It will either be siezed or not.
If you pull the lid off the yam, take the plugs out, put it in neutral (disconnect the batery first & all the other helath & safetry stuff
) - can you turn the flywheel by hand? Without the plugs in it should go round smoothly & should go round without lots of horrible grinding noises.
If it makes scary noises or feels incredibly rough to turn, a quick visual way of checking damage it to take off the inlet and / or exhaust manifolds - then you can shine a torch into the cylinder & see the damage (or not) first hand.
Not had the pleasure of a Yam autolube, but my old Suz had a flow sensor in the oil line that also brought it to a grinding halt if the pipe blocked or the pipe fell off the bottom of the tank. An empty tank would also "trip" it. Might be worth checking the sensor(s) & their wiring / connectors on the Yam as well. (is the tank level float still floating?)