I would be very grateful for any advice anyone can provide on a problem with the MMI on my Audi A6 Avant 2.0 TDI 2007 Model (Chassis Type 4F0) (MMI version: colour screen, Bose Surround Sound, Radio, Navigation, 6 stack CD Changer, telephone).

The radio stations on the MMI started to drop off along with the reception. Suspecting the Aerial Amp (R24), I removed the FM coax cables from either side of the amp, connected them together and reception improved a little. So good, so far. I then went on to check the 12v power supply to the amp and carelessly allowed the contacts to short (pins 30 to 31)!!! This blew the 5Amp fuse in the right hand rear compartment (listed as MMI Aerial Amplfier) which I replaced.

The MMI now does not come on and at best the MMI screen intermitently brights up and then goes off again. Therefore, no radio or anything - I suspect this will be an expensive mistake!!!.

Diagnostics conducted as follows

1. I have tried the MMI reset (pressing setup, middle **** and top right control button) to no avail.
2. I have checked all the fuses and found no further failures.
3. I ran my VAG COM diagnostics. Editing to the relevant, this reported:

07-Control Head -- Status: Cannot be reached 1100
0E-Media Player 1 -- Status: Cannot be reached 1100
19-CAN Gateway -- Status: Malfunction 0010
37-Navigation -- Status: Cannot be reached 1100
47-Sound System -- Status: Cannot be reached 1100
56-Radio -- Status: Cannot be reached 1100

4. I interrogated the CAN gateway with the following which I assume corresponds to the self induced short:

Address 19: CAN Gateway Labels: 4F0-910-468.lbl
Control Module Part Number: 4F0 910 468 A HW: 4F0 907 468 D
Component and/or Version: Gateway H11 0070
Software Coding: 6CEE53C51B3104
Work Shop Code: WSC 02334 758 00200
VCID: 2759FFAFEF7D
1 Fault Found:

00384 - Optical Databus
011 - Open Circuit
Freeze Frame:
Fault Status: 01101011
Fault Priority: 5
Fault Frequency: 1
Reset counter: 230
Mileage: 141421 km
Time Indication: 0
Date: 2014.01.04
Time: 15:33:24

5. I then ran the Optical Bus Diagnostics, results as follows:

Control Module Part Number: 4F0 910 468 A
Component and/or Version: Gateway H11 0070

Optical Bus Diagnostic : Standard

Controller Electrical Optical
19-CAN Gateway OK OK
07-Control Head(High/D3)OK OK
0E-Media Player 1 OK OK
47-Sound System ERROR ERROR
56-Radio ERROR ERROR

6. I have removed the amplifier J525 (4F0 035 223 G) which I assume corresponds to the sound system and the radio (4F0 035 541 L) and have them on my bench.


I would be very grateful for any advice on what I should do next to fix this sorry state, preferably without spending too much cash!

In advance, very many thanks.

Ivan S