<html>
GM reference is VCM - A on '95 Centril Port config. ,Err
kinda , mostly OBD2.<br>
Even has 20 fuel trim Cells , 4 being Idle, supposedly not
OBD2 Monitored.<br>
Len<br>
<br>
<blockquote type=cite cite><font size=2>At this point there's no-body
doing this ??...I'm currently working on a programming</font><br>
<font size=2>method, but it'll be a while before I've got this one
figured out. This is one of the first</font><br>
<font size=2>truck "flash" computers.</font> <br>
<font size=2>Lyndon.</font> <br>
<blockquote type=cite cite><font face="arial" size=2><b>-----Original
Message-----</b><br>
<b>From: </b>Dr.Acacio
<<a href="mailto:aortiz@w3ti.com.br">aortiz@w3ti.com.br</a>><br>
<b>To: </b><a href="mailto:gmecm@diy-efi.org">gmecm@diy-efi.org</a>
<<a href="mailto:gmecm@diy-efi.org">gmecm@diy-efi.org</a>><br>
<b>Date: </b>September 14, 2000 9:41 AM<br>
<b>Subject: </b>SS10 Help<br>
<br>
Hi all </font><br>
<font face="arial" size=2>Could anyone give some helpto change the calibration for </font><br>
<font face="arial" size=2>a GM Truck SS10 95, with Delco black box<br>
16166340<br>
86BABBK 43212W P5<br>
service 16193495.<br>
<br>
Thanks in advance<br>
</font> <br>
<br>
<br>
<font face="arial" size=2>>Hi,<br>
> My best guess is: maybe, but you would have to try it. I am not too<br>
>confident.<br>
<br>
I would need to know what year the S-10 is from.<br>
<br>
You need to know that GM did not standardize their communication protocol. <br>
They made changes to the commands and responses nearly every model year. We<br>
found that the 93 LT-1 responses are quite different from the 94/95 LT-1<br>
responses. And of course the 96's are OBD-II. So this would imply that the<br>
S-10 might have a different communication protocol.<br>
<br>
You also need to know that if you go down the 'remove the flash' route,<br>
that GM has swapped some of the lines between the flash and the CPU. If I<br>
remember correctly, they swapped 3 of the address lines. So by simply reading<br>
the data in the flash, you will see garbage. It can be decoded, but again,<br>
that is more work.<br>
<br>
From what I've seen from the software inside a number of GM PCM's, they<br>
tend to re-use their code whenever possible. Sometimes they reuse the actual<br>
source code, and sometimes they just reuse the ideas and the code looks<br>
similar but different. Unfortunately the location in the flash where some<br>
specific code (like for the speed limit) moves around alot from PCM to PCM.<br>
<br>
Also unfortunately, the speed limit change you need is probably just 1 or 2<br>
bytes that need changing.<br>
<br>
We really only understand the 94/95 LT-1 PCM's in detail. There are people<br>
out there that understand the earlier models pretty well, and some that<br>
understand the later models pretty well. I'd suggest you look into the GMECM<br>
mailing list (found at diy-efy.org) or the DIY-EFI mailing list (same<br>
address). There are ALOT of experts there that might be able to answer your<br>
questions, and maybe even provide some tools to help. I have to believe that<br>
someone on this list has the code for the S-10 truck, and might be able to<br>
point you at the location in memory that needs to be changed.<br>
<br>
You can try our software and see if it works, but you would have to<br>
purchase a cable.<br>
<br>
Thanks for finding that error on the web page. We will go fix it.<br>
<br>
Dave @ carputing.com<br>
<br>
<br>
"Dr.Acacio" <<a href="mailto:aortiz@w3ti.com.br">aortiz@w3ti.com.br</a>> wrote:<br>
<br>
> --------------------------------------------- <br>
> Attachment: <br>
> MIME Type: multipart/alternative <br>
> --------------------------------------------- <br>
Could be possible to use your program ( PCMReader.exe)to read a Brazilian S-10<br>
truck which has no VIN number????<br>
Since you know the protocol to talk with the GM flash ECU there are any<br>
chances to develop an editor for Brazilans trucks?? I know you are involved in<br>
the OBD II version of the editor, and probably has no time do do others<br>
projects, but we need here any tool to remove the speed limit...<br>
Thanks in advanced....<br>
PS<br>
1.Another way to read would be removing the flash and read it in a<br>
programmer...<br>
Do you think that the speed limit routine will be completely different from<br>
each GM flash ECU type????<br>
2. There are an error in your web page, the total tamount to buy cable and<br>
software will be from 195 to US$295.00 not 245.00.....<br>
Regards.</font></blockquote></blockquote></html>