This may be a stupid question, but I'll ask anyway. ABS warning light on my 94 GT came on recently, and I want to know if I can use my scan tool to plug into the ABS diagnostic port to pull trouble codes. Thanks.
You don't need a scan tool for ABS codes (these notes taken from some other site at some point in the past).
Under the hood, on the drivers side, there is an ABS test port. It is mounted directly in front of the big black power distribution box. It is red and virtually impossible to not see. It says anti lock test right on it.
Push the little black tab down and remove the red cover thing.
You will see a black connector thing that looks like a pyramid with three wires. With the IGNITION OFF, run a jumper wire (short piece of copper wire is fine or a paper clip works well) from 57 (black ground wire) to 836 (orange/white diagnostic circuit wire).
Leaving the jumper in place, get into the car with a piece of paper and a pen handy. Turn the key ON BUT DO NOT START.
Your ABS light will now flash the codes for you. They are two digit codes, so it will flash a few times, pause then flash again. So, for example, six flashes, a pause, then one flash = code 61. If there is more than one code, it will pause again (long pause) and flash the next code.