kevesp

Okay quick update: I decided to pull the radio back out to see if I could find something I may have missed. Disconnected the battery and pulled the radio back out and inspected everything and it all looked good. Wrapped some wires in electrical tape just to be sure and put everything back together and and reconnected the battery. This time, however, the unit turned on, but nothing popped up on screen and you can hear the navigation disc spinning rapidly inside, the lights were on (the knob light, the lights by the slots, and the lights on the buttons - its the lights that come on at night when your headlights are on), and still no tones. Tried hard reboot and nothing, and even with the key out and the car locked, the unit never stopped running. Pulled fuse for it just so it won't kill my battery.

Took it to BMW today and had them run diagnostics. They told me that there was an open circuit which could be why my unit acted the way it did, and he also said the TCU was not responding. He told me he could not connect to any other module because the TCU was "bad" and recommended I replace that before continuing. He said the CCC unit looks fine for now, however he cannot guarantee anything until the TCU is replaced.

He told me everything runs on fiber optics, and if 1 unit is bad it stops the flow of communication because of it. Is this true? Has anyone ever had a problem with their TCU going bad which caused their CCC unit to act up? I don't want to replace something that could have nothing to do with my CCC not working. BMW won't replace my CCC until they can confirm the unit is actually bad which they said they cannot verify until the TCU is replaced and they can communicate with every other module.

Thoughts?? What should I do?? Stealership wants $1000 for a new unit and coding and diagnostics of the whole system?????

jtbgonesailing

BMW makes a fiber optic patch cord that is used to remove a module from the fiber optic bus to isolate module failure. Surprised dealer wouldn't have taken the extra step. The patch cord is available through the parts department of dealerships and on line I guess.

kevesp

Well if that TCU is bad I'd rather get it replaced than just remove it and bypass it. I didn't know that was available and could have been done to test it out. I'm looking around for a used one and will replace it myself and get it coded by a friend and save me that $1000. If that doesn't work, then I will bring it back and have the stealership look at it again and do their stuff.

Read around and found out the TCU could actually affect the radio and nav, which could be why my unit is doing what its doing. Hopefully that failing module didn't cause damage to the CCC unit.

jtbgonesailing

What i was suggesting is to use the patch cord to confirm wether it is the TCU by taking it out of the loop and seeing how the CCC reacts.

There is a thread going on now on the TCU. Take a look and join in...
SOS /Bluetooth / Radio Malfuntion - Bimmerfest - BMW Forums

kevesp

Is there a part number for it I can give the dealer? I will go back and get one and see if that fixes the issue.

jtbgonesailing

Sorry I have not had a need for it, knock on wood. Search on this forum and the other I referenced above, as there was a discussion on the bus and how to use the patch cord, within the last year.

kevesp

Ordered a loop today and should be coming in to the dealer tomorrow. Any tutorials out there on how to use it and bypass the TCU?

kevesp

Okay quick update: got the fiber loop from BMW and bypassed the TCU. Sadly, that did nothing as my radio still won't work, and now I have the SOS error appearing on the cluster.

I noticed that on the screen even though I have the fuse pulled on the radio, and even with it in, there's like snow or lines that appear on the screen though faintly. I hope that makes sense. But even though the CCC unit is not powered with the fuse out, or even with the fuse in, the screen is displaying, or trying to display something.

Any other thoughts of ideas? I'm now leaning towards a bad CCC unit, again. Any other modules I can try bypassing now that I have the loop?

kevesp

Alright final update and a new problem...

Took my car bac to dealer where I got the refurbished unit. Asked them to either repair or replace it. They were nice enough to repair it for me for a $100 fee (since I didn't have them install and code it after I bought it from them). Everything now works perfectly, but now my aux jack is making really weird annoying noises, like a staticky noise, and when I accelerate you can hear a whining sound. Jack never used to do that but now suddenly it does? What happened and how can I fix that?