ALDL

[sdbartho at cca.rockwell.com]

> A friend and I have been trying to come up with a way to capture the data 
> coming from the ALDL connector on GM cars.

What kind of GM car? Depending on the year, make, and model, the data rate
is quite different.

> We have the Diacom software from 
> Rinda Technologies but we want something simpler. We have found out how to 
> trigger the data flow by bridging the A-B terminals with different amounts of 
> resistance.

Is this what the Diacom does? I thought they sent out the proper ALDL mode
request commands to get the ECM to send back the data it wanted. 

3.9 k (factory test) mode is really pretty useless, but I haven't played
with 10k mode enough to know what kind of data this mode generates. I suspect
that the diagnostic pin is also a serial data input.  

I'm working on a similar project for the '91-'93 Syclone/Typhoon, but I 
haven't got it all working yet.


Dig
sdbartho at hwking.cca.rockwell.com