I think you should pull the throttle body, it only takes a sec. Then use the test mode to get a better idea of what steps mean full open, full closed, etc.

Negative steps would be on the other side of a home position, which would not make sense in this case.

Since there is no encoder feedback on these, it must move all the way to one end first to get an idea of where it is... It does that when you key on. I think it will call that 0 steps, then go from there.

Don't quote me on that, but i think that should be right.