Some ALDL questions

[FJB203 at aol.com]

>  I believe this diagram was submitted by George M. Daily.

And about six others, actually. :).  This is the exact schematic I shoved on
my website.  I think all of the caps I used were 1uf's or .1 ufs, feel free
to stop at http://members.aol.com/fjb203/index.htm and on the left side of
the menu I created, click on "GM ALDL".  I have the schematic with the
values, as well as all of the associated GM codes I could find.

>  2) Has anyone actually built this circuit/cable and tried it???

I built it, and attached it to the engine I have sitting on a moving dolly in
my garage (3.8L 1986 GM engine from a Buick LeSabre.  I haven't devised
software yet, I had received a copy about a month ago of a basic
hard-coded-to-com1: terminal that would work with the ALDL interface however
due to  my being a disorganized moron I can't find it on the hard disk.

>  3) Does it work with the 160baud CCC and the 8192baud P4 computers?

I believe its 160baud only, however I don't recall of that's a limitation to
the circuit or because of the software I was sent :)

>  4) What does the data output look like after it comes through?

The GM vehicles send padder codes between each error code.  I think its
12,12,12, then 12 <error code> 12, and repeats through all the error codes.
 Again, on my website the code transmission information is there.  This is a
combination of what I've leached from various websites relating to ALDL as
well as what I've gotten out of Chilton manuals.  Personally, I haven't
gotten this far... still have the engine sitting on a moving dolly.

>  I am trying to build this so that I may diagnose my 1987 Buick Park
>  Avenue. (Picked it up for $550.00)  Unfortunately I don't have enough
>  money to afford the Diacom package.

Good deal :) :) :).  Side comment to George M. Dailey - SEE, I'm not the only
bargain hunter <G>.

Frederic Breitwieser
Homebrew Automotive Mailing List
http://members.aol.com/fjb203/index.htm