Trying to pull 92 engine codes

I hooked that green single wire connector to ground and the check engine light just stayed on, what am I doing wrong or is the ecm not communicating? It's a 92 b2600i.

sounds like you have no codes,
did you disconnect the battery anytime before you tried pulling the codes?

They don't flash a no codes code, if that makes any sense. Like gm vehicles will flash a code 12 to let you know there are no codes and it is working. Mine the light just stayed on, doesn't flash or anything. Just seemed odd.

mazdas won't give you a "no code" code.
If ya didn't get a code more than likely you have to switch the wires underneath the dash for the "required maintenance"