Audi TT (2007 year). Manual — part 274

Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.

41

391_024

391_069

391_070

391_040

Rear axle for quattro four-wheel drive

Rear axle for front-wheel drive

Attachment of the diagonal struts for quattro four-wheel drive

Attachment of the diagonal struts for front-wheel drive

To increase vehicle rigidity, additional diagonal struts are fitted in the rear section of the Audi TT Roadster.
The struts connect the rear axle carriers to the body through additional mounting points. The threaded
couplings on the axle carriers are different for front-wheel drive or quattro drive.

Rear suspension

Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.

42

391_016

Heating and air conditioning system

The name has been adapted and the heating system
is now:
Heating control unit, Climatronic control unit J255.
Of course, both air conditioner control units have
different part numbers.

Seat heating is likewise an optional extra in the
Audi TT Roadster.
Three heater settings can be selected at the touch
of a button. The selected heat output setting is
indicated by LEDs above the button.

Vehicles equipped with a heating system only are not fitted with various components which are required for
temperature control in vehicles equipped with an air conditioning system.
Vehicles equipped with a with heating system only do not, for example, have the temperature flap control
motor, right V159, the front left chest vent temperature sender G385, the vent temperature sender, left and
right footwells G261, G262, the evaporator out-flow temperature sender G263, the dash panel temperature
sensor G56 and its temperature sensor blower V42, the sunlight penetration photo sensor G107, the high
pressure sender and, finally, the air conditioner compressor.

The heating system and the air distribution housing differ from one another in that certain components are
not present heating systems, as compared to air conditioning systems.
Refer to the Workshop Manual for further information.

Function key "Air recirculation"

Rotary control "Temperature"

Rotary control "Air flow"

Rotary control "Air distribution"

Heating control unit, Climatronic control unit J255

Seat heating button with LEDs

Heating system

The entry-level engines of the Audi TT Roadster are
equipped as standard with a heating and ventilation
system.
Heater control unit, Climatronic control unit J255,
differs from the control unit with air conditioning
system in regard to its design.
The rotary temperature control has neither degrees
nor units of temperature.
The designations of the Climatronic control unit
J255 of the heating system and the air conditioning
system in the Audi TT Coupé ‘07 and Audi TT
Roadster are identical.

Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.

43

391_017

Ambient temperature sensor G17

In the heating system, ambient temperature sensor
G17 serves only to calculate the "on" time of the
heated rear window Z1.

In Audi TT Roadster vehicles which are equipped
with a heating system only, the two radiator fans
(number of fans depends on engine specification)
are not controlled by the heating control unit,
Climatronic control unit J255.

Radiator fan V7 with radiator fan control unit J293

The heating control unit, Climatronic control unit
J255, can only send the fan(s) on command to the
engine control unit in the final control diagnostics
function.
When the engine is running, the engine control unit
activates the radiator fan(s) directly or via the
radiator fan control unit J293.

Water drains

The two water drains in the plenum chamber are
located on the outer left and right sides of the
plenum chamber. The condensation drain hose of
the air conditioning system is not required.
The port on the centre tunnel of the body must be
sealed with a plug in vehicles equipped with a
heating system only.

Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.

44

391_065

Interior monitor

Overhead module with anti-theft alarm sensor G578

Microphone

Infrared transmitter

Anti-theft alarm system sensor

Infrared receiver

Microphone

Interior light,
front passenger side

Overhead module connector
(interior light)

Connector of the antitheft
alarm system sensor

Interior light,
driver's side

The anti-theft alarm sensor G578 is again integrated
in the overhead module. Both the sensor G578 and
the overhead module are parts adopted from the
TT Coupé ´07.
Despite the use of identical components, the anti-
theft alarm sensor G578 must know what vehicle it
is installed in.
This information is provided by a bit using the
coding of the convenience system central control
unit J393, which differentiates between the
TT Coupé and the TT Roadster.

If the convertible top is closed and one of the
windows in the vehicle is open, the anti-theft alarm
can be activated, but will operate at a lower
sensitivity level.

With regard to the functional principle of the anti-
theft alarm, please note that the alarm system
cannot be activated unless the convertible top is
closed.

Anti-theft alarm system

The TT Roadster ´07 has adopted the anti-theft
alarm sensor G578 from the TT Coupé ´07.
This sensor incorporates both the interior
monitoring sensors and the tilt sensor.
The interior monitoring sensors of the
TT Roadster ´07 now use ultrasound.
The predecessor model of the TT Roadster
used microwaves.