has anyone ever even thought about giving it a try. its pretty much beyond my skill level but Ive seen some of the work done on here and I know that there are a few nerds on here that could probably do some crazy things.

for instance "and please dont beat me with a stick" if some one could locate the address and write the corseponding scripts to allow for it to adapt to the rest of the ecu's primary function.(I.E the other things that rely on the fueling table.) you could switch are cars over to speed density. @!#$ you could probably use the 2.4's or the 2000 ecu for reference.

I mean I know its a pain in the ass to track down every thing and then learn the language. but I have a friend with a 240/sr20 who used his editor to track down his spark table, and was able to put in a 2 step on a stock board. all he has is a nismo style daughter board for the added code. and the guys making a killing. because apparently no one has it.

so other then the crazy amount of time figuring every thing out, could it be done. I mean @!#$ Id pay upwards of 5bills to send out my ecu and have it come back to me speed density. only problem would be having it interface with HPT for changes.




"boobs now with Riboflabin"

Hex editing..... thats OBD-1 speak........

although, if you knew your spark reference angle, you could have a 95 computer run your Eco................



Chris


'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08

Wouldn't it be cool if the auto manufacturers released source code and schematics for their ECUs after they stop making a car like a lot of software companies do, then we could develop our own microcontroller based platforms without too much trouble.


----------------------------
<<<<<2003 Sunfire Sedan>>>>>

I've got the hex files for a number of j-body ECU's, and I've decompiled them into the code-ish versions using some VERY expensive software...

First, locating the tables isn't all that hard, they are all in the same spot (stored one-after-another) in the .data section of the code. The first tough thing to figure out is what processor the ECU uses so you can find the tables by decompiling into machine code (ASM statements). After that you need to figure out what part of the code does what, you find the long table jumps to find where the start and end addresses of the table is.

The tough part is that you can't just edit the tables in the new ECU's and be done with it. You need to recalculate the checksum. The checksum is usually stored at the very bottom of the hex file. This is the value the ECU uses to run an internal memory check before it starts running.

The difficult part, is downloading the code. Since the new ECU's don't use a de-solderable EEPROM chip (at least not easily), you can't just pull the processor out and reflash the EEPROM. Everything inside the ECU (other than a couple choice items) are surface mount devices (SMD).

With the Eco ECU, I know that the processor is BGA (ball-grid-array), and is an unmarked processor (almost impossible to tell what or who it is). BGA's can't be desoldered unless you have a really really good reflow machine, and even if you manage to get it out, you'll have to stick it into a development board to reprogram it, then resolder it to the board. You get probably one chance to do this, so even if you manage to change the tables, if you want to do it again your screwed. The only way it would work is to download a custom firmware that opens up the programming port through the OBD/serial interface.

At that point, its almost more economical to do a brute force attack against the seed/key to figure out the algorithm and figure out how to download and reprogram the tables the same way GM does with the Tech-II.





4cyltuner.com - Information Source For 4 Cylinder Tuners
Buy stuff from CarCustoms Ebay! Won't be disappointed!

There are no markings on the processor? do you know who produces the ecu for GM? maybe some phone calls can atleast get you a manufacturer so you know what intruction sets you're dealing with when you decode it to asm? I hate surface mount

I know this might not work but could there be any way, if you could reprogram, of changing memory addresses or putting in jumps to route them to i/o ports and interface another micro from there that contains custom programming, tables, etc and kind of bypassing the regular tables?

Hopefully if this standalone you're working on pans out none of this will be much of a problem anymore... what chipset are you using for your ecu?


----------------------------
<<<<<2003 Sunfire Sedan>>>>>

Delphi makes it for GM, and they will NOT give any information about it. There are no markings for a reason, to prevent anybody from getting the code (mostly other manufacturers, not consumers).

Its not impossible to get the processor model, I do know who makes it, but the part number is not a valid part number (a lot of manufacturers do that on high volume boards to prevent people stealing circuits).

The chip that I'm using, right now, is a STMicro STR912FAW44.





4cyltuner.com - Information Source For 4 Cylinder Tuners
Buy stuff from CarCustoms Ebay! Won't be disappointed!

Nice chip I'm doing some development using an AVR32 right now and I thought that was fast but 96Mhz w/ single cycle inst. is awesome! Did you solder it onto a pcb and add pins so you can work with it through-hole style, like on a breadboard or something, or do you have some sort of development kit for these? How do you find it compared to other micros? I only have experience with the old Motorolla 68HC11 and this Atmel AVR32UC3B I'm using now.

I can see why they wouldn't want people stealing their technology, it's just a shame because it doesn't make things any easier for us.


----------------------------
<<<<<2003 Sunfire Sedan>>>>>

Its soldered to a PCB, I have a PCB manufacturer that can make very small traces with solder paste to make it easy to do hot air work. Its actually pretty easy to use, but that's due in part to the Keil compiler that I'm using (I think we paid about $5000 for it here at work). My other choice was an Atmel AT91SAM7A3, which I have a little experience with, but I find its a lot easier for the STR9.





4cyltuner.com - Information Source For 4 Cylinder Tuners
Buy stuff from CarCustoms Ebay! Won't be disappointed!

@!#$_YO, my little 27SF512 can do all the things the new fat one's can!


... Ron.. you have a program that lets you hex edit?.......OBDII ECM's............


Please, for me, come home!

Chris




'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08