Audi TT (2007 year). Manual - part 271

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.

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Control unit with display in dash panel insert 

J285

Convertible top operation warning lamp

K215

Centre display 

Dash panel insert

Convertible top operation control unit J256

Convertible top operation 
hydraulic pump V118

Convertible top lock motor V223

Convertible top cover motor V381/V383

Diagnostic port

Convenience system 
central control unit J393

Door control units J386/J387

Heated rear window Z1

Onboard power supply control unit J519

Convertible top convenience opening/closing

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.

30

Electrical convertible top control system

Headlight range control, 

control unit 

J431

ECD control unit 

(electronically controlled 

damping) 

J250

Power output module 

for right headlight

J668

Power output module 

for left headlight

J667

ABS 

control unit

J104

Selector lever 

E313

Twin clutch

gearbox 

mechatronics

J743

Engine

Control unit

J623

Airbag 

control unit

J234

Four-wheel drive

control unit

J402

Tyre pressure

monitor 

control unit 2 

J793*

Power steering 

control unit

J500

Steering angle 

sender

G85

Steering column 

electronics 

control unit 

J527

Multifunction 

steering wheel

control unit 

J453

Powertrain CAN bus

Infotainment CAN bus

Convenience CAN bus

Dash panel insert CAN bus

Diagnostics CAN bus

LIN bus

Subbus system

Panasonic bus

Topology and networking

On the next two pages you will find an overview of the networking of the individual control units in the 
Audi TT Roadster. The convertible top operation control unit J256 is integrated in the convenience CAN bus.

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.

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Rain and light 

detector sensor 

G397

Wiper motor 

control unit 

J400

Alarm horn 

H12

Anti-theft alarm 

system sensor 

G578

Tyre pressure

monitor 

control unit

J502**

Onboard 

power supply

control unit

J519

Convenience 

system central 

control unit 

J393

Climatronic 
control unit

J255

Auxiliary air heater 

control unit 

J604

Convertible top 

operation 

control unit

J256

Parking aid 

control unit 

J446

Front passenger 

door control unit

J387

Door control unit,

driver side 

J386

TV tuner

R78

Digital sound 

package 

control unit 

J525

Radio

R

Control unit with 

display for radio 

and navigation

J503

CD changer

R41

Digital satellite 

radio tuner 

R190

Telephone 

transmitter and 

receiver unit 

R36

Data bus diagnostic interface 

J533

Control unit with display in 

dash panel insert 

J285

Diagnosis connection

* 

for tyre pressure monitoring system 2 only (ECE = Europe)

** 

for tyre pressure monitor only (SAE = North America)

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.

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391_076

391_054

Reference

For information on the CAN data bus, 
refer to Self-Study Programme 238 
"Data exchange across CAN data bus I" 
and 269 "Data exchange across CAN data 
bus II".

Electrical convertible top control system

Convertible top operation control unit J256

Data bus diagnostic interface J533

Data exchange

To ensure smooth operation of the convertible top, 
the convertible top operation control unit J256 
requires various information.
In addition to the information received from the 
system's sensors, the control unit requires 
information from other automotive systems, 
e.g. ESP.
Other control units are also dependent on the 
information supplied by the convertible top 
operation control unit. This information is 
exchanged across the CAN data bus.

The convertible top operation control unit is 
integrated in the convenience CAN bus and sends 
and receives data across this CAN bus.

Data exchange between the individual CAN data 
bus systems is effected via the data bus diagnostic 
interface J533.

There is an intensive and continuous exchange of 
data between the individual automotive systems.

The data bus diagnostic interface is located below 
the dash panel adjacent the pedal bracket. The 
control unit is accessible from the driver footwell.