I believe it's part of the AllData system.. they purchase a subscription service for it from a place that basically has all of that in the system...

myself, I just whore around and pick up service manuals on PDF and have a copy of nissan's FAST program here so I can look up 99% of the stuff I need. if not, then I call a dealership and get the number.

Honestly, there's no real need for us to have the part number if we know what we need. just call the dealer and tell them and they'll get you the correct part- as long as you're clear on what part it is.

 

That's true, but I guess I'd use it more for when I'm working on my vehicle and I want a good diagram / exploded view. For some reason, I just work better with screens than books.

Thanks!