My mechanic considered putting a new Crank Shaft Sensor on to determine if the Check Eng Light goes off. He and the other guys in the shop pointed it out and I can complete this and I intend to do so. If the light's still on, I'll put the old sensor back on and go from there.
I didn't ask my mechanic, but if the new sensor is put on and this was the problem, would that cause the Check Eng Light to go off? I guess that's the objective, to confirm if it's in fact the sensor. Or if it's still on, then perhaps a System Variation Learn may not have been done.