How to read DTC from 1994 Camaro

[paulherman]

I have a 1994 3.4L OHV Camaro. My "Service Engine" light comes on occasionally, and I would like to read the trouble code. The car has a 12 pin data link connector with wires connecting to pins A, B, G and M. The Chilton manual, and most info I find on the internet says I can read the stored trouble codes by shorting pins A and B, however that does not seem to work on this car. When the pins are shorted, and the ignition switch is turned to the "on" position, the "Service Engine" light comes on, but does not flash (same behavior as if the pins were not shorted).

Various sources say that some 1994 models are hybrid, either with OBD-I and a 16 pin connector, or OBD-II with a 12 pin connector. But I'm not finding any definitive information - just people who think they know what they are talking about.

I have an OBD-II code reader, but I'm not sure how I would go about trying to wire a cable to convert from the 12 to the 16 pin connector.

The local auto parts houses say just jump the pins on this car, and if that doesn't work they can't help me. Of course there is always the possibility that the ECM is just bad, but the car runs good, and other than the inability to read codes, there doesn't seem to be any problem.

Hopefully there is an EXPERIENCED GM mechanic on this forum who can help me out, without just guessing at a solution.

Any assistance would be appreciated. If it helps, the VIN of the vehicle is 2G1FP22S1R2185955.

Paul

[Rob B (shoebox)]

You need an OBD-I scan tool or code reader.