Is the MMI control panel in the centre console, also the "Control Head" as reported by VCDS?

[rjsdavis]

Up until Friday, everything within the MMI system was working fine. On the very odd occasion, the lights within the MMI control panel in the centre console would not light up when the car was started, but re-starting the engine would always solve this. It would happen probably 2-3 times per year.

Last Friday, it happened again, and an engine restart fixed this and caused the control panel lights to come on. However, this time, whilst driving the car and during the journey, the lights in the control panel just went out, but this time, it caused the screen in the dashboard to turn off as well. Curiously, my phone was still connected to the system via Bluetooth, and it continued to stream and play music even though the MMI panel and screen were off, however, the volume was fixed and neither the volume button on the MMI control panel, or the steering wheel could alter the music volume. It appeared to me that the MMI control panel had just died there and then. Nothing had been changed, no MMI updates, nothing had been spilled on it, and there's no water ingress in the MMI stack in the boot - it's as dry as a bone in there. It just died.

During the rest of the day, engine restarts failed to make any difference, and the MMI control panel and screen has remained off ever since. I’ve done a full VCDS scan of the car, and the only faults showing are all MMI related, in that it simply says:

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

Worse, the car wasn't used again until the Sunday morning. Come Sunday morning, the car battery was as flat as a pancake and would not turn over or even unlock from the key remote. It's clear that the system remained on for about 36 hours and completely drained the battery flat. It was charged all day Sunday, and the car started and runs fine and has done ever since. As a precaution, as the MMI system was down, I disconnected the large cable connector from the amp in the boot at the top of the stack, and the car system now shuts down in just a few minutes, and there is now no battery drain (you'll see above, that I have had drain issues for months!). The one positive to come out of this, is that the part-battery drain I've been trying to diagnose for months, is definitely, and without doubt caused from within the MMI system. I now never have any battery warnings on the dash when I go to start the car, the spotlights and rear lights always now come on when you unlock the car in the evenings even if she's been sitting around for a day or two (this didn't happen if the car had been left for a while, as the battery was part-draining, as it was taking the best part of 2-2.5 hours to shut down).

All other systems are ok. I've become aware from research in the RossTech forums, that the MMI system optical bus is a big loop, with the CAN gateway as the starting point, going onto the control head, and then onto the individual MMI components finishing with the radio tuner and then coming back to the CAN gateway again. Given that the CAN gateway is reporting ok in the VCDS scan, does this automatically point to the Control Head as the culprit that is stopping the loop from going any further, as it is first in the "faulty" list and has taken out every other module in the loop that follows it? My gut feeling is that the control panel in the dash is the faulty unit anyway given what happened, and because it's actually faulty, then remained an open or live circuit after the car was shut down last Friday, causing the battery to drain - this all appears to be logical to me.

Therefore, my question is; is the MMI control panel in the centre panel of the car, also the “Control Head” as reported by VCDS?

Assuming that this is yes - I'll get onto getting a replacement control panel / control head asap. I'm watching one on eBay at the moment, and a quick question about compatibility... My car is a 2007 A6. On the control panel, the button below RADIO is MEDIA on mine. The one I'm watching has TV / CD on the button instead of MEDIA.

I don't mind this, but would it be reasonable to expect any compatibility issues between the two?

[Gunnark100]

No,control panel and head are two different units. Panel is connected to the head(behind glovebox)

[rjsdavis]

No,control panel and head are two different units. Panel is connected to the head(behind glovebox)

Thank you for this Gunnark

Do you mean behind the CD multiplayer in the glove box, or behind the whole glove box unit? I.e. you'd need to go in from the footwell and get in behind the glovebox from underneath?

Also, so if the control panel, and control head, are completely different units, what does the control panel report as when VCDS is doing a scan?

Many thanks

[Gunnark100]

Thank you for this Gunnark

Do you mean behind the CD multiplayer in the glove box, or behind the whole glove box unit? I.e. you'd need to go in from the footwell and get in behind the glovebox from underneath?

Also, so if the control panel, and control head, are completely different units, what does the control panel report as when VCDS is doing a scan?

Many thanks

You had mmi 2G high?! Behind means you need to remove glovebox, to get access to contol head, but test other modules first!

In vcds, control panel is sub module under head, but its not part of optical ring and yours is "down"!

[rjsdavis]

You had mmi 2G high?! Behind means you need to remove glovebox, to get access to contol head, but test other modules first!

In vcds, control panel is sub module under head, but its not part of optical ring and yours is "down"!

Ok, thanks. Yes, I have MMI 2G High.

I don't know what the Control Head actually looks like. Is it just some sort of black box hidden behind the glovebox - like a large relay or something?

Thank you for explaining that the control panel is a "sub module" under the control head. Do you know whether if the control panel is the faulty item in my system, that this would effectively turn off the control head from the optical ring? I don't have spares lying around to test - indeed the only way I can think of to test any other module at all, is to get another module and plug it in. I can't afford to buy a whole new system, and work through it module, by module, so surely logic dictates to start with the module that appeared to fail whilst I was actually driving the car?

What would you do if this was your car?

Many thanks

[Gunnark100]

Ok, thanks. Yes, I have MMI 2G High.

I don't know what the Control Head actually looks like. Is it just some sort of black box hidden behind the glovebox - like a large relay or something?

Thank you for explaining that the control panel is a "sub module" under the control head. Do you know whether if the control panel is the faulty item in my system, that this would effectively turn off the control head from the optical ring? I don't have spares lying around to test - indeed the only way I can think of to test any other module at all, is to get another module and plug it in. I can't afford to buy a whole new system, and work through it module, by module, so surely logic dictates to start with the module that appeared to fail whilst I was actually driving the car?

What would you do if this was your car?

Many thanks

If it was my car, i would get optical loop or taking optical connector to the bits, attaching ends together and testing all units one by one(no need to buy new units for this). After you find faulty unit(rest system will wake up), double check will it get power(to avoid idiotic situation)!

Not bad thread:
Audi MMI Problems Diagnostic - Audiworld

[Bigtimmy]

So here we are then, CH partly removed to find details as seen below. Part number is the same as yours.



The internet is my friend and I’ve found a similar CH which is a little newer, same part number, same model number, newer software etc, so it’ll directly replace what I’ve got once the component protection is removed ......correct? New unit details below




Sent from my iPhone using Tapatalk

[rjsdavis]

Looks about right to me...