Magneti Marelli Clusters - gmenounos/kw1281test GitHub Wiki

The GetSKC command will work with several VW/Audi clusters made by Magneti Marelli. However there are at least 2 different variants with different EEPROM sizes and starting addresses. If GetSKC returns an "Unsupported cluster version" error, you can attempt to determine the EEPROM type yourself by running the following 2 commands to see which one, if any, succeeds (replace "COM1" with the proper COM port used by your cable):

kw1281test.exe COM1 9600 17 DumpMarelliMem 3072 1024
kw1281test.exe COM1 9600 17 DumpMarelliMem 14336 2048

If GetSKC fails and either of the above commands succeeds, please Open an Issue and attach your kw1281test.log so that I can add support for your cluster.

8N1920980A M73 D04

kw1281test cannot currently read this Audi TT cluster's EEPROM. Based on a ROM disassembly, it looks like it supports the special command (block title $6C) that allows uploading a program to RAM and then executing it, which is how kw1281test reads the EEPROMs from the other MM clusters, but for some reason it reboots before the program is uploaded.

It's still possible to retrieve the SKC using a R270+ device, which uses the processor's Background Debug Mode to read the EEPROM and ROM.

Note that this is a risky procedure and you could destroy your cluster if something goes wrong. The author of this document is not responsible if you damage your cluster.

Most of the common R270+ devices are inexpensive and come with little-to-no documentation and software. Presumably they're clones of a much more expensive device. The R270+ device has generic ribbon cable and connector. Plug in the ribbon cable (blue wire on the left when viewed from above) and separate 5 wires from the cable:

  • Wire 1 - Blue
  • Wire 7 - Black
  • Wire 8 - White
  • Wire 19 - White
  • Wire 26 - Brown

Then twist wires 8 and 26 together as shown:

R270+ Wires

Strip a few mm of insulation from the end of each wire and tin the wire with a soldering iron and solder.

Then solder the 5 wires to the cluster circuit board as shown here:

R270+ Audi TT

Note that the wire colors in that photo do not match the color of R270+ wires. The actual colors and wire numbers are printed at the bottom of the photo.

Then plug the R270+ into a Windows PC and run the software.

R270+ Software

The first thing you need to do is to choose the proper MCU Type. There is a 5 character code written on the large Motorola chip that is near where you soldered the wires. The code on my chip was 4K91D. My R270+ software did not list this device but I was still able to read the EEPROM by choosing 3K91D, which was listed. Beware that in most cases you need to have an exact match or the software may be unable to read your EEPROM (best case) or destroy the cluster (worst case).

Then under "Memory", select "Eeprom".

To the right of that you'll see "8M", "4M" and "40M". None of those was selected by default in my software. I was unable to read the EEPROM unless I selected one of them. I chose "4M".

Then click the "Read" button. You will be asked "Do you check PIN State?" I think this just means, "Are you sure you soldered the right wires to the right place on the cluster's circuit board.

Then it will read and verify the EEPROM and allow you to save it to a file. If it doesn't save to a file automatically, click the "Save Binary File" button.

You can then inspect the binary file with a hex editor and locate the SKC using this method: https://github.com/gmenounos/kw1281test/issues/50#issuecomment-1770255129