GM Code Location

[TBK]

This would be dangerous in the GM ECM's.

TK
-----Original Message-----
From: Alexander Wenning <wenning.motorsport at t-online.de>
To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
Date: Monday, January 26, 1998 4:19 AM
Subject: Re: GM Code Location


>         The checksum for gm 165 ecm. The code calulates checksum of 0009
> thur 3FFF. If ya modify anything must recal total at 0006,7. Gm 730 ecm
code
> is similar
>
> Vance

I think it´s waste of time trying to find the checksum on all the different
chips. Maybe
GM does it the same way all the time but we´re busy with Bosch, Hitachi,
Siemens, Delco,
Weber Marelli and so on. It´s easier to modify the maps and find a suitable
place (no code,
no maps) to correct the checksum. E.g. if you´ve increased the values of a
map, go and find
a place next to your map where some $FF´s appear and decrease them until the
checksum of the
complete eprom is like the original one again.

Regards

Alex Wenning
wenning.motorsport at t-online.de