Audi TT (2007 year). Manual — part 238

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.

33

Final control diagnostics

The shock absorber dampers can be activated selec-
tively in the final control diagnostics.
The shock absorber dampers are activated by apply-
ing a current of 2A.

Data blocks

The data blocks are used to check key system status
information.The temperature values calculated for
the dampers and control unit, for example, are rep-
resented in data block 28.

Cold starting

When control unit J250 or shock absorber dampers
are replaced, the control unit must determine the
electrical resistance values of the damper coils at
ambient temperature. The control unit saves these
values as "standard values" for purposes of temper-
ature compensation (refer to "Special functions -
temperature model").
This function is activated automatically after igni-
tion on, provided the vehicle has been out of use for
at least 3 hours (e.g. even after a a cold start in the
morning) . During this time not in use, the tempera-
tures of the dampers have adjusted to the ambient
temperature. If the mechanic has fitted shock
absorber dampers which are already at ambient
temperature (e.g. parts sourced directly from the
spare parts warehouse), the resistance measure-
ment function can be started immediately by acti-
vating the "Cold start" function with the diagnostic
tester.

Flashing

The control unit software can be flashed by an exter-
nal data carrier (CD, online interface) .

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.

34

Wheels and tyres

Overview

381_047

7.5J x 16 ET 45 (1)
Cast aluminium
wheel painted
225/55 R 16

Engine

Basic wheels

Optional wheels

Winter wheels

4-cylinder

6-cylinder

8J x 17 ET 47 (3)
Cast aluminium
wheel painted
225/50 R 17

9J x 18 ET 52 (5)
Cast aluminium
wheel polished,
bicolor
225/50 R 17

7J x 16 ET 47 (7)
Cast aluminium
wheel painted
225/50 R 17

9J x 18 ET 52 (9)
Cast aluminium
wheel painted
245/40 R 18

8.5J x 17 ET 50 (2)
Forged aluminium
wheel painted
245/45 R 17

9J x 18 ET 52 (4)
Cast aluminium
wheel painted
245/40 R 18

9J x 18 ET 52 (6)
Cast aluminium
wheel painted
245/50 R 18

7J x 17 ET 47 (8)
Forged aluminium
wheel painted
225/50 R 17

also available optionally as SST wheel

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.

35

Self Supporting Tires (SST)

SST tyres have run-flat capability because of their
modified design compared to conventional tyres.
Much stiffer tyre sidewalls enable the vehicle to
drive on for up to 50 km at a maximum speed of
80 kph even after a total loss of pressure.

Due to their modified tyre geometry, special wheels
with the designation EH2 (extended hump 2) are
used for SST tyres.To prevent inward displacement
of the tyre beads in case of loss of tyre pressure, the
bead seating has been modified substantially in
comparison with conventional wheels. The bead is
seated in a recess which supports the tyre towards
the inside of the rim.

381_048

381_049

Conventional wheel geometry

extended hump 2

Note

Tyres run in "limp home" mode must always be
replaced!
Special tools must be used to fit and remove
SST tyres.For detailed information, refer to the
"Workshop Equipment" catalogue

The special 17" wheels on the Audi TT can be used
both for conventional tyres and for SST tyres. In the
case of the 18" wheels, conventional tyres are avail-
able in combination with conventional rims. SST
tyres are always combined with the low tyre pres-
sure indicator.

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.

36

Wheels and tyres

Low tyre pressure indicator

Overview

In all markets except North America the Audi TT fea-
tures a newly developed low tyre pressure indicator.

Being an indirect measuring system, no tyre pres-
sure sensors are installed in the wheels.

381_050

J533

J793

J104

J285

G44

G45

G47

G46

Dash panel insert CAN bus

Powertrain CAN bus

E492

J285

Control unit with display in dash panel insert

J533

Data bus diagnostic interface

J793

Tyre pressure monitor control unit 2

E492

Tyre pressure monitor display button

J104

ESP control unit

G44-47 Wheel speed sensor