You mean I still haven't found Probably. From what I know, TARDIS' bond really strongly with their Time Lords pilots, and it kinda goes both ways. There's a stronger psychic bond between them, so without the Doctor, the TARDIS is probably a bit confused and sad.
It's really great like that. I've been all over this world and others, thanks to the TARDIS and my work, and every time I think I've seen it all something new pops up. Like this old box having more people in it than I ever saw before, for starters.