Re: VR6 ECU

[Jean-Luc Trahan <jltrahan@gecko-electronic.com>]

Jayrham Chulani wrote:
> 
> Ok guys and gals.  I think I might have asked this question before but I
> have yet to get a definite answer.  Does anyone know hwere I can get some
> technical info about the BOSCH Motronic ECU on our cars?  I am
> specifically interested in finding some info about what kind of
> microcontroller and what size/speed/type of EEPROM they use.
> 
> TIA,
> --Jay
> 1996 Windsor Blue GLX
> Autotech Sport Tuned Exhaust
> K&N Filter minus Airbox Diffuser
> Curb Feelers 8-)

This post is mostly for the technically minded...

I do not remember off which Web site I took this info [it may be pure
smoke ;) ], but it seemed that VW (or their contract developper, BOSCH)
used Motorola's 68300 series 16-bit microcontroller.  Memory was
reported as being an 512K EPROM (SOLDERED, OF COURSE!!!)  Clock speed
was not mentioned, but in my experience as an electronics designer and
the quantity of information the MPU must process per unit time, I would
think that 25-33MHz is a real possibility.

Hacking the code for this application would not be "easy" like the older
MPU's since the code was most probably written in C, which, when
compiled, is a bit harder to reverse engineer that pure assembly
language (like I said at the beginning, this IS rather technical!!!) 
And with all this OBD II shit, the algorithms would be rather complex.

As for technical documentation, I think the best bet would be to have a
contact within BOSCH who doesn't care for his/her job if he/she gets
caught.  I have a friend that recently bought a manual published by
BOSCH for the F?rd/M?zd? 2.5L V6 used in the MX-6/Pr?b? cars.  He says
the manual (I haven't personally seen it yet) is great for learning
about the different techniques for fuel injection, air flow measurement,
etc. It is useful for somebody who wants to learn how to trick the ECU
in seeing different data from its sensors that may improve performance. 
However, it does not provide any real info on actual hack
implementations at the software/hardware level.  In other words, you are
still on your own.


- -- 
Jean-Luc Trahan
R&D Engineer
Gecko Electronique inc.
jltrahan@gecko-electronic.com