1994 obd1.5? [Archive] - GrandAmGT.com Forum


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03-03-2004, 08:34 AM
I've been researching this for a while and haven't found a definitive answer, so here I go again.

I have a '94 that has the OBD I style connector (trapezoidal, or whatever shape that would be) but it doesn't have all three lines coming from the ECU to the connector so I can't read the codes using traditional methods.

Can anyone give me guidance on how to do this? Do places like AutoZone have the ability to read from the OBD 1.5 (as I have heard them called)? Or do I need to have a dealer do it?


03-03-2004, 10:05 AM
Hey, 94 is ODB-I, along with most 95's. Very late model 95's were ODB-II. What you are thinking of with the ODB 1.5 is with the 95's, they work off ODB-II functions, but they are still ODB-I. Any pre 96 is also read with a ODB-I scan tool.

03-03-2004, 11:39 AM
Thanks for the reply.

The only thing is since I don't have the 3 lines coming into the connector, you can neither jumper it so it'll spit out the codes nor use a typical OBD I reader. Of course the line that's missing is the one you would normally ground. Any ideas on what can be done to get the codes manually?


03-03-2004, 02:33 PM
All the ports on the data connetor wont be there. That style is ODB-I style, and usd on many differant cars. Unless you somehow got some cut or ripped.

03-03-2004, 03:10 PM
Yeah, unfortunately there are only two wires coming out and the scanners / jumper method need that 3rd wire (I think it's the B wire?)

In any case, I had previously confirmed this was "normal" for a 94, or at least SOME 94's, and it's not a situation where someone removed one to be sneaky. I think the discussion was over on 60degreev6 talking about how some of us have weirdo OBD setups. If you go to the following link you'll see that the code scanner doesn't work on 94 and up Grand Ams (at least not ALL of them):

They don't exlain WHY there's this blackhole between 94 and 95 where they don't make a tool that's KNOWN to work... just up to 93 and 96 and beyond since some 94's and 95's apparently had this going on.

Maybe it's time to just call the dealership and ask them to do a scan. I was hoping someone had heard of the exact deal before and had a sweet idea on how to get the codes. Thanks.