BMW F15 X5 MOST Bus Fiber Optic Sequence Needed

[virtualbong]

Hey guys, I am trying to diagnose what module in my 2015 F15 X5 is failing in the MOST sequence. I have not been able to find any direct guide that outlines the sequence that the MOST take in order to troubleshoot all devices. Here is some background on my situation.

Vehicle:
2015 F15 X5 w/ Harmon Kardon system
Issue description:
No sound coming from any of the speakers. I have noticed that I can gain access to all of the radio functionality and my phone can connect to Bluetooth and even displays what's playing on my apple music. Navigation also seems to be working as it can locate my vehicle. I have not tried to utilize the navigation though
Steps to resolve so far:
1. Replaced the Harmon Kardon Amplifier with Bavsound Amplifier. This did not resolve the sound issue
2. Replaced the Bluetooth Module. This did not resolve the sound issue

My next step is just to walk through everything. I purchased one of those Optical loops so that I can test each module but I wasn't sure exactly where everything was except for the amplifier and Bluetooth module and also the sequence. Does anyone have a diagram or something?

Any recommendations? I have been using a damn micro Bluetooth speaker in my luxury suv for over 2 months now...pretty pathetic, ha!

[Chilled]

Does this help?

If your looking at the fibre network, can you see anything on the RX fibre? If it's receiving single, it will be lit.

Are you getting any error codes( not iDrive, actual code reader/ista).

[virtualbong]

Originally Posted by Chilled

Does this help?

If your looking at the fibre network, can you see anything on the RX fibre? If it's receiving single, it will be lit.

Are you getting any error codes( not iDrive, actual code reader/ista).

I do not receive any error codes at least on my display. I guess I could use an OBD II reader to see if it captured anything but nothing apparent right now.

From what I can remember, I could see the lights flashing consistently for the Bluetooth and Amplifier. What I need to check is whether or not the amplifier is solid yellow or flashing. I guess if it is flashing yellow then the module after the Amplifier is bad based on this video (

)

Where is the Comm box?

[Chilled]

Light wise, I was talking about the fibre network. The two fibre cables, one is for Receive (RX), the other is for transmit (TX).

If the issue is upstream, the RX fibre wont be lit up. Stick in front of the RX cable and you will see a red light. Don't look into it.

[virtualbong]

Originally Posted by Chilled

Light wise, I was talking about the fibre network. The two fibre cables, one is for Receive (RX), the other is for transmit (TX).

If the issue is upstream, the RX fibre wont be lit up. Stick in front of the RX cable and you will see a red light. Don't look into it.

I confirmed that the light going into the amplifier is lit up and then the amplifier is solid yellow which I believe means that the module after the amplifier should be good? I also see a red light next to the yellow light inside the amplifier...is that just showing that the red optical light is working or is this a sign of an issue?

[virtualbong]

Bringing this to the top. Anyone have an answer to my previous post?

[virtualbong]

Still need assistance. I just purchased a replacement stock Harmon Kardos amplifier from a 2016 F15 but it didn’t resolve the sound issue. Does anyone know if I need to get it coded to the car?

[RED_Y_]

I don't think so since bav sound sold their amplifiers for F15, as far as I know these are plug n play, no coding needed.

[virtualbong]

Originally Posted by RED_Y_

I don't think so since bav sound sold their amplifiers for F15, as far as I know these are plug n play, no coding needed.

If that is the case then I am thinking I may have a bad head unit. Anyone have any recommendations on how to confirm that the head unit is the issue?

[Chilled]

You mentioned that you were going to get a code reader. Did you end up doing that, maybe point ISTA at it and see if it can see all the components. It also has a wiring diagrams if you need to start diagnosing individual pins.

Not recommending, to rule out the fibre loop. Disconnect it from the amp and put the car into ACC. You should get a bunch of errors ranging from your gauge cluster to your HU.

You will need a code reader/ISTA to clear the codes after this.

[virtualbong]

Originally Posted by Chilled

You mentioned that you were going to get a code reader. Did you end up doing that, maybe point ISTA at it and see if it can see all the components. It also has a wiring diagrams if you need to start diagnosing individual pins.

Not recommending, to rule out the fibre loop. Disconnect it from the amp and put the car into ACC. You should get a bunch of errors ranging from your gauge cluster to your HU.

You will need a code reader/ISTA to clear the codes after this.

I actually didn't think about getting a code reader. When the amp is disconnected, the only apparent warning I get on the screen is "No warning tones". At least that is what I remember when I disconnected the amp. When I reconnect, everything works and there are no error codes.

[Chilled]

Get yourself a Enet Cable/Wifi adapter and a copy of ISTA. Without it/a code reader, you'll be more or less blindly guessing.