cardinalfan

Regarding your clogged sunroof drains, others have suggested using weedwhacker line, I couldn't get the line farther than 4 or 5 inches and I was too lazy to take the wheel liners out and try from the bottom. I used.a tablespoon Liquid Plumber in each corner and 3 cups of warm-hot (not boiling) water in each of the four corners. Drains cleared!!!

twooldr

dvs_dave, The power unit, 4E0907280A, for the MMI screen plus other stuff is under the carpeting on the passenger side like you said. The Telematic unit, 4E0035616, is under the carpet on the driver's side. Neither looked corroded but I ordered replacements for both since both may be fried. The scan showed "Centr. Electr. II" was no or low power. 280A is is II unit, J520. Will update when I get them replaced, one at a time, of course. Thank you for sharing your knowledge. That under carpet info is hard to find.

dvs_dave

Yes, the “Onboard power supply control unit 2 J520” (to give it its official name) is under the (LHD) passenger/right side footwell carpet. By virtue of its location, it’s much more susceptible to water damage.

ltooz_a6_a8_q7

this is what under the carpet passenger side.
Cheers,
Louis

Giovanni Giovino 6.0+6.0TT

Thank you Dave and Louis for the info, mentally noted for future needs.

ltooz_a6_a8_q7

GG,
Do you know or have any link to how to clear the roof drains? I can see the holes in the front, but how about the rear? Do I need to remove the liner from inside the car?

twooldr

The new power supply on the passenger side flooring made the screen come up for 10 seconds with the radio on then close. An improvement for sure.
I then replaced the MMI controller keyboard and restarted it with the 3 button restart. Everything came back up. Screen opened and I could change language and the select radio channels. Switched to CD and played a CD. Have not re-scanned it yet but will Sunday. Driving to Seattle tomorrow. Will update later but so far so good. Thank you all for your help. To those that get the screen up for a short time then closes I would replace the MMI control console. Does not need any programming. Just need to do the reset. Glad I had spares to try out. First one did not do anything.
MMI center console now lights up and performs as expected. I replaced the telematic unit but that did not change anything, Have a spare if needed. Will update after the weekend trip.

dvs_dave

Glad we could help you get it fixed. As you found out, the MMI coming to life and then quickly shutting off is classic failed/liquid damaged MMI controller board symptom.

For info, the OnStar/Telematic unit is not actually connected to the MMI system beyond a mute wire. It even has its own dedicated mic and loud speaker. This is because it was a safety device so has to remain fully functional off of its own internal battery without it having to rely on the vehicles media system for audio input/output.

AudiDad15

I'm have the same issue for a while now. I got a replacement power control module that was also flooded and it needs CP removed 😢

Shark_V8

yeah how did two oldr remove the CP?

I should have a new MMI Board and a used Cent Elec II module next week.
As discussed, I installed a used MMI keyboard - no change still dead, and mine was pristine condition.