Checking wheel speed sensors on 599

So, what is the best way (proper way) to check/test wheel speed sensors for a 599? I suspect that one of my sensors is bad and is the root of the Christmas tree that is on my dash.

I suddenly got manatino failure and CST failure warnings and the car went into slippery surface mode; I can't change modes. The shifting is really wonky, sometimes grabbing hard, sometimes slipping, and essentially never rev matching. There is one code that doesn't have a definition in the Leonardo. I didn't write the code down so I have forgotten. I will read it again and post the code later today.

Of course I am open to other suggestions as well. The idea of wheel speed sensor suddenly popped into my head after thinking about this for a few days.

 

Yes, I have that as well.

 

My scanner does not but my mechanic's does; I will have him isolate what wheel and do the work. If there was an easy way to find it, one I had the facilities to do, I would have done the diagnostic myself. I have a lift and pretty well stocked garage so I might have taken on the replacement as well. I am always game for a new project but without the correct scanner I will have him do the work. Unfortunately, he has been so backlogged I couldn't get in right away.

 

Already replaced. That is where I started.

 

Thank you.