Diagnosis

Hello all,this may sound like a silly question but, I am just curious as I have never owned an EV before, how do you all diagnose an electric vehicle when you run into a problem with the computer, especially when you get a "yello wrench" error message. Is there some special computer that you all use to diagnose? Now I work in an automotive shop and all we work on is ICE's and I am aware of how to diagnose an ICE vehicle because they have computers in the cars to diagnose them properly. Is it the same as diagnosing an ICE?
Just curious! Thanks for everyone's time.

Lisa ~