Kev85

Hello!
I have a problem with my sound system
Audi A6 2.5 2005 year model
MMI Basic Plus
The radio / MMI / CD works but i get no sound from the speakers.

Sometimes when i start the MMI the screen lights up and then goes black and starts again.
I can play cds, i can see the seconds go up.

I have read a bit about the MOST Bus.
I disconnected the optical cable going to the amp
When i turn the ignition on i can see a red light from the optical cable but after a couple of seconds it flashes and then goes out.

Is the red light supposed to light up all the time?
I suspect that their might be a glitch in the optics so thats why it flashes and then goes out. What i have read so far is that the amplifier is the last unit in the ring?
So the next step i thought would be to disconnect CD changer and see how the optics behave when it is disconnected.

This fault has been for 2 years, the workshop hasnt been able to find the problem.
Kind regards
Kevin

SchwarzS6

The MOST system is a loop. It must be completed in order to function. My guess is that the system sensed that the MOST loop was not complete when you did this test and then shut down.

If you want to disconnect the CD player from the MOST loop you need a bypass connector so that the MOST loop remains a loop.

My suggested is to get a VAG-COM system. It has the functionality to test the MOST loop. If you go to the RossTech site (Ross-Tech: VCDS Tour: Optical Bus Diagnostics) they have some diagnostic tests for the MOST loop. The VAG-COM will also let you output a tone to each of the speakers in the system individually.

If your workshop does not have a VAG-COM or equivalent, find a new shop. If you plan to purchase a VAG-COM yourself make sure that you purchase one from Ross-Tech. The cheap ones you see on eBay will not be able to perform these diagnostics.

Kev85

Optical test:
Optical Bus Diagnostic : Standard


Controller Electrical Optical
19-CAN Gateway OK OK
07-Control Head(Std Plus) OK OK
0E-Media Player 1 ERROR ERROR
47-Sound System OK OK
56-Radio ERROR ERROR


Adress Autoscan
Address 07: Control Head Labels: Redir Fail!
Part No SW: 4F0 910 729 J HW: 4F0 035 729 D
Component: MMI Cockpit H35 0040
Revision: C51100DE Serial number: AUZ6Z3E1BD1022
Coding: 0000000
Shop #: WSC 00000 000 00000
VCID: 306B14F3D8E3


Part No: 4F0 910 609 B
Component: Bedienteil MMIC6H07 0010


3 Faults Found:
01042 - Control Module; Not Coded
000 - -
Freeze Frame:
Fault Status: 01100000
Fault Priority: 7
Fault Frequency: 254
Time Indication: 0


02084 - Component Protection
005 - No or Incorrect Basic Setting / Adaptation
Freeze Frame:
Fault Status: 01100101
Fault Priority: 5
Fault Frequency: 254
Mileage: 176664 km
Time Indication: 0
Date: 2015.09.23
Time: 00:17:58


02095 - Component Protection Active
000 - -
Freeze Frame:
Fault Status: 01100000
Fault Priority: 5
Fault Frequency: 1
Mileage: 179599 km
Time Indication: 0
Date: 2015.12.02
Time: 17:20:28
_______________________________________


Address 0E: Media Player 1 Labels: Redir Fail!
Part No SW: 4F0 910 729 J HW: 4F0 035 729 D
Component: MMI Cockpit H35 0040
Revision: C51100DE Serial number: AUZ6Z3E1BD1022
Coding: 0000000
Shop #: WSC 00000 000 00000
VCID: 306B14F3D8E3


No fault code found.

____________________________
Address 19: CAN Gateway Labels: 4F0-910-468.lbl
Part No SW: 4F0 910 468 A HW: 4F0 907 468 B
Component: Gateway H09 0030
Revision: 09 Serial number: 0800804C110039
Coding: 6DEE73C41B0104
Shop #: WSC 02325 785 00200
VCID: 2759FFAFED2D


2 Faults Found:
00384 - Optical Databus
011 - Open Circuit - Intermittent
Freeze Frame:
Fault Status: 00101011
Fault Priority: 5
Fault Frequency: 1
Reset counter: 231
Mileage: 178941 km
Time Indication: 0
Date: 2015.11.20
Time: 10:02:38


02095 - Component Protection Active
000 - -
Freeze Frame:
Fault Status: 01100000
Fault Priority: 1
Fault Frequency: 20
Reset counter: 208
Mileage: 178979 km
Time Indication: 0
Date: 2015.11.21
Time: 19:31:06
__________________________________
Address 47: Sound System Labels: 4F0-910-223-AS.lbl
Part No SW: 4F0 910 223 B HW: 4F0 035 223
Component: Amp.-ASK H09 0270
Revision: 16S00001 Serial number: 01512040055593
Coding: 0000004
Shop #: WSC 02335 785 00200
VCID: 1D35DD47BF71


No fault code found.

_______________________________
Address 56: Radio Labels: Redir Fail!
Part No SW: 4F0 910 729 J HW: 4F0 035 729 D
Component: MMI Cockpit H35 0040
Revision: C51100DE Serial number: AUZ6Z3E1BD1022
Coding: 0000000
Shop #: WSC 00000 000 00000
VCID: 306B14F3D8E3


No fault code found.
__________________________

What do you think?

SchwarzS6

I am not an expert on this but here are my thoughts.

1. The intermittent fault on the optical data bus is probably from when you did your test with the optical cable disconnected. You can ignore this error for now.

2. The other problems appear to be component protection errors. This usually happens when the components have been swapped in from another car. It is then necessary to go to the dealer and have them remove the component protection. This can only be done by the dealer.

Kev85

I have tried to reset errors but the optical and electrical errors on the cd player and the radio are still there.
Can the faults on the control head cause the errors on the units above?
It feels like even though i need to go to the dealers to erase the component protection i have a problem with one of the units.
The dealer could not code or erase the component protection last time i was there.

Serag Kamal

I had a similar issue and all I had to do was replace the Digital Tuner fuse in the trunk. I would suggest that and running a Optical Bus Diagnostic and see if that makes a difference.

Kev85

The radio/media player was replaced. Location in the glovebox.
After this the comp protection alarms got reset by the workshop and now it works.
Thank you for all replies