What is EEPROM?
EEPROM (pronounced e-prom) stands for Electrically Erasable Programmable Read-Only Memory and is a type of non-volatile memory used inMMI’s mother board to permanently store details.Normally the content of this memory can only be modified by Audi
Where is EEPROM on MMI unit?
The chip is manufactured by Atmel specifically for Automotive industry as a 2-Wire EEPROM. It has a capacity of 64Kb. The full part number is AT24C64A-10TQ-2.7 but it’s labelled as Q3, A, AT64A. You can find more information about the chip here (click)
How to read and write?
You can read and write to the chip directly using an EEPROM programmer. You can find them on eBay for $30 but you have to remove the chip from the board in order to do that. if you’re not very familiar with electronics and removing micro components… this is not an option for you. Alternatively you can use OBD-II port to access module 5F, login as an engineer with appropriate pin number, Send Seed and Access Key and read and write to the EEPROM. VCDS, VAS and other known cables will not do this job… you need a special cable and software to perform this.
EEPROM known content:
The EEPROM in MMI only uses 8192 bytes of the chip, when opening the content with HexEditor such as XVI32 it looks like this:
The EEPROM holds a list of languages that can be permitted to be install during firmware update, the NAR (North American Region) units only have English, Spanish and French. Whilst European unit shave English GB, German, Dutch, French, Spanish, Italian, Portuguese, Russian, Turkish, Swedish etc.. This section is better illustrated with a screenshot, please see below:
US \ NAR:
If you need to install languages, you have to modify EEPROM first and then then re-apply the appropriate firmware files. The language setup is introduced by EEPROM, referenced by root-ifs.ifs file on the flash and the actual language files are saved on the hard drive.
As part of the security and anti-theft strategy, VW has introduced a cool way to protect its clients. They have implemented the so called “component protection”. This is a mechanism dedicated to prevent exchange of modules between different vehicles without central authorization from the VAG online database. In MMI the component protection is save between 0x0640 and 0x0770, please see below:
You can transfer / duplicate / remove this section between all different MMI 3G and MMI 3G Plus units. When you upgrade MMI 3G to 3G plus this is the section that you will need to transfer. As of this minute (when typing this documents) there isn’t an easy way to translate or generate the above code. It’s not based on VIN only, it’s also based on several other variables that get pulled from CAN gateway.
Firmware details are located on 0x910 between pos 2314 and 2332
A lot of other configurations are encoded in none human readable format unfortunately are saved on address 0x0B00 between 2823 and 6540.
Credits: Keldo Gliana