Phil, I think the only way to find this out is to remove the shell or build a test rig so you can monitor the motor voltage as you watch the flashes. That would be the blue and yellow wires at the Molex micro fit connector on the motor driver board.
No idea if they are equal increments between zero and full voltage nor if every board is the same.
Even knowing this it has little bearing on actual speed due to gearing and driver diameters and loads in the case of non cruise engines.
As for the usefulness of monitoring flashes, I do this with all my Cruise engines, Odyssey and Back EMF. I want to make sure they start to move at the first flash (speed step). A sign everything is working right.
Pete
