[xdrive330xi]

Please help.

My radio on my 2006 330xi cuts in and out. It also turns on and off. It appears the radio is dead. If I were to unplug it and replug it the radio would work for a few mins and then cuts out. I believe the radio is defective.

Does anyone know if I can just buy another OEM radio unit and install it or do I need the dealer to reprogram it for the new OEM radio to work?

I was able to remove the old oem radio, just don't know if the new one will be plug and play. Anyone know?

[ctuna]

All the 330's in the US came with logic 7
There is an amp in the trunk under the drivers side corner.

http://www.e90post.com/forums/attach...2&d=1266451970

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

http://www.e90post.com/forums/attach...1&d=1209780605

[xdrive330xi]

How do I know if it is the amp or the radio head unit?

It makes no sense to me that the radio would work if I unplug it and replug it. It will only work for sometimes seconds and sometimes minutes before it cuts out completely. Does it sound like the amp? If the radio is the defective item, it shouldn't work at all. Correct?

[fdriller9]

Has your car ever been in an accident? Breaks in most loop can cause what you are experiencing.

[xdrive330xi]

Yes it has. I was rear ended once, but the bumper was scratched only. No dents. What does "breaks in most loops" mean?

[fdriller9]

Originally Posted by xdrive330xi

Yes it has. I was rear ended once, but the bumper was scratched only. No dents. What does "breaks in most loops" mean?

The MOST loop is a fiber optic communications system within our cars. The head unit is on this loop and uses the fiber optic network to communicate to different modules.

If there is any break in the MOST loop, it will disrupt and even freeze all modules within the loop.

So if you got in an accident, the connections may have been bumped out of place where it's close enough to get a connection, but far enough to easily break the connection when any vibrations or movements are applied.

Can you expand on what you mean by your radio doesn't work? Does it become unresponsive? Or does just the audio cut out?

[xdrive330xi]

Thanks for taking the time and explaining this to me. This has been a frustrating issue.

When I unplug my radio and replug it from the back of the radio, the radio is fully functional. I can turn up the volume, change stations, etc. After a few mins, the radio will shut down by itself. Sometimes I can see the LCD display dimming while there is no sound and then the LCD dispay shuts down completely. Sometimes I hear a click sound right before the display and audio shuts down. Once the radio shuts down completely, I can not turn it on at all. No display, no audio. The ambient lights on the buttons are still all on on the radio when I have my headlights on, but is completely unresponsive to any buttons I push. I can't turn it on.

[ctuna]

http://www.bmwradiorepair.com/?gclid...FccbQgodIEn0Cg

[xdrive330xi]

So anyone know how I can find out if it is the amplifier in the trunk that is bad or the radio?

[bimmer03231984]

same situation.t he radio works properly, everything works and the radio seems to be running by no audio is coming out from the speaks. also when i turn the volume knob, there is no volume indicators like it use to.

not sure if i should try to unplug the radio. let me know what happens. thanks

[ctuna]

Or anything has an intermittent connection vibration could cause it go in an out. If you were rear ended then the most likely place to start is there. You will
need to swap stuff to isolate unfortunately.
If the amp is bad an goes bad once it warms up this would also cause the problem unfortunatly. Not many people complain about the radio failing for anything but the pixel display so the amp is more likely.

[Shawnthebomb]

This happens to me as well. Rarely, though.

Originally Posted by *********

The MOST loop is a fiber optic communications system within our cars. The head unit is on this loop and uses the fiber optic network to communicate to different modules.

I'm having similar issues about 50% of the time where the radio will randomly "freeze" and I can't change the volume, or the source, etc.

I've read in older threads that a MOST jumper can be used to bypass the amp and a few other modules to try and narrow down the problem. Before ordering a MOST jumper from Tischer, where should I plug the jumper into to try and isolate the cause of this freezing issue?

[fdriller9]

The freezing issue can also be caused by a faulty TCU or a phone that is not compatible with the TCU. The later will give you a SOS error with a phone with a line through it.

I used to get these errors with my iPhone 3GS but every since upgrading to the latest version of iOS 4 (I know there is iOS 5), I haven't had a problem. I just used to reset my iDrive and all was fine. It happens every now and then but much less then before.

You would use the jumper to join the 2 fiber optic cables together to join the loop back up. So behind the HU, or amp, or at the TCU. Basically where ever a module will be splitting the fiber optic cables.

I don't have nav and haven't tried pairing my phone through Bluetooth yet (had the car for a couple weeks now), but will keep that in mind.

Where exactly is the TCU located?

Thanks!

[ctuna]

Under the floor cover behind the rear seats
or the forward section of the trunk floor.

Just an update to my issue: I ordered the jumper and bypassed the TCU a few weekends ago. All seems to be working well so far and the radio hasn't frozen since When it get's warmer out I'll start fiddling with it again by maybe trying to reset the unit itself or possibly try to find a replacement, etc. Do these units tend to go bad? If so, maybe trying to source one from a junkyard would be a bad idea...

Just wanted to say thanks again for the help!

[jsunma]

Originally Posted by FCobra94

JDo these units tend to go bad? If so, maybe trying to source one from a junkyard would be a bad idea...

They do go bad. I had mine replaced under warranty because the bluetooth started to randomly disconnect. I was told by the dealer that there were "codes stored" that indicated a bad TCU.

But be aware that the TCU must be coded to the car to work. Each needs to be specific to the car's VIN. It's possible to do the recode, but unless you have the right tools for coding, it's not a DIY or plug-and-play solution. I'd personally be leery of using a junkyard part as it's electronics and you might end up spending money to get (and code) a bad one. Better to get a properly rebuilt one from BMW (and then you might as well get the dealer to install it and code it properly). Although I'm sure that someone on here knows just how to code it and might point you the right direction.