is best compiled list I have seen .
Also there is some stuff if you search in the root directory's hear.

Diversity antenna module seems to go bad a lot which also does
the remote functions.

bmwcoders.com has a pretty good list if its still maintained.
The pdf's are basically training files.

Ista D as mentioned is highly worth having guided trouble shooting
in English and it comes with the tis. Searchable parts and procedure
lookups. Takes some effort to set up but worth it.