'96 LT-1 ALDL data stream

[Andrew Mattei]

David Cooley wrote:
> Hmm..
> I didn't think there was ALDL anymore with OBD-II... According to the SAE
> pinouts of the connector, they don't show anything with ALDL, only the 3
> different versions of OBD-II (GM's PWM, Ford's VPW, and Chrysler/foreign
> auto ISO-9141-2)

A couple of years ago Tom Hussey sent me a DOS based program that he'd
written to extract stuff from his '97 PCM (VIN, DTC's, and some other
goodies). Some of the commands/parameters worked on my OBDI PCM, some
didn't (I don't think my IAT was really at 64000 degrees F).
Unfortunately, I lost the program (a few computers ago), but the point
is, I was using the same old MAX232 interface to the serial port to do
it, and he was using the same type interface. I don't know about 1996
cars, but 1995 GM F-bodies (Camaro Z28, Trans Am, etc) use the OBDII
connector (though they're OBDI), and they use Pin 9 for serial data. I
don't know if '96 uses this same pin or not (it's not a "standard" OBDII
pin, so it's a manufacturer optional pin).

FWIW,

Andrew (help us Obi-Tom Kenobi, you're our only hope... ;^) )