MMI ECU replacement
 

Hi all. My MMI Multimedia Interface Control Module ECU has been on the blink for a few months now and I’ve tried, to no avail, to find a replacement. Our sponsors have these HW items but not with the correct SW number.

HW 40035729
SW number 4E0910769P

I was wondering if anyone knew if the SW number has to be exactly the same, as none I’ve seen online are, some end in H or Q for example. I’m not sure if either or neither of these would work.

All the best. John

The only thing I can find is that part number 4E0910769P was replaced by part number 4E0910769PX. Can't find anything on what each variant has/does. There appears to have been several variants of this module in the D3, all of which have been superseded over the years to 4E0910769PX or 4E0910769QX.

It might be worth having a chat with Maria or one of the other team at A8parts, and see if they're willing to refund you if you get one from them and it doesn't work.

Cheers mate. Some more info to go on there. I did email our sponsors again, and Maria got straight back and they’ve got one. But it’s £250. I’m a tight wad, and don’t use the car so much just now; mostly it’s ok. So I’m not convinced replacing it will be the cure all.

So I’ll keep on the look out I think, cos online they seem to be cheaper. May even take a punt on one that’s SW is very similar.

Hi There,

I'm *STRUGGLING* with my MMI as per http://forum.a8parts.co.uk/showthread.php?t=16341

I thought it was the gateway, coding or some such, but it has taken me down QUITE a rabbit hole.

I just ordered up one from ebay for about £50, which is

HW - 4E0035729A - You have 400 at the front 4E0 is typically the d3 audi.
SW - 4E0 910 732

Looking at reversing camera retrofits they are quite often swapped out for the A model, which has a green FBAS connector on it - Mine was already an A

Mine had SW 4E0 910 730

However a lot on ebay are A6's with 4F0 software but the same model number. How convertible they are i'm not sure.

I *MAY* hit component protection which is a dealer job or trying to copy a chip across - The programmer is cheap, so i've one on order
https://www.dognmonkey.com/audi/how-...ection-cp.html

I'd also add i'm VERY new to this MMI journey and i've read a lot, my head is spinning a bit, so please check stuff first to verify for yourself!

Hi mate. I’ve ordered one from eBay too, and fear I may be descending down the very same EPROM, component protection rabbit hole!

The thing is I’ve used my car lots the last few days and it hasn’t put a foot wrong. Which leads me to think the cause could need more investigation. (I’m having audio drop outs) I’ve bought this, see attachment. Purportedly from an A8 with the FBAS.

I just don’t want to spend time and money and make it worse and then be stuck needing a trip to the stealers with a CP issue.

Well.....My issue was the buttons. Changed those and my MMI sprung back into life :D

However since i had the "new" head unit, i though i'd pop it in.....And well no music, speaker icon with a line through. The NAV voice did however work, so i'm guessing Component protection. And yes, a quick VCDS scan did show CP active!

I *THINK* there may be a different software version on the "new" head unit as i'm on 5570 looking at my old VCDS scans - I checked the coding and they WERE the same. Unsure if updating the software would unlock the CP or not.....But i've got the chip reader and i'm now curious, so will dump my rom and then transfer it to the new box and we'll see :)

Eek. I admire your perseverance. The more I thought about the issue the less I’ve been inclined to do anything about it. All I have is a click and a few seconds of silence.

I’ve got the ECU, but can’t be bothered with CP and S/W incompatibilities so it’s on the shelf for now.

I hope you get yours fixed 100%.

My dad's A6 had an issue with the radio randomly coming on. it did show as a fault with the MMI in VCDS (can't remember the fault code) but I was advised by the garage it was in to stick some WD40 down there. I let the car go to sleep and then sprayed some of the WD40 contact cleaner and it has never done it again.

Not the same problems you guys have had but worth a try if there is any liquid that has gone down there or maybe a dirty contact?

As for CP, I think some people may be able to do it remotely but not too sure

Oh my problem is fixed.....The buttons did that!

I've JUST managed to read the working firmware off my non CP working unit. Finding the right software/drivers for the programmer takes some doing and DAMN the holes are small for fitting the wires in - I had some fine multistrand stuff that i trimmed and made work, but even with a magnifier it took some doing!

Then the software is generally a bit bobbins, or maybe my wires or something. I could just about get a read in the first 10 seconds with most the software. I tried a couple of versions and a couple of different pieces of software. I've now got 5 identical files and you can read the serial number out, which matches with an old VCDS scan as well, so i'm pretty confident i've managed to back my eprom up. A WHOLE 8k file!!!

You need a fine T7 torq to get into the head unit itself and i think having the RIGHT size wire to start with would make it a fair bit easier, but in all honesty, it really isn't a job to do, unless you need to......Or you have an interest in it.

Updating the software won't remove CP. You need someone who has ODIS and a genuine Geko certificate to remove it.

Interesting! Is this unit all part of the buttons? Is the control unit under the buttons or a separate unit?

Reminds me of an issue many many years ago with a minicomputer system that was satellite (one of many) to a huge mainframe.
It was misbehaving and the engineers kept stripping it down and replacing various components as their diagnostics were not definitive, with no luck.
In the end I (onsite project manager) recall a conversation with the chief engineer who said "We've replaced every F******** part of this thing except the tin box and the console keypad!"

At which point I saw him have a "light bulb moment". :ROFL: And a few minutes later, having extracted a keypad from another system it was up and working.

Last night, on a roll i read the eeprom from the "new" unit and managed to get that to verify as identical a few times, so saved it. Just because!

Then I WROTE my HU firmware over it, read it back and verified what i'd written as being identical.

I put the new HU in the car and it was in GERMAN - It was late and i was hungry, so left it.

Just had a look and switched the menu language back to English and i was much happier. Still had CP....Got VCDS out to have a look and yep. CP still engaged.

HU was coded 000000 and i switched to 000002. The TV module had a fault code and i cleared that and sound came on!!!!
I cleared the CP fault on the head unit and it stayed gone.

I had to switch 08 in the HU adaption to 1 to get back the secret MMI menu back to get all the options i had enabled

SO RESULT!

YES.....reading your eeprom from your old HU and writing it to a different HU did work. It's an almighty faff dealing with small fiddly wires, reading/writing and so forth, but it IS possible!

I'm now going to switch back as my HU wasn't the problem this time and rebuild my glovebox :D

The Head Unit 07 in VCDS is in two parts basically, the module behind the glovebox (4E0 907 468 A) and the buttons (4E2 919 610 B) in the centre console. BOTH need to work for the MMI to show.

From reading on the net the general consensus seemed to be the buttons were just buttons and them being dead just meant the MMI would work, but you wouldn't be able to use the buttons to control it. THIS is wrong. Unplug the buttons and the MMI shows for a few secs and then turns off.

Which is why i bought a second-hand HU (4E0 907 468 A) and was preparing to defeat CP, but my new module didn't show either, so i bought some second-hand buttons (4E2 919 610 B) which the MMI popped back into life.
I had the kit and was curious if I could remove the CP on the HU module with the eeprom write hack and it WORKED!

Thanks for the explanation and good work!