'96 LT-1 ALDL data stream

[Jennifer Green & Scott Peitzsch]

>My 95 Lesabre had the 16 pin J1960 plug and was 8192 baud ALDL.
>Just didn't know they included the "legacy" interface with the OBD-II
>PCM (96 up) UNLESS because 96 was a transitional year (first year of
>true OBD-II across the board) they left the ALDL in for a failsafe or
>for dealerships that did not have OBD-II compliant machines. (like the
>old Tech 1)

I've actually seen MANY case where the legacy ALDL data pin was left
on pin 9 and the new Class II OBDII serial data was on pin 2 in '96 and
'97 GM vehicles.  The ones that I have firsthand experience using are
my '96 Impala SS, my '97 Grand Prix GTP and John LeBlanc's (of MBA for
all you LT1 guys) '96 Camaro.  On the '96 LT1 cars w/ the 4399 PCM, the
vast majority of the typical scantool data is still present in the ALDL
port serial stream.

-Scott