The Doctor's TARDIS

The Doctor's TARDIS was an obsolete Mark I Type 40 TARDIS used by the Doctor as his primary means of transport. Capable, like all TARDISes, of travelling through space and time, the Doctor has travelled in his vessel from the beginning of time itself prior to the Big Bang (DW: Terminus, BBCR: Slipback) to the end of time itself (DW: Utopia).

Model and type
In his first incarnation, the Doctor implied that he had built his TARDIS himself. (DW: The Chase) It was later revealed that he had stolen it, although this did not necessarily preclude the notion that he had somehow been responsible for its creation (DW: The War Games, ST: The Exiles); it was clarified that, while the Doctor had not completely built the TARDIS, he had assembled multiple components of the control console in order to grant himself the ability to control the TARDIS without the necessity of a mental link with the ship, thus preventing him from leaving a signal that the Time Lords could track after he went on the run (EDA: The Taking of Planet 5). Marnal was the Time Lord who previously owned the TARDIS. (EDA: The Gallifrey Chronicles)

The Doctor's TARDIS was referred to by the Time Lords as being a Type 40. By the time of the Doctor's fourth incarnation, all Type 40s had been officially decommissioned and replaced by newer, improved models. All models except the Doctor's had been accounted for. (DW: The Deadly Assassin)

The Monk claimed to have a Mark IV TARDIS, while the Doctor had a Mark I. The Doctor vaguely suggested that the two "Marks" were fifty years apart, although he could have been referring to the age gap between the time differential between when he and the Monk had left Gallifrey, or the age gap between himself and the Monk. (DW: The Time Meddler)

The Master's dematerialisation circuit was a Mark II compared to the Doctor's Mark I. It was unclear whether this meant that the Master's TARDIS, as a whole, was a Mark II. (DW: Terror of the Autons)

Police box shape
Almost all TARDISes were able to blend in with their surroundings because of a mechanism called the "chameleon circuit", or "camouflage unit". On the one occasion on which the Doctor's was functioning, it appeared to automatically choose a form, although the circuit may not have been functioning properly even on this occasion. (DW: Attack of the Cybermen) Other, later models seemed to allow the pilot to choose a desired exterior. Both the Master and the Monk appeared to be able to program their chameleon circuits. (DW: The Time Meddler, DW: Logopolis, DW: Time-Flight) The Doctor showed Adric how the TARDIS could be changed to the shape of an Egyptian pyramid if the chameleon circuit had been working properly, implying that he theoretically could control what form the TARDIS would take (again, if the chameleon circuit were functioning). (DW: Logopolis)

In any case, the defining characteristic of the Doctor's TARDIS was that its chameleon circuit had broken after assuming the shape of a police box in 1963, London. It apparently had been working up until it landed in I.M. Foreman's junkyard, because the Doctor's granddaughter stated that the TARDIS had previously appeared as a sedan chair and an ionic column, and because both she and the Doctor expressed surprise that it had not changed form when they travelled back to 100,000 BC. (DW: An Unearthly Child)

Eventually, friends and enemies would be able to locate the TARDIS because it failed to change shape. The Daleks recognized the police box as the transport of their enemy (DW: Death to the Daleks), as would the Cybermen (DW: Earthshock) and the agent of the Black Guardian known as the Shadow. (DW: The Armageddon Factor) Captain Jack Harkness was on the look-out for "a version of" the police box throughout the 20th and early 21st centuries. (DW: Utopia)



The Doctor tried to permanently fix the problem of the faulty chameleon circuit, not wanting old enemies to have such an easy way to recognize him, by measuring its exterior dimensions in relation to an actual police box and then by visiting the Logopolitans to complete the Block Transfer Computations they would have used to fix the faulty circuit. Due to interference of the Master, he never completed this task. (DW: Logopolis)

In his sixth incarnation the Doctor thought he had succeeded. However the Chameleon circuit was still malfunctioning which became obvious when it appeared as first a cupboard, then a pipe-organ and a set of iron gates which did not fit in with their surroundings on Telos. It shortly reverted back to the old police box shape and broke down again. (DW: Attack of the Cybermen) The Doctor has made no further attempts to fix the faulty circuit and by his ninth incarnation admits that he is actually quite fond of its current shape.

When Donna Noble was briefly the DoctorDonna she began explaining how The Doctor could fix the chameleon circuit however her explanation was cut short as her mind started to burn.



Under the First Doctor, a faded St John Ambulance logo could be seen on the door. When the TARDIS regenerated itself at the start of the Eleventh Doctor's life, a new St John sticker was part of the door. (DW: The Eleventh Hour)

Lock and key
See also: TARDIS key



Entry to the Doctor's TARDIS was effected by inserting a key into the lock, just as would be expected from a real police box. However, the locking mechanism was anything but ordinary. It did not respond to police-issued keys, and indeed would not even open when unauthorized persons used the Doctor's keys. The Brigadier was prevented from opening the TARDIS in the Doctor's absence, because of the metabolism detector on the lock. (DW: Spearhead from Space) Nevertheless, there were occasions on which strangers were able to successfully use the Doctor's key, perhaps suggesting either a flaw in the metabolism detector or a sentient choice on the part of the TARDIS. (DW: Doctor Who (1996), DW: The War Machines, DW: Blink)



The external design of the key changed over time. As would be expected on a vintage police box, it primarily appeared to be an ordinary Yale lock key. (DW: The Dalek Invasion of Earth, Spearhead from Space, Black Orchid, Aliens of London, Father's Day, Blink) However, it did occasionally appear to have a more ornate, Gallifreyan motif. (DW: Planet of the Spiders, Robot, The Android Invasion, Ghost Light, Doctor Who)

The key could also be modified to track and locate the TARDIS, allowing the Doctor to find the TARDIS if it was within a hundred years of his position. (IDW: The Forgotten) On at least one occasion, the key expressed a link to the TARDIS by glowing and becoming extremely hot to the touch, acting as a signal that the TARDIS had recovered from shock and/or rebuilt itself, becoming fully functional again. (DW: Father's Day, DW: The Eleventh Hour) On another occasion, the key glowed when the TARDIS was about to rematerilaise. (DW: Aliens of London)

The lock could be manually secured from inside the TARDIS, preventing even authorised individuals from using the key to unlock the doors from the exterior. (DW: The Dalek Invasion of Earth, Utopia)

It was unclear whether the lock automatically secured from the exterior however. There were occasions on which the Doctor or his companions needed to use the key to lock the doors (DW: The Sensorites) but others (DW: Spearhead from Space, DW: The Christmas Invasion) in which the act of merely closing the doors locked the TARDIS. It was possible that the lock could be set secure either automatically or manually.

Despite the unique properties of the Doctor's TARDIS key, "master" keys did exist back on Gallifrey. These keys, under the control of the Castellan's office, could open any TARDIS, including the Doctor's. (DW: The Invasion of Time)

At one point, the Doctor installed a system that allowed him to lock the TARDIS remotely using a fob (as a joke, the TARDIS roof light flashed and a alarm chirp sound was heard, similar to that used on vehicles on Earth). He was also able to open the door remotely. (DW: The End of Time)

During the Tenth Doctor's first encounter with River Song, she remarked that she had witnessed his future selves open the doors of the TARDIS by snapping his fingers. The Doctor reacted with disbelief, but later successfully opened the doors in this exact fashion. After his regeneration into his eleventh self, and returning to Amy Pond house after being gone two years, the Eleventh Doctor opens the TARDIS, by snapping his fingers, although it looks like he is just showing off to Amy at this point (DW: The Eleventh Hour).

Periodically the TARDIS interior went through various metamorphoses, changing and altering, sometimes through choice or because of other reasons. Some of these changes were physical in nature (involving secondary control rooms, etc.) but it was also possible to change the interior design of the TARDIS as one would change the desktop theme on a computer; indeed the Doctor's fifth incarnation even used the term "desktop theme" to describe this (DW: Time Crash). The TARDIS was capable of doing this using a variation of the Chameleon Circuit. (REF: Doctor Who: The Visual Dictionary)

General Interior Appearance and Layout
Using the Architectural Configuration system, the Doctor was able to change and re-arrange the interior of his TARDIS with ease. (DW: Logopolis, Castrovalva, DWA: 2006 Doctor Who Annual) The Fifth Doctor also called this "change[ing] the desktop theme" (DW: Time Crash)



The TARDIS interior walls generally consisted of roundels; circular indentations that lined all of the TARDIS walls. Some roundels concealed TARDIS circuitry and devices (DW: The Wheel in Space, DW: Logopolis, DW: Castrovalva, DW: Arc of Infinity, DW: Terminus), while others function for viewing the outside. (DW: The Claws of Axos) The design of the roundels varied depending on where in the TARDIS they were; a basic circular cut-out with black background, roundels resembling washing-up bowls stuck to the wall, recessed wood paneling with a few decorative ones in what appeared to be stained glass, translucent illuminated discs or hexagonal shapes with nodes in the centre. (DW: The Hand of Fear)

Console or Control Room
There have been many variants of the Doctor's TARDIS main control room. They usually share common features such as a hexagonal control console, and a set of doors allowing access to the outside via the outer plasmic shell as well as to other rooms in the TARDIS and usually a scanner or some other means of observing the outside.



First version
When the interior of the TARDIS was first viewed by humans (Ian Chesterton and Barbara Wright) the console was a bright white room, with roundels on the walls with a large computer bank taking up a major part of the 'back' wall. These computer banks contain the fault locator along with various systems relating to navigational control and navigational piloting and plotting. (DW: An Unearthly Child, DW: The Daleks)

This console was removed by the Doctor in his third incarnation during his exile on Earth and remained in his laboratory. (DW: Inferno) The Doctor returned it to its old place later. (DW: Terror of the Autons)

The Doctor continued to rebuild the TARDIS console and the main interior of the TARDIS console room using "UNIT funds and equipment" throughout his exile as UNIT's scientific adviser. (DW: The Three Doctors)

The Doctor briefly changed the walls of the console room with what appeared like plastic furnishings appearing along the edges of the roundels. One of the roundels served as a replacement of the scanner, a picture appearing in its centre. (DW: The Time Monster) He later reverted to the more traditional design. (DW: The Three Doctors)

The Doctor rebuilt the console following its damage by Cyberguns. (DW: Earthshock) He later refurbished it completely, giving it a more sleek, high-tech appearance. (DW: The Five Doctors)

Second version
The whole TARDIS interior went through its most radical change seen following the TARDIS's entrapment inside the Doctor's family estate; the House of Lungbarrow (NA: Lungbarrow) the console had assumed a more Gothic, Victorian appearance, and included a library. Like the roof of an observatory or a planetarium, the ceiling of the control room "opened", revealing the Infinity Chamber which showed the outside and could display holographic images. The smaller scanner, which resembled an antique black and white television set, displayed other information. (DW: Doctor Who (1996))

Third version
See Edifice Following the TARDIS's destruction after it was caught in a dimensional tear (EDA: The Shadows of Avalon), it reconstructed itself into a massive bone-like structure that came to be known as the Edifice; its console room at this stage was apparently based on the console room at the time of destruction, but appeared to be made, like the rest of the ship, of bone, due to the TARDIS containing the Faction Paradox biodata virus that had infected the Third Doctor after his early regeneration(EDA: Interference: Book Two, The Ancestor Cell). This console room was 'destroyed' when the Doctor drained the Edifice of all its power in order to fire the ship's ancient weapon systems, forcing the universe to 'choose' realities and decide whether the Doctor remained himself or became a member of the Faction.

Fourth version
Having completed its regeneration on Earth after the Doctor was forced to exhaust its power in the destruction of Gallifrey, the TARDIS interior now resembled a mixture of the original console room and the Eighth Doctor's console room (EDA: Escape Velocity). The Control Room was now hexagonal and contains four alcoves, two on either side of the main doors and the interior door. One contained filing cabinets and chests, another lead to the library, the third contained a laboratory, and the fourth contained a kitchen (which looked out onto a English countryside vista and was an exact replica of the kitchen in the Doctor's house in Kent). This interior was destroyed when the Doctor was forced to use the TARDIS to contain the explosion of a cold fusion generator created by Marnal- the TARDIS's original owner-, presumably regenerating itself into the appearance of the next seen version of the console room (EDA: The Gallifrey Chronicles).

Fifth version


By the Doctor's ninth incarnation, the control room had been changed to its "Coral" theme, giving it a more organic design than the previous console rooms. (DW: Time Crash) It is believed to be regrowing itself after the massive damage it may have sustained during the cold fusion explosion, with the Doctor making do with anything for its controls and the TARDIS subsequently integrating them like the Extrapolator. (DW: The Runaway Bride) Hexagonal impressions on the walls had replaced the roundels, and the console itself incorporated many odds and ends ranging from a device resembling a bicycle pump to a mallet used for occasional percussive maintenance. (DW: Rose onwards) The console room consists of a circular room with a red tiled ramp leading from the doors to a hexagonal platform. On the hexagonal platform lies a second, circular, platform. The entire room was supported by six coral pillars that met with the top of the time rotor at the rooms ceiling. Under the main platform were storage areas large enough for the Doctor to enter (DW: Army of Ghosts), though some were packed to just below the top. (DW: The Unicorn and the Wasp)

Later, the console room was set on fire and at least one column destroyed by the violent regeneration of the Tenth into the Eleventh Doctor. (DW: The End of Time)

Sixth version


Due to the violent nature of the Tenth Doctor's regeneration and the resultant damage to the TARDIS, it required time to repair itself. After the ordeal involving the Atraxi attempting to recapture Prisoner Zero had been resolved, the Doctor returned to the TARDIS and, upon seeing the changes to the control room, immediately proceeded to take the TARDIS to the moon and back, in order to "run her in". Soon after taking Amy Pond on board for the first time, the new TARDIS console also provided the Doctor with a new sonic screwdriver, as the previous one had been destroyed.

Changes to the control room included a more hexagonal console, rather than the previous circular one and instruments resembling a typewriter, a telegraph, a gramophone, a set of hot and cold taps, and a view-screen made by Magpie Electricals. Each side of the console is centred around a different function (steering, fabrication, etc.) A larger, circular view screen is set into one of the walls. DW: Victory of the Daleks) There are fewer roundels on the walls, and an area located underneath the main console which houses the heart of the TARDIS and what appears to be an oily substance surrounding it.

It had at least three floors such as the lower section, the console room level and the second level, and several rooms, including a library and pool. (DW: The Eleventh Hour) It appears to be still wearing in as almost every time the Doctor has attempted to travel somewhere specific since its change, he has arrived late. (DW: The Eleventh Hour - 12 years), (DW: Victory of the Daleks - one month)

Secondary control room
There existed a small secondary control or console room which the Doctor claimed may have been the original console room. It was far simpler than the main control room, with the console resembling a desk, no visible time rotor and all the controls hidden behind what appeared to be wooden panelling. It had more subtle roundels, some of them framing stained glass windows. For a brief period in his fourth incarnation, the Doctor used this as the main control room. (DW: The Masque of Mandragora, DW: The Hand of Fear, DW: The Deadly Assassin, DW: The Robots of Death, DW: The Invisible Enemy) Presumably the Main control room had been added later in the Mark 1's life and was slightly or significantly more advanced than the original control room; which was subsequently downgraded to a Secondary Control Room.

Tertiary control room
There also existed a tertiary control room, which was cool and dark grey with a small mushroom shaped console. (NA: Nightshade, NA: Deceit)

Other control rooms
The Doctor has stated that the TARDIS has many control/console rooms. (IDW: Tesseract) Presumably through the Mark I's life before its retirement (and subsequent theft by The Doctor) several newer and more advanced control rooms were fitted.

Specific Control Systems
The TARDIS' controls were said to be isomorphic, that is, only the Doctor can operate them. (DW: Pyramids of Mars) However, various companions have been able to operate the TARDIS and even fly it. (DW: Castrovalva, DW: Four to Doomsday, DW: The Visitation, DW: The Five Doctors, DW: The Parting of the Ways, DW: The Sontaran Stratagem, DW: Journey's End) The Time Lords are also able to pilot the TARDIS by remote control, usually, as the Doctor once bitterly noted, so he may take care of "some dirty work they don't want to get their lily-white hands on." (DW: Colony in Space, DW: The Brain of Morbius)

The second incarnation of the Doctor once used a portable Stattenheim remote control to summon his TARDIS to him (DW: The Two Doctors). The TARDIS was also vulnerable to diversion or relocation by the Guardians, Eternals, and other immensely powerful beings such as the Keeper of Traken. (DW: The Ribos Operation, DW: Enlightenment, DW: The Keeper of Traken)

For a brief time the Doctor's fourth incarnation installed a Randomiser in the navigational subsystems, though this was eventually removed. (DW: The Armageddon Factor, DW: The Leisure Hive)

Sleeping quarters and related facilities
Many of the companions of the Doctor had their own rooms, (DW: Meglos), though some lived in previously used rooms. (DW: Terminus) Some companions were seen to share accommodation. (DW: The Edge of Destruction) There were at least 14 bathrooms. One had a leaky faucet for three centuries. Because he had misplaced his washers, the Doctor kept it from flooding the TARDIS by sealing it in a temporal bubble that made the same drops of water leak out over and over again. (MA: The Well-Mannered War)

Library
There was also a library inside the TARDIS. (EDA: War of the Daleks, NA: All-Consuming Fire, NA: The Dimension Riders) Known books included Jane's Spaceships (EDA: War of the Daleks) and Every Gallifreyan Child's Pop-Up Book of Nasty Creatures From Other Dimensions (NA: All-Consuming Fire) and The Time Machine by H. G. Wells (DW: Doctor Who) The Murder of Roger Ackroyd by Agatha Christie (first printing, signed, with last page missing), War and Peace, The Wonderful Wizard of Oz and The I-Spy Book of British Birds (BFA: Storm Warning). It probably also contained Black Orchid by George Cranleigh (DW: Back Orchid). At one point, the console room also incorporated a library (DW: Doctor Who). Following the TARDIS' repairs, the Eleventh Doctor claimed that he couldn't find the library, and that it would show up again at some point. (DW: The Eleventh Hour)

Wardrobe
The wardrobe was where the Doctor kept some of the clothes from his previous regenerations, as well as clothing for other people. (DW: Pyramids of Mars, DW: The Twin Dilemma, DW: Time and the Rani, DW: The Unquiet Dead, DW: The Christmas Invasion, DW: The Idiot's Lantern (not seen) ). It has clothing from all times and environments in it, to suit whichever time the TARDIS's occupant(s) find themselves in (for example Donna Noble managed to find a flapper outfit when she and the Doctor landed in the 1920s (DW: The Unicorn and the Wasp) and also a heavy fur coat when they landed in the mountains of the Ood Sphere. (DW: Planet of the Ood) ).

Cloister Room
The Cloister Room was related to the cloister bell, which sounded when disaster was imminent. (DW: Logopolis, DW: The Sound of Drums, DW: Time Crash, DW: The Eleventh Hour) When the TARDIS interior went through a metamorphosis, the Cloister Room became a grand and gothic room with an interface with the Eye of Harmony. (DW: Doctor Who)

Zero Room
The Zero Room was a room which was unaffected by the outside world. It was used as a refuge for Time Lords undergoing difficult regenerations. This room was later jettisoned so that the TARDIS could escape from Event One. (DW: Castrovalva)

Others

 * There was a laboratory which Ace used to create her Nitro-9. (NA: Cat's Cradle: Time's Crucible)
 * The TARDIS had a swimming pool area which was used by Leela. (DW: The Invasion of Time) Following the TARDIS's crash landing after the Doctor's tenth regeneration, the Swimming Pool fell in to the library, due to the TARDIS landing on its side. There may also be a new Swimming Pool in the regenerated TARDIS, although the Doctor has admitted to losing track, but is confident that it will "turn up" eventually. (DW: The Eleventh Hour) He appeared to have located it soon after, having offered to take a quick swim in order to give Amy and Rory some time alone. (DW: Amy's Choice)
 * The TARDIS at one point also had extensive utility areas and corridors, which along with the swimming pool area, became battlegrounds during an attempted Sontaran invasion of the TARDIS. (DW: The Invasion of Time) The Doctor was under the impression it had been jettisoned until he stumbled across it during his tenth incarnation. (IDW: Tesseract)
 * A food machine area was originally located near (but not in) the console room. (DW: The Edge of Destruction and others)
 * There was a zoo of endangered animals, a coffee machine and a jungle like room. (DWM: Changes)
 * There was what appeared to be a cricket club and pitch deep within the bowels of the TARDIS. (DW: Castrovalva)
 * There was a large salon which the Doctor referred to as a "boot cupboard". When Sarah Jane Smith said that it was very big for a boot cupboard he replied, "I've seen bigger boot cupboards." (DW: The Masque of Mandragora)
 * The Doctor also possesses an art gallery containing various works of art from throughout history, having rescued the artworks from the disasters which history states destroyed them (BFA: Dust Breeding)
 * According to an alternate version of the Ninth Doctor there was a zeppelin hangar somewhere in the TARDIS. (WC: Scream of the Shalka)
 * There appears to be either a kitchen, or at least a refrigerator, in the TARDIS during the Doctor's tenth incarnation. It's unclear if this is the same as the food machine area mentioned above (IDW: The Whispering Gallery).
 * There may also be a garage or some similar location suitable for storing vehicles, as the Doctor is known to have at one point kept a Vespa (motor scooter) in storage within the TARDIS (DW: The Idiot's Lantern).
 * By the time of the Doctor's tenth incarnation, several rooms from years (and centuries) past still existed deep within the TARDIS, including the cathedral-like room where the Doctor once fought the Master (DW: Doctor Who), and a bedroom that was once used by Adric. (IDW: Tesseract)

Temporal grace
The interior of the TARDIS was said to exist in a state of "temporal grace", which was supposed to ensure that no weapons can be used inside its environs. This last function is inconsistent in its application. During his travels with Lucie Miller, the Eighth Doctor mentioned that the temporal grace system had not worked in years. (DW: Earthshock, DW: Arc of Infinity, DW: The Parting of the Ways, BFA :Human Resources)


 * There are several possible explanations for this seeming inconsistency. Like the HADS (see below), the "temporal grace" could need to be manually activated (although this would raise the question of why it would be deactivated). The other possibility is that the Doctor is lying, and claims "temporal grace" to prevent intruders from attempting violence. A third option is that the temporal grace has since broken and is one of the many things the Doctor has to work on. Also note that, if real, the "temporal grace" field does not prevent weapons from being fired into the TARDIS (DW: Human Nature).

Emergency Systems
The Doctor's TARDIS contained various emergency systems, such as the Jade Pagoda, a 'life boat' of some description, which could in theory be piloted (NA: Iceberg), but in emergencies it will lock onto the nearest (spatially and temporally) planet with a breathable atmosphere and bearable climate. (NA: Sanctuary) The TARDIS also had a system which, when the TARDIS is left adrift in space unmanned, would automatically lock onto the nearest central gravity. (DW: Voyage of the Damned) There were also various emergency settings set up by the Doctor. One was set up by the Doctor as a way of rescuing his companions (but not the Doctor himself) if the Doctor's death seemed inevitable, transporting the TARDIS (with the companion inside) back to the companion's respective time and home. This would cause the TARDIS to 'die' within a period of time without the Doctor and was thus only used in emergencies (DW: Bad Wolf). Another could reunite the TARDIS with the Doctor if they were seperated; however it required another individual to enter the TARDIS and insert an 'authorised command disk' to activate it in the first instance (DW: Blink), after which it seemed to have been installed and fully integrated into the ship's systems; the TARDIS automatically commenced the emergency programme without external aid in various attempts to reach The Doctor, who had been trapped in a time-loop (SJA: The Wedding of Sarah Jane Smith).

The TARDIS was also capable of repairing itself after suffering a hull breach. (DW: Voyage of the Damned) The TARDIS has an alarm system known as the cloister bell that activates in dire circumstances. (DW: Logopolis, DW: Doctor Who (1996), DW: Children in Need Special, DW: Time Crash, DW: Turn Left, DW: The Waters of Mars, DW: The End of Time (TV story), DW: The Eleventh Hour.)

Defensive Systems
Some of the TARDIS's other functions include the Hostile Action Displacement System (HADS), which could teleport the ship a short distance away if it is attacked. (DW: The Krotons)

The TARDIS later gained some offensive systems of a sort; although this could have been caused by its development into the Edifice. This weapon allowed the Edifice/the Doctor's TARDIS to destroy Gallifrey, although this was only accomplished by channelling all of the Edifice's energy into the weapons. (EDA: The Ancestor Cell)

It was temporarily given a defensive shield utilizing a Tribophysical waveform macro-kinetic extrapolator. (DW: The Parting of the Ways)

Translation circuit
The TARDIS possessed the ability to allow both the Doctor and others to understand a wide variety of languages.
 * ''See separate article for a more in-depth discussion.

The Matrix
The TARDIS had a link to the Matrix. Following the Last Great Time War, this Matrix was the only one left. (IDW: The Forgotten)

Intuition Circuits
Using a holographic representation of the universe connected to the TARDIS' neural net, the TARDIS was effectively able to make hunches, guesses where it needed to be. Though the TARDIS was able to guess where it was needed, it was unable to inform the Doctor on what he needed to do once he got there. (VD: ...And Eternity in an Hour)

Other Abilities and Systems

 * The TARDIS appeared to be able to lock-on to the presence of another Time Lord, particularly the Doctor's family. (DW: The Doctor's Daughter) Alternatively it would block access (to seemingly create a situation) whereby another linked Doctor would be created. (DW: Journey's End)
 * The Doctor made additional modifications and additions from time to time. For example, at one point the TARDIS was equipped to write computer files to standard earth CD-ROMs (DW: World War Three), and he also at one point modified the control console to accept DVDs in order to allow Sally Sparrow to use a specialized control disc to activate the TARDIS (DW: Blink).
 * The TARDIS can be put one second out of synch with time. The Doctor did this once in order to prevent the Master from taking it. (DW: The End of Time)
 * The TARDIS also has stabilizers activated by blue buttons. These were first used by River Song, though it is unknown if the Doctor knew about these or not, though he said that they made the journey no fun.
 * The TARDIS also apparently has brakes, which, according to River Song, are always on, which is why the TARDIS lands with a characteristic wooshing noise. When she landed the TARDIS without the brakes on, it landed without any sound. Its possible she was joking about him leaving the brakes on as all other tardis take of with the same sound.

Personality
As TARDISes were intelligent, the Doctor's TARDIS had also developed a personality. It had been called "sentimental" (DW: Doctor Who (1996)) and "stupid" (by K-9) (DW: The Invasion of Time). Though intelligent, it was generally unable to communicate in words with the Doctor, relying on other methods of communication. (DW: The Edge of Destruction)

The TARDIS has also displayed a prejudicial fear of the time-locked Jack Harkness, probably relating in some way to its time travelling abilities, as the Doctor admits that due to his time related senses he finds it harder to look at Jack now. (DW: Utopia)

When the Doctor was attacked by Es'Cartress‎, the TARDIS tried to help him in the Matrix, taking the forms of his companions and helping him regain him memories. (IDW: The Forgotten)

Although the Doctor was reluctant to believe it possible, his TARDIS seems to have such a strong affinity for the Doctor that it would open and shut its doors when he snapped his fingers. The Tenth Doctor tested this ability after being informed of it by River Song, and was able to do so. Later, the Eleventh Doctor uses this ability when he takes Amy on as a companion to show off. (DW: Forest of the Dead, The Eleventh Hour)

While the Doctor was away on an adventure the TARDIS hummed to itself. (NSA: The Doctor Trap)

The Doctor has shown great tenderness towards the TARDIS, referring to it as his "dear old friend" on one occasion (DW: The Deadly Assassin), and simply "dear" on another. (DW: The Eleventh Hour) He has most commonly referred to the TARDIS as "she or "her". Although this would seem to be a term of endearment (much like how Earth males refer to their cars as "she's"), certain spin-off media suggests that the TARDIS may actually be female. (ST: The Lying Old Witch in the Wardrobe)

Problems
As the TARDIS was one of the oldest in full service and given how much the Doctor used his TARDIS, many problems had cropped up during its years of service.


 * The spring on the Fast Return Switch jammed.(DW:The Edge of Destruction)


 * The TARDIS gravitational tractor beam functioned only sporadically since it was used to pull a neutron star away from Chloris. (DW: The Creature from the Pit) Compassion was unable to use it to rescue the Doctor when he was trapped outside the TARDIS (EDA: The Taking of Planet 5), but it was functioning once more to enable the Doctor to rescue the rocket from Krop Tor (DW: The Satan Pit) and once more to pilot Earth back to it's position in space. (DW:Journey's End)


 * The chameleon circuit did not work; despite the Doctor's few attempts to fix it, he preferred it to look like a police box. (DW: Boom Town) The Doctor felt so adamantly about it, that he purposefully smashed the functioning chameleon circuit with a mallet, so it would never work again. (NA: No Future). During her brief time as the DoctorDonna, Donna Noble came up with a solution for the chameleon circuit problem, but was unable to impart this information to the Doctor before her mind began collapsing. (DW: Journey's End)


 * At the time of NA: No Future, he was using a TARDIS which had once belonged to a dead version of his third incarnation, which the main universe's Doctor later found. (NA: Blood Heat)


 * The TARDIS pool leaked and was jettisoned, (DW: Paradise Towers) but the TARDIS gained two new ones following its regeneration after the Doctor's second exile on Earth. (EDA: Escape Velocity)


 * To be piloted correctly the TARDIS needed six pilots, one on each side of the hexagonal console.(DW: Journey's End) As the Doctor was generally the only one to fly it, he had frequent problems with piloting, making a shaky ride. This may also explain why he occasionally has trouble landing in exact dates. Seen in DW: Aliens of London when he intended to return Rose Tyler twelve hours after her departure from earth (DW: Rose) but instead landed twelve months later.
 * The Temporal Satnav was said to be "on the blink". (DW: Dreamland)
 * The sound made by the TARDIS when it dematerialises and rematerialises is actually not supposed to happen, but is the sound of the Doctor incorrectly using the brakes. (DW: The Time of Angels)

Behind the scenes

 * An online comic WC: Just Another Thursday by Paul Cornell, published on the BBC website in 2008, suggests that the TARDIS has the ability to change its size to an almost infinite degree, at one point becoming even large enough to envelop (and protect) the entire Earth. Given that this rather extreme ability has not been mentioned elsewhere, and given the nature of the BBC Writers' Comics series as being fun one-offs as opposed to serious contributions to the canon, it can't at present be said whether the TARDIS canonically has the ability Cornell describes.
 * The ubiquity of the TARDIS to the Doctor Who franchise was recognized in late 2009 when the BBC unveiled a new version of the Doctor Who logo which began to be used in 2010; the logo incorporates the initials DW formed in the familiar police box shape of the Doctor's TARDIS.
 * Although the TARDIS has been a constant presence in the series since 1963, it has almost always been essentially a mode of conveyance, with the majority of stories taking place away from the vessel. There have been a few exceptions, such as DW: The Edge of Destruction and Time Crash in which the entire action of a story takes place within the TARDIS. DW: The Invasion of Time was the first story to give viewers an extensive tour of the bowels of the TARDIS (other than occasional prior glimpses of individual rooms); a more modest "tour" occurred in DW: Castrovalva. Viewers also saw new aspects of the TARDIS in the 1996 TV movie. In the comic strips, several stories have taken place almost entirely within the TARDIS, including DWM: Changes and IDW: Tesseract.
 * In a recent interview with the creators of Series 5, some details about the new "redecoration" of the Doctor's TARDIS were revealed: "It must be three times the size of Tennant’s, on multiple levels with staircases in between. Less grubby than its predecessor, with a transparent plastic floor on the main level, its walls are resplendent with polished copper and its central column features a blown glass decoration that could be straight from Tales of the Unexpected. There are old car seats and downstairs – downstairs! – a swing. With a nod to Paul McGann’s Tardis, the central column features an old TV screen on an extendable trellis. It also has a 1980s-style computer keyboard, and a His-Master’s-Voice style trumpet speaker.