Diag connector 95 Pontiac

I have a 95 Pontiac and I wanted to dump the error codes on it to find out why the service light was on.
I went to the connector under the dash, and you're supposed to
be able to ground the 'Diag' pin at "B" to ground at "A" and it kicks the computer into a diag dump mode.
But I don't have a connector pin at "B"
Yep, it's the 6x2 connector. Yep, the vin codes all match correctly to let me know it's engine "M" for that year and it should have the 6x2 connector. But there's a TOTAL of 3 wires connected to the connector.
A black wire at "A", which I'm assuming is ground A tan (or light colored) wire at "M" A green (I think) wire at "I"
In all the documentation I can find, there were NEVER any wires in the 'lower row' in slots "H" to "L".
So... What gives? Any ideas? Ground should be fairly easy to trace out, but what are the other two wires, and why are then in the slots I found them at?
Mike
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I may be mistaken, but from what I recall, a '95 is OBDII, and you can't do anything with it without a scanner tool.
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"80 Knight" <80 snipped-for-privacy@rogers.com - Remove SPMASUCKS To

Mike,
If that car has the older "6X2" connector, then it is OBD1. HOWEVER, most GM OBDI cars post 1993 do NOT have the capability of code reading via the "Check Engine" light - you must use a scan tool to retrieve codes (the "B" cavity in the ALDL connector is empty).
On top of that, the 94~95 cars are kinda a hybrid - OBDI electrically (ALDL connector, etc.) but semi-OBDII as far as the data stream (codes similar to, but not exactly the same as, OBDII codes). My '94 Regal with a 3800 Series I is like that.
There are some '95s that ARE OBDII - the 3800 Series II and the 3.4 engines are 2 examples. The '95 3800 Series I engine is a hybrid OBDI as is the 3100, which is the engine you have..
The added used pins in the connector are for connection to the ABS computer and the E&C data line (radio, HVAC, etc.).
Regards, Bill Bowen Sacramento, CA
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Thanks for the details. After I posted, I found one online reference that there were some 95s that would not dump the codes, but no explanation as to why. What was throwing me was the fact that it used the 6x2 connector. Then the fact that it only had 3 wires to it, and other than ground and data, the 3rd wire to 'J' (I didn't realize that they skipped 'I') isn't documented ANYWHERE.
I'd love to make up my own interface to see what I can do. But about the only thing I can find out is that the baud rate is a 'custom' at 8192. I haven't been able to find specs or protocols.
Mike
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Mike, I feel sure 80Knight is correct. 95's had OBDII yet inside an OBDI connector, Scanners use a special connector wire for just this one year--at least that is the way it is on 95 Z28, Corvettes, etc with the LT1 engines. I feel like other95's were affected the same. s
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LT1
From what I've been able to dig up, 95's are a bastard year. They are 'beyond' OBDI in what they can do, sort of a pre-OBDII. They also do not have any manual dump mode. But they are not OBDII compliant. Almost as if they were an interim subset of OBDII used for development with the intent of finally ending up as OBDII compliant. That may explain why they work with OBDII tools if you have the wire converter. I'll lay odds that the OBDII spec either includes a 'version number' that determines the level of support, or does something similar to a 'valid function list' that is communicated between the tool and the vehicle when negotiations start.
Bill seemed to hit it pretty close to what I've been able to find out.
Now if I can just get some kind of spec... It's gotta be out there on the web somewhere.
Mike
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Try contacting Andy Whittaker: http://www.andywhittaker.com /
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Put into my favorites! I'll do a more detailed check today...
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