TARDIS matrix

A TARDIS matrix was the soul/consciousness of a TARDIS, its very sentience.

Deleting a TARDIS matrix would mean blowing a hole in the universe. It could, however, be removed from a TARDIS and placed into a recepticle, which is what House did when he brought TARDISes into the bubble universe. The matrix would eventually die, and without it House could feed on the residual artron energy of the TARDIS. The Eleventh Doctor's TARDIS matrix was placed inside Idris, possibly extinguishing her own consciousness. This actually allowed the Doctor to communicate with his own ship for the first time before Idris' body finally collapsed and the matrix returned to the TARDIS. (TV: The Doctor's Wife)

Matriz de la TARDIS