LT1 EFI Question/OBD II

[Mike Fahrion]

>     First of all, the 95 PCM is *NOT* a full OBDII implementation. It may
>have the ALDL connector (implemented late 95), and the flash memory, but
the
>data sensors/error states are OBDI.
>
>
>Is there any clues (easy to find) if something is full OBDII, or not..
>
>big snip


Yes - here's a pretty easy way, that (I think) always works...

In the coming days and weeks you should be able to find more comprehensive
info at www.obdii.com.

All OBDII vehicles must have the connector defined by SAE J1962.  The
connector can always be found within 3 feet of the driver, usually low on
the dash or behind the ashtray.  If your vehicle is pre-1996, it could have
the J1962 connector and not be OBDII.  Follow the rules below to know for
sure.

First, you have to have the J1962 connector.  This is a 16 pin, D shaped
connector, not the rectangular ALDL connector.

If the connector has pin 2, 7 or 10 then it is OBDII.
If the connector has a pin 2, but no pin 7 or pin 10 it uses the J1850 VPW
standard
If the connector  has pin 10, but no pin 2 or pin 7 it uses the J1850 PWM
standard
If the connector has a pin 7, but no pin 2 or pin 10 it uses the ISO 9141-2
standard

I don't think any pre 1996 LT1's were OBDII.  The 95 Fbodies and Impalla
SS's were not OBDII, although I think some of the Fbodies had the J1962
connector.

If anyone knows differently - please let me know.

-mike
mfahrion at bb-elec.com