ECU files

[Charles Brooks]

Thanks for the info Dave. I'm going to try to import the PROM image into Excel and plot the whole thing. Hopefully I'll see at least some of the tables as repeating shapes. Come to think of it, CarPROM screen shots look kind of like that. The Arizona Speed and Marine site has a couple screen shots of CarPROM interpretations of PROM images. It looks like a simple graph of the entire PROM image. Does anybody on the list have CarPROM? Is that how it works?

Charles Brooks


---------- Original Message ----------------------------------
From: "David A. Cooley" <n5xmt at bellsouth.net>
Reply-To: diy_efi at efi332.eng.ohio-state.edu
Date: Mon, 14 Jun 1999 21:23:04 -0400

>At 09:08 PM 6/14/99 -0400, you wrote:
>Thanks Steve, I found it :)
>
>OK, assuming I'm able to identify a series of blocks as a table (Big
>assumption :)  How do I find out what type of table it is? i.e. VE fuel,
>acceleration enrichment, spark advance etc... ?
>

Usually by trial and error... modify a table and try it, monitor it with
Diacom or similar and see what changed.

>It looks like the data points in Promedit are scaled 0-255, is that for all
>tables or do some tables use a different scale? Would be totally wrong to
>assume that all the data points consist of three places? i.e. 001-255 (Or
>whatever the scale is)

All values in the chip (raw) go 0-255 (00-FF hex).  some are scaled to be
-127 to +127... very few actually mean what the number is raw in the chip
ie: a timing value in the chip may be AC hex, but would mean 35 in actual
timing degrees...  Each table has a formula associated with it, and each
ECM/PCM and cal may have different formulas for the same type of table.
Best bet is look at the .ecu file that comes with promedit and see how that
chip is laid out...  look at the tables, and look at them in the raw chip
image.  Most have a pattern that is recognizable.