745i navigation, radio, and sound system problem

Help.. how do i bypass... where do i find this unit and what do i do?

Also when most bus is stuck you won't have any navigation working plus idrive is not responsive.
Most bus is everything in BMW, all multimedia is driven by fibre optic cables, if signal is lost - all devices are screwed up automatically. Looks like very few people here understand something in electronics.... Read something and life would be easier if you own a BMW

Originally Posted by Has8223

Help.. how do i bypass... where do i find this unit and what do i do?

go to the dealer and buy a new amp get ready to spend 1500$ or so..


or buy a MOST jumper and bypass it,, but in this case you won't have L7 sound.

if you in south africa your L7 is fried completely.

yes if there is a problem with the l7 he wont be able to use anything. but it will throw a code on the screen right away. has8223 can you take a picture or a video of ure car on and you trying to use your i drive system?

Yes, i am in SA. $1500 in SA terms is a cart full of cash... don't care for the L7 sound just want the radio working... How do i go about bypassing with MOST jumper? thanks for reponse...

Originally Posted by Has8223

Yes, i am in SA. $1500 in SA terms is a cart full of cash... don't care for the L7 sound just want the radio working... How do i go about bypassing with MOST jumper? thanks for reponse...

here is what you need copied Keif message:
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One of the items on the MOST bus ring has tanked or you have an issue with one of the fiberoptic cables. MOST = Media Oriented Systems Transport. A MOST bus jumper / FOC coupler (fiber optic couple) - part: MOST 61 13 6 917 541 - can be used to eliminate / bypass specific devices on the network until the offender is found. Before that, try pulling out the FOC in the the glove compartment fuse box for a few seconds to give a simple MOST bus reset a shot.

no need to ... i can explain... i see the telephone... blank screen for nav... only se FM & AM on radio... basically i see all the other options but am unable to do anything with them ...

Originally Posted by Has8223

what is amp l7 and where do i find it so that i ca replace

I'd try turning the Battery Switch OFF in the Boot/Trunk ...then leave it for about 30 mins or so ....then turn it back ON and see if it's made any difference......

If it's still not working after that then (as mentioned above) your next step is to start bypassing each suspect Module with a MOST Bus Loop Connector.

Originally Posted by irokdastar383

yes if there is a problem with the l7 he wont be able to use anything. but it will throw a code on the screen right away. has8223 can you take a picture or a video of ure car on and you trying to use your i drive system?

its not going to throw any codes, you just cant operate your idrive at all

try it disconnect your L7, BTW its the same as reseting MOST bus

Originally Posted by TechFreak

I'd try turning the Battery Switch OFF ...then leave it for about 30 mins or so ....then turn it back ON and see if it's made any difference......

If it's still not working after that then your next step is to start bypassing each suspect Module with a MOST Bus Loop Connector.

Yeahh, also pray some gods, cross your fingers on both legs while standing

let the guy buy a jumper and feel happy tricks won't help find the faulty MOST device, but almost 100% its L7, at least strat from it.

Originally Posted by N60B44

Yeahh, also pray some gods, cross your fingers on both legs while standing

..........................I wasn't joking !!!

Distribution mode

By switching over the battery switch to the OFF position, the power module goes into distribution mode function 30 minutes after Terminal R switches off. Before disconnecting, the power module sends out the "Shutdown" signal. After a further 90 seconds, the shut down is executed.

After terminal R On, a Check Control message is displayed to inform the driver that the vehicle is in the distribution mode.

When the signal terminal 15_w (from the Car Access System) is detected or the battery switch is set to ON (closed-circuit current monitoring), the electronic battery main switch is closed.

The vehicle can also be started and driven in the distribution mode. All systems are able to operate. The Check Control message remains active. With terminal R Off, the shutdown is initiated once again after 30 minutes as described above.

Power Down command

This function enables the control units to be placed in sleep mode.

Thanks.. will try! where is the switch... i am an accountant and direction is what i need when it comes to technical matters

Originally Posted by TechFreak

..........................I wasn't joking !!!

Distribution mode

By switching over the battery switch to the OFF position, the power module goes into distribution mode function 30 minutes after Terminal R switches off. Before disconnecting, the power module sends out the "Shutdown" signal. After a further 90 seconds, the shut down is executed.

After terminal R On, a Check Control message is displayed to inform the driver that the vehicle is in the distribution mode.

When the signal terminal 15_w (from the Car Access System) is detected or the battery switch is set to ON (closed-circuit current monitoring), the electronic battery main switch is closed.

The vehicle can also be started and driven in the distribution mode. All systems are able to operate. The Check Control message remains active. With terminal R Off, the shutdown is initiated once again after 30 minutes as described above.

Power Down command

This function enables the control units to be placed in sleep mode.

if MOST BUS reset didn't help.... nothing would help... already tried, battery off switch is located on the rear right fender. Just open the door where the battery is, on the top you will see a black switch with on and off, it was designed to prevent discharging battery when your car is istting more than a week withit driving.

Originally Posted by Has8223

Thanks.. will try! where is the switch... i am an accountant and direction is what i need when it comes to technical matters

The Battery Switch is beside the (round Green) Emergency Fuel Filler Release which is in the top right in this photo :

thanks... it is 10pm here.. can i leave it off overnight and check if all is well in the morning.... do i put back to on position in morning and check ?

Originally Posted by Has8223

thanks... it is 10pm here.. can i leave it off overnight and check if all is well in the morning.... do i put back to on position in morning and check ?

Yep you can do that .....it may not make any difference but worth trying.

thank you very much.. i will keep you posted... will sleep standing up, crossed fingers and pray that thsi fixes the problem otherwise i will just go to BMW and empty out my wallet, credit card and savings to fix the problem...

just make sure you have a key to open the trunk cause ure remote wont work

didn't need it this morning.... worked without the key... but still no radio... will remove the amp and send off for repairs..

Originally Posted by Has8223

didn't need it this morning.... worked without the key... but still no radio... will remove the amp and send off for repairs..

where you sending your amp to???

Originally Posted by Has8223

didn't need it this morning.... worked without the key... but still no radio... will remove the amp and send off for repairs..

I'd buy a Most Bus Loop 1st to test the modules to be sure ....as DrewBimmer said earlier in this thread...........it just bypasses your AMP or module via fibre optic to see if the rest of the modules are working......

http://www.bimmerfest.com/forums/sho...4&postcount=27

will do... so the process is take the FOC out from the L7 unit and plug the MOST FOC that i buy into this? Is this correct?

I'm in South Africa... will have to send to some tech around here?

btw we checked if the L7 unit is getting power and it seems as if it is... but the cooling fan does not go on... a question, i see the FM, AM and cd on my screen but cannot access them ... could this fault not lie in the cd loading unit?