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<DIV><FONT color=#0000ff face=Arial size=2><SPAN class=630304003-03092000>your
better off in the bank and performance to build your own :)</SPAN></FONT></DIV>
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<DIV align=left class=OutlookMessageHeader dir=ltr><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B> owner-gmecm@diy-efi.org
[mailto:owner-gmecm@diy-efi.org]<B>On Behalf Of </B>Dave Zug<BR><B>Sent:</B>
Sunday, September 03, 2000 2:14 AM<BR><B>To:</B>
gmecm@diy-efi.org<BR><B>Subject:</B> Re: ALDL data<BR><BR></DIV></FONT>
<DIV><FONT face=Arial size=2>If you have an o-scope and can see a square wave
signal between ground and one of the diag-terminals then you can be pretty
sure that its ALDL. If you can trap the signal and see if it repeats
then you can figger out about how many bytes are there. if its a really small
amount like 8 - 10 then there probably needs to be a request sent to the ECM
for it to start sending lengthy amounts of data, and the data being sent
without this request is very basic.</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>With a DMM, if using like a "John Fluke" 73,77,83
series DMM ($100- $150 range) you can see the voltage bar LCD points pulsing
up and down rapidly as the RMS DC value changes (as a result of the varying
duty cycling of the DC signal based on the characters being represented) in
some repeating pattern.</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>With an analog needle, you won't see much but a
steady DC voltage somewhere between 0 and 5, needle moving very very
slightly.</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>I think caddilac had an onboard diagnostic
viewing system built into the RADIO controls system??? Jeffrey M's wife
had a car with that system in it. You might ask him if it was a 95 and to
clarify my vague memory.</FONT></DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>P.S. .. anyone out there have flow numbers on a
complete stock TPI intake system, and Accel / Ligenfelter units?
;-)</FONT></DIV>
<DIV> </DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A href="mailto:jhaines@lingenfelter.com"
title=jhaines@lingenfelter.com>Jason R. Haines</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A href="mailto:gmecm@diy-efi.org"
title=gmecm@diy-efi.org>GMECM</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Saturday, September 02, 2000
12:22 PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> ALDL data</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>What is an easy way to check to see if an ALDL
port has any data coming from it at all (if it is wired correctly etc.)? I
have a custom car I want to read the data from but a Tech 1 and a Tech 2
won't communicate (neither will Diacom). Anything I can check with a
voltmeter? What about using the Diacom cable (parallel port) and some kind
of software to see the raw data (if any exists)? I think I might also have a
serial port ALDL cable (for some other software) that I could
use.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>BTW - the engine is a Cadillac Northstar engine
with a 1994 ECM (I think it is ECM part number 16197429) and a custom
harness (no Cadillac dash, no electronic throttle etc.).</FONT></DIV>
<DIV><FONT face=Arial size=2><BR>Jason</FONT></DIV>
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