ME7.1 / 24c04 on 2000 Audi A8 4D

[SundayNightDriver]

Hi everyone.
I own a 2000 Audi A8 4D2 (gas engine) with a ME 7.1 and what is apparently Immo3 (integrated into the instrument cluster).

I'm having problems unlocking the ECU in cold weather and I'm afraid I could be stranded pretty soon this winter. I currently cannot identify the problem.

Many people of the German A8 communities have problems with breaking cables, defective reading coils etc. so I am looking for a definitive solution for myself and the others.

I have a Laptop with a "dumb" OBD cable connected through an FTDI USB to RS232 adapter and Linux & Windows XP. It would be very helpful if someone could point at a method on how to use this to defeat the immo.

The ways to do this so far seem to be:
- Reading/flashing the 24c04. Would have to find the value for the immo and get an EPROM programmer with a clamp to access the EEPROM without desoldering.

- Dumping the firmware and changing the EEPROM values, correcting CRC, reflash and do a factory reset. So far I couldn't find the EEPROM values in the A4 dump I have. Is there any software available for dumping the firmware with XP?

- Lemmiwinks/Unisettings method: change values in RAM, then turn off ignition and let the ECU write the value back to the EEPROM. These programs could probably be patched to do that but I'm not sure I'll be able to do this. Commercial software likely also uses this method.

Any idea on where to start, preferably for the 3rd method? I'm willing to donate.

[melcool]

Hi I also own 2000 Audi A8 4D!:ridinghorse:but in our communities we have different problems like "SPARE PARTS" :)))) :bandit:
Your ""dumb" OBD cable connected through an FTDI USB to RS232" is not good for this job!I think that... as you know good english... if you stay a bit more on this great forum you will be able in :alberteinstein: relative short time to learn more about:viking: how and with what to do it yourself!

[SundayNightDriver]

Hm, I know of a Romanian member in one forum (who speaks German), maybe you'd like to discuss with him. Most parts are still available new here, and often cars are sold in parts since with Germany's labour prices, a large dent can mean the car is considered wrecked!

I know the cable isn't the best for this task, but it IS possible to write the EEPROM (or rather to the RAM addresses in the ECU that will be written back on shutdown) through the one I have.

Meanwhile, I have checked out some A4 EEPROMs to understand the CRC calculation which is fortunately straightforward. Now it would be good to have an A8 image, I would try to find the EEPROM part in it.

Flashing patched firmware is the one thing that definitely works now with my cable already..