[mrgreenwood]

This morning got in my car no sound at all radio it's dead, SOS malfunction it's on my idrive. any ideas what can I do to fixt it

[spoiler]

Sad to hear that my friend... I had this issue last year and after some research i could find any solution hear but to take the car to the dealer. The problem has to do with something called MOST BUS fiber optics the dealer fixed it and i didnt had warranty so i ended up paying $370. If you have warranty just take it to the dealer because its not DYI fix. Hope this helps.

[mrgreenwood]

Thanks for that. I will take it to de dealer thanks again

[jbash87]

I have the same thing happening to me right now. No radio and the SOS warning light. I changed my battery last night, figured all would be fine after a little driving but still nothing. Is the dealership really the only option? Note: I haven't gotten the new battery "registered" yet, could this solve the issue?

[mrgreenwood]

If you found any information please let me know

[spoiler]

For me dealer was the only option since i dont know any fiber optics which could be several things that could be malfunctioning.

[sea335i]

Any luck? I had the same thing, plus my idrive went complete black, but the SOS appeared on the speedometer. I replaced the CCC unit, but now theres no sound, no door or seat belt chime thinking its the L7 amp

[mrgreenwood]

My idrive stil work navigation works fine everything but no sound at all

[M BROK3]

when I was retrofitting my bluetooth into the car I had to mess with the MOST connections behind the rear seat and once they were disconnected I lost sound from radio and SOS error popped up. Don't know if that can be the issue of a wire coming loose but I will check it just in case.

[jbash87]

Just heard from the dealership. They want to replace the fuse box saying the "bi-stable relay" is sticking. Anyone ever heard of this? Please help can I replace the fuse box myself? The dealer wants $803 for this!!!

[mrgreenwood]

Do u have any pictures of the wiring behind rear seat

[Excorcist]

i have the same problem keep me posted if you find a cure!

[Frank2808]

I had the same issue and the dealer ended up replacing the combobox. Was covered under warranty.

[afsar]

This problem generally means there is something wrong with the MOST bus, here are the possibilities:

1) One of the unit on most bus is dead/non responsive

a) Check BT unit, its most connection, its power connection, its fuse.
b) Check L7 unit for the same as above
c) Check CDC unit for the same as above
d) Check HUD for E6x for the same as above
e) Check any other fibre optic connected device like TV,DVD changer etc for the same as above

2) Open most bus connection

If MOST port is left opened, e.g. the port for OPS (in the glovebox) somehow become loose and its connector came off, very rare but possible.

3) Broken/twisted most bus fibre optic wire

Super rare but possible, if problem appeared after recent change/retrofit then look for twisted/damaged fibre optic wire

Problem will be among these possible situation. Generally I have seen if power is disturbed to a most unit then it simply breaks the most ring and you get this problem. To isolate it you need to buy most bypass part from dealer and you can individually bypass each component to see if problem is due to that unit. Isolate and identify is the key to work on ring topology network.

[jbash87]

I forgot to update you guys after I went to the dealership. They told me that "bi-stable" relay was stuck open causing the radio and SOS not to function. When they had the car hooked up to the computer, they were able to force the relay shut, but could not guarantee that it would never happen again. After that the radio worked fine and no SOS light was flashing for a couple weeks.

Well, it happened again when my battery went dead (a different issue all together). From what they said, this relay is soldered to the fuse box (not sure why anyone would think soldering a relay to the fuse box is a good idea) which means they want to replace the entire thing.

I have no plans to pay the dealership $800+ to replace the fuse box for some silly relay. I plan to remove the fuse box this weekend and see if I can't isolate the relay that is stuck open. I'm hoping that I can replace it myself (I'm more than confident in my soldering abilities to do this, depending on how tight the board is). Otherwise I suppose I will need a replacement fuse box.

Anyone fix this problem for good w/o replacing the fuse box?

[mrgreenwood]

if u do that post some pics please

[carlosalbertogui]

Originally Posted by mrgreenwood

My idrive stil work navigation works fine everything but no sound at all

you have to buy new TCU --- Telematic control unit

the TCU is located on the trunk.


best regards

[mrgreenwood]

TCU its a plug and play? Or have to be coded

[marius76]

if you buy used or new unit you should program it and code plus transfer your account.
try to take your car to the dealer and ask to perform diagnosis or as afsar wrote buy MOST loop, disconnect fiber optic cable from TCU and connect MOST loop. If audio will work then you have an issue with TCU unit. Also check if there is a power comming to TCU.

[carlosalbertogui]

Originally Posted by mrgreenwood

TCU its a plug and play? Or have to be coded

can someone code TCU

A TCU (telematic control unit) can Only be ordered by specifying the Vehicle identification number. The VIN is coded when the replacement TCU is delivered. Recoding is not Possible. The TCU functions properly Only with matching coding. Replacements TCUs cannot therefore be ordered in Reserve! Retrofits and conversions To SA633 are not possible...

i have SA633 .......
now a have a SOS call System error everything else is working as i should be ....

any help

[tinnsoldaten]

Originally Posted by afsar

This problem generally means there is something wrong with the MOST bus, here are the possibilities:

1) One of the unit on most bus is dead/non responsive

a) Check BT unit, its most connection, its power connection, its fuse.
b) Check L7 unit for the same as above
c) Check CDC unit for the same as above
d) Check HUD for E6x for the same as above
e) Check any other fibre optic connected device like TV,DVD changer etc for the same as above

2) Open most bus connection

If MOST port is left opened, e.g. the port for OPS (in the glovebox) somehow become loose and its connector came off, very rare but possible.

3) Broken/twisted most bus fibre optic wire

Super rare but possible, if problem appeared after recent change/retrofit then look for twisted/damaged fibre optic wire

Problem will be among these possible situation. Generally I have seen if power is disturbed to a most unit then it simply breaks the most ring and you get this problem. To isolate it you need to buy most bypass part from dealer and you can individually bypass each component to see if problem is due to that unit. Isolate and identify is the key to work on ring topology network.

I disconnected the panel under steering colum during routing of some cables , I disconnected everything that was connected to the panel , panel is not installed yet , but I put power back on , and when key is in , I get the SOS symbol , no need to worry once I hook everything back together again?

And I have one more issue you might could help me with ...

http://www.e90post.com/forums/showth...battery+charge

[azeteg]

I had a similar issue with my non-navi system on the E70 LCI. I had the following symptoms:

- SOS Call system failure
- Aux input not working
- USB input not working
- Phone screen stuck on "Please wait..."
- Bluetooth option greyed out
- Trunk lights not working

The issue started after replacing the trunk lights with LEDs.

I followed the circuit diagrams on http://www.bmw-planet.com/diagrams/r.../e70/index.htm and found that the TCU, USB and the trunk lights are wired to the rear power distribution box. Fuse #110 was burnt. Replaced the fuse, and everything worked fine again.

The fuse chart shows a telephone symbol for fuse #110, might be helpful for people with other BMW models.