Add FBAS To MMI Head Unit 4E0 035 729

I helped someone to install FBAS on his 4E0 035 729 – 8/17/2016

2013-06-07 Parts needed to add to the board – 4E0 035 729 to make 4E0 035 729 A.

All parts should be size 0603 – SMD

Capacitors = 7 x 100 nF, 6 x 47 nF, 1 x 10 pF,  1 x 47 pF, 1 x 1 nF.

Capacitors electrolytic = Size 1 – 1 x 10uF, Size 2 – 1 x 100 uF. The surface mount pads are almost the same distance as the diameter.

size 1 pad

Resistors = 1 x 56 ohms, 3 x 0 ohms (can be shorts), 1 x 22 ohms, 3 x 100 ohms, 2 x 1000 ohms,  size 0805 or 1206 1 x 680K (680,000) ohms.

Crystal = 24.576 Mhz SMD or through hole.

SAF7113 = 9 bit video.

Fakra “E” connector (GREEN).

I still have one extra set of these – email me if you’re interested – $30 + shipping (US only) if in Europe contact Kris at VNSMedia to buy.

All Audi A8 from 04-06 don’t have RVC camera as an option. Unless the car has the TV or DVD options, the MMI Head Unit may not have the FBAS for the video input from the Camera. This Head Unit part number for A8 is 4E0 035 729 without FBAS, with FBAS, the part number will have “A” in the end 4E0 035 729 A.

I’m pursuing the RVC (rear view camera) retrofit for my 06 A8, my Head Unit doesn’t have an A, it’s missing FBAS circuit which I have to add for video receiving input. There is a company in Poland that offer to add the whole circuit for a fee, we just have to send the box over to them and wait to receive it back. We can also buy a unit that’s from another car, but the problem is that we will have to take it to the dealer to remove “component protection” because every car is built with specific components to specific id number. When we change something, we need to notify the “mother ship” = Audi center. Therefore, if we modify the existing circuit, we won’t have “CP (component protection)”.

According the expert in Poland, to add a workable circuit for FBAS, we will need all the components on the picture. It’s hard to see what size of components we need on the pictures, but all CAPACITORS & RESISTORS use size 603 SMD. The can electrolytic capacitor use size 1 (10uF) and size 2 (100uF) surface mount.

All these components are designed into support SAF7113H.

SAF7113H design

added FBAS      Original FBAS

Parts readily available in the US are all components except 2 that I have to order for China – The 9-bit video processor SAF7113H and the Fakra male connector “E”. I also ordered 5M Fakra cable from China, but many people order from Kufatec in Germany which is custom made for specific cars like Audi.

If you are in Silicon Valley, sells everything we need for this project – capacitors are $.02-.04 – resistors $.06-.08. 24.576MHz crystal (metal surface mount) = $.87. The cost of retrofitting this board is $15 for SAF7113H from China and $4. for the connector FAKRA. all others are less than $10.00. We do need T8 to remove the board from the case. Harbor freight sells a nice set for $8.

small tool set     T8 screws

The case will have to be drilled and sawed a part for the Fakra “E” connector  to go through.

prepare the case      T8 screws

prepare the case      T8 screws

parts on boards      finished

parts on boards      finished


  • My bigger concern is those 680k resistor. I got it in 0805 size, its thin film resistor. Looks different from original element(btw-what it exactly? Resistor too). Maybe in different package it has different reaction as LC equivalent? I will put rest of components on second unit to see difference. Sadly, cannot attach pics in comment

    • And to make things more interesting- based on your pics you just substitute inductor with really high resistor. Because it still see 1nf capacitor on board. But if you substitute LC part is not there shoyld be just a jumper instead of capacitor? Little weird to me to see only change of inductor to resistor

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.