[s-cars] Differences in ECU's?

[Dave Ellis]

Just what I was thinking after reading your first post.  I've seen these 
types of decryption boards a few times on other Audis, and they must be 
removed for any other firmware to work.

If you're lucky there is a socket underneath the daughter board and you 
can just carefully pry it out before inserting the new MRC chips.  If 
not lucky and the daughter board is soldered into the PCB, then you'll 
need to de-solder the decryption board and re-solder in some sockets, or 
just directly solder the MRC chip into the PCB.

If this isn't the case, I'm sure you could just send the MRC chips back 
to Bob for him to check.  Alternatively, if you know of another willing 
lister in your area you could install the MRC chipset into their car and 
try starting it just to see if the chips are good (if the car's hardware 
doesn't match, eg - no RS2, then I wouldn't recommend running it much 
above idle, but as a simple test of the EPROMs and firmware on them it 
should be fine).

Bob will have an EPROM reader/writer most likely with which he can 
verify the integrity of the EPROMs themselves and the installed 
firmware.  If not, several others on this list also have EPROM writers 
with which we could check the integrity of the chips.  However only 
someone (like Bob) with a known good copy of the correct software will 
be able to check the integrity of the firmware written on the EPROMs.

-Dave



chris chambers wrote:
> Michael,
> 
> Who installed the MTM chips? Is one of them on top of
> another circuit board and then on top of the main board of the ECU?
> I'm gonna guess you have a decryption circuit underneath one
> of your chips.
> 
> It is quite common for some chip manufacturers to install a "daughter"
> to decrypt the code on their chip, and then encrypt the code on their
> chips. The chips are then mounted on this extra circuit some call a
> "daughter board"
> 
> Look at the pic at this link, it is of just such a chip.
> http://img.photobucket.com/albums/v48/chrisanjenn/Audi%20S4/7ac02504.jpg
> 
> If you have this you need to remove the "daughter board" and solder
> in a socket into the ECU where the "daughter board" was installed.
> 
> HTH
> Chris