How hard is it to reprogram PCMs?

[ChronoGN]

I have a 97 Camaro and since they dont make any reprogrammer for my PCM, I thought maybe I can make my own for my Computer Science project. And I was wondering how hard it would be?
Is there any website I can get info on reprogramming PCMs)? How much data are in the ROM? I have some experiences with reprogramming ROMs and I'm pretty sure my teacher could help me with this.

[AllTheGoodNamesAreGone]

I did alot of reseach on this a long time ago.. I am a CS major and its looks like a major PITA..

You will first need a way to extract the code from the cars computer.. then modifiy it.. then reflash (reload) it.. (note: you probably know about flashing PROM chips (3rd gens had these) chips, cars no longer use proms, they use some form of flash memory I think..)

There are alot of good sites out there.. However this is difficult and potentialy bad for the car..

The problem I ran into at the end was figuring out what to change in the coding.. This is becuase their is not any really good editing software out their.. and I was not willing to use trial and error.. so I stoped my research..

just start sreaching google for keywords like obd2, obdii, PCM, reprogram, extraction.. ect ect..

Its definatly possible.. and i came across alot of "free" software to do it.. but I never acctualy decided to try it..

Let me know if you want to persue this more, i think i may still have the links i found on one of my 3 computers.. email me (see profile)..

Good Luck
~Billy

[jamie]

magnus is good at it. he has a forum up just for this type of thing. i believe its

http://www.dxsoftware/forum

i could be totally wrong the addy though

[ChronoGN]

All right, thanks, those are good start for me. I think I will make this my ComSci project.

[AllTheGoodNamesAreGone]

SWEET! I am glad to hear you are motovated to do it.. (I just kinda gave up)..

It would be cool if you kept everyone posted on the message board.. I know that I would be super interested in your findings..

I have a few things on my car that i would just like to "change" (ex. the error code that my exhaust throws) I know that if i was able to get to the source level I would be able to disable it.. but i never made it that far.. I never even really extracted it from the cars computer..

If you need anything let me know.. I have auto tap.. the software wont do you any good, but the hardware may be helpfull for extacting..

~Bill

AND here is the correct link to Magnus's site
http://pcm.dxsoftware.com/forum/
He knows what he is talking about.. However there are still some major walls to climb when atempting this project..

[ March 12, 2003: Message edited by: AllTheGoodNamesAreGone ]</p>

[malloynx#2]

just do what i did. i bought a used pcm for 50bucks from tacreations, made a list of everything i wanted done to the pcm and mail it to zooomer with a check for 300$..

next week i'll have no top speed limiter, 6500 rev limiter, cooling fans turned on earlier, etc..

also from what i have heard magnus cannot reprogram pcm's yet... this is what i heard, i might be wrong..

[Magnus]

THere is a TON of info regarding this on the pcm site, http://pcm.dxsoftware.com/forum/

I even have binaries of many of our cars posted up as well..

Currently my burner is not working. I STILL haven't sent it in for repairs. Even if it did work I'm not doing any cals because imho my method sucks. I hate it. It's too much burdon me. In my free time now I'm researching VPW protocols.

[AllTheGoodNamesAreGone]

magnus,

Just of of curiosity what was the big trouble with your method?

You were removing the flash chip from the pcm.. extarcing the code with that "thingy" (i dont remember the name).. then you are left with a binary file..

What happend with the binary file.. did you use any convertors? ever try writing your own?

then after you make your changes you, convert back to binary.. and reload onto the the flash chip??

I am trying to get a grip on how this all works, I am even thinking about persuing it again..

Other questions:
were you ever able to extract and reflash via the obdii port?
how do the ls1's achive this with ls1 edit??

I am curious to know.. and i am sure any info you are willing to share will also help out ChronoGN..

Thanks for beaing the coolest moderator ever..

~Bill

[Magnus]

The trouble with my method is removing the chip all the time. It gets tiresome. It's a PITA too. 44 small pins, very finicky.

emp-20 is my programmer.

I have many of the binary files posted on the pcm site. I modified a few for test but my method is hard to do trial and error.

I never convert from binary. All changes are made by manipulating the hex code. :(

Haven't done it via the OBD-II port though. Several members on the pcm site are working towards this.

Carputing designed the cable/software. Their cable has a working rs232-&gt;vpw converter that supports block transfer and 4x mode with a buffer large enough to handle the flash file packets.

Thanks for the compliment. [img]smile.gif[/img]

[Texas4ever]

Magnus rules...!!!
[img]graemlins/rofl.gif[/img] [img]graemlins/rofl.gif[/img] [img]graemlins/rofl.gif[/img]

[pgriffith]

<blockquote>quote:</font><hr>Originally posted by Magnus:
The trouble with my method is removing the chip all the time. It gets tiresome. It's a PITA too. 44 small pins, very finicky.

emp-20 is my programmer.

I have many of the binary files posted on the pcm site. I modified a few for test but my method is hard to do trial and error.

I never convert from binary. All changes are made by manipulating the hex code. :(

Haven't done it via the OBD-II port though. Several members on the pcm site are working towards this.

Carputing designed the cable/software. Their cable has a working rs232-&gt;vpw converter that supports block transfer and 4x mode with a buffer large enough to handle the flash file packets.

Thanks for the compliment. [img]smile.gif[/img] <hr></blockquote>

WHAT



I know computers, but what you said about programming our pcms makes no sense to me. Went right over my head. Your talking nerd talk and I cant understand.

Anyways great job creating the PCM site. I think im gonna start reading up so I can decypher the nerd talk.

[ March 15, 2003: Message edited by: pgriffith ]</p>