The self test options vary slightly depending on what SP chip you have installed in your machine. Ron (r273) made a great "for rookies" Excel spreadsheet that is available in the downloads section (must be a contributing member to access that), which covers a number of different generations of SP chips and explains what the different setup options are. It's probably also been posted here in the S+ section or somewhere on the archive site if you don't want to or are unable to contribute to the site at this time. A search for "rookies" might turn it up.
If you tell me what SP chip you have in your machine, I'll be happy to post the PSR for it which lists what the different self test options are for your machine.