[Diy_efi] Chiptuning of Mercedes? VDO ECU

Magnus Gustavsson magnusgus
Wed Aug 16 15:00:50 UTC 2006

Hello to all on this fine forum, I finally think I have found some
competence! [image: Wink]

I have a Mercedes AMG C36 -94, that I want to tune for use with E85
Here in Sweden it has become very popular to run your car on this new,
powerful and cheaper +environmentally better fuel.
You can read more about this on: www.etanol.nu

My car (and some others) are able to adapt up the fuel amount (around +26%
extra compared to petrol)(all the way up to 100% E85 in the tank) by reading
the signal from the lambda-sond.
The problems are only that the optimum ignition kennfeld + coldstart
enrichments will not be changed too.

Therefore I have come to the conclusion that the best would be if you could
reprogram the eprom in the ECU to increase coldstart enrichments + alter the
ignintion curve (and on all other cars also rewrite the general fuel amount
since they are softwarevise not allowed to adapt fully to E85).
I'm pretty sure that once one engine is reprogrammed like this, all others
can be modified tha same way, without too much engine knowledge.
It could also be nice to be able to switch back to petrol settings if you go
on holiday in a not so well developed ethanol, country.. [image: Roll Eyes]

I have opened my ECU and found that the eprom (in a socket already!) is a
 TI  TMS27C210A-12JL.
This eprom is mounted in a VDO ECU that is used in many Mercedes and even
motorcycles (Ducati?) from the beginning of the 90-ties.

Unfortunately there seems be very little on the net about Mercedes, VDO and
Still, there are several places where tuned chips are availble, even for my
Does anybody have a clew from where these tuners get their info on defintion
files etc?
And can you please point me in the right direction for how to find out or
get usable definiton files for this ECU?
I've tried to search in this maillist a little tricky so I might have missed
something.. without success.


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