Volkswagen The Golf 2004 Service Training page 22

Onboard power supply
The data bus diagnostic interface J533
Due to the vast range of functions in the vehicle,
large amounts of data must be transferred.
To guarantee optimal exchange of data, several
data bus systems are required.
The function previously integrated in the dash
panel insert or onboard supply control unit is
now assumed by the separate data bus
diagnostic interface (Gateway). It forms the
interface for data bus systems that are
independent of each other and allows
information to be exchanged without conflict or
interference.
Fitting location
The data bus diagnostic interface is installed
beneath the dash panel, above the accelerator
pedal.
Master functions
The data bus diagnostic interface takes on the
master functions of terminal 15 run-on and sleep
and wake-up modes.
Further information can be found in
SSP 307
"The Touran - Electrical system".
22
S319_014