Hi I'm a newbie here in the UK and could do with some help.
The buttons on the centre console have stopped working. They are not dead as I can still do an mmi reset by pressing the combination but cannot select any individual button i.e. car, setup, phone, media, radio or volume etc. The radio still works and can be controlled by the steering wheel buttons.
What I have done so far:-
1. Checked all the fuses in the panel next to the driver door and in the boot(trunk if you're in the US)
2. Replaced the switch panel as I found one on ebay. Exactly the same fault so assume if not a button issue
3. Inspected the connectors - They all look clean
4. Plugged in VCDS - This is the fault code -
Address 5F: Information Electr. Labels: 4E0-035-6xx-5F.clb
Control Module Part Number: 8T2 035 652 N HW: 8T2 035 652 D
Component and/or Version: B-BN-EU H61 0191
Software Coding: 010101060005A1ED01002B0E000000030000
Work Shop Code: WSC 06335 000 00000
VCID: 41DF56E7B18E2DD260D-8014
2 Faults Found:

00658 - Control Head
004 - No Signal/Communication
Freeze Frame:
Fault Status: 01100100
Fault Priority: 5
Fault Frequency: 1
Reset counter: 137
Mileage: 174704 km
Time Indication: 0
Date: 2024.04.05
Time: 14:51:49

Freeze Frame:
Voltage: 13.90 V

03175 - Invalid Data Set
000 - -
Freeze Frame:
Fault Status: 01100000
Fault Priority: 2
Fault Frequency: 1
Reset counter: 137
Mileage: 174704 km
Time Indication: 0
Date: 2024.04.05
Time: 14:51:47

Freeze Frame:
Voltage: 13.90 V
5. Disconnected the battery for a couple of minutes in case it just reset. It didn't...
6. Tried reloading the MMI Software but none of the buttons work so cannot get anything to boot on the SD cards

I'm now at a loss on how to fix this. I cannot afford to take it to a garage. Any help would be greatly appreciated.

Thanks in advance

 

The three finger salute from the MMI controls to the J794 is implemented on dedicated backup lines, not the normal RS-232 communications.

"B-BN-EU"? What is that, MMI 3G Basic? Does the sw ver info say BNav?

The E380 in MMI 3G is not independently powered; all 7 wires to it are direct from the J794. Could be the wires, ring them out to ensure none are broken/shorted. The E380 wires go to the upper half of the quad block on the back of the J794. Could be the J794 has trashed. You say you've already tried replacing the E380 and no change (assume it was the same p/n rev).

 

Thanks smac770. I’ll have a go at looking at the wires. Is the j794 the head unit with the sd cards and cd player? I think it still works as I have discovered I can switch to satnav screen, radio , phone etc using voice commands. If I take the sd card out whilst on satnav screen it recognises the maps aren’t there which makes me think you are right and it’s just the wires to between the buttons and the head.

 

Yeah, the J794 is the 5F-information electronics unit, the MMI control module, in the dash with the disc and media slots. Says Audi multimedia. The J685 is the screen above, and E380 is the control panel on the center console.