Audi A4 2001, Руководство пользователя, Страница: 57 / 88

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Control unit for trailer recognition J345
A separate control unit is required for trailer
operation. This transmits the vehicle lighting
system convenience CAN messages from the
vehicle electrical system control unit to the
trailer lights. A parallel link from the trailer
socket to the vehicle wiring would result in
fault detection via the microprocessor in the
vehicle electrical system control unit.
The diagnostic function of the control unit for
trailer recognition is performed via the
vehicle electrical system control unit J519,
address word 09.
In the case of faulty communication
between the control unit for trailer recog-
nition and the vehicle electrical system
control unit, the rear lights are actuated
as a warning signal.
R
T
Address word 09 - vehicle electrical system/
Central convenience
electronics
Communication takes place by means of the
convenience data bus via the central conven-
ience electronics, as no separate K-wire
leads to the vehicle electrical system control
unit. For this reason, intact central conven-
ience electronics are essential for perform-
ing self-diagnosis.
K wire
CAN
BUS
Central convenience
electronics J393
SSP254_018
J389
J388
J387
J386
Door control units
Control unit for vehicle
electrical system J519
Control unit for trailer
recognition J345
09 – Electronic central electrics
8E0907279B
int. load module RDW 0811
Code 101
Dealership No. 6803
02 - Interrogate fault memory
03 - Final control diagnosis
04 - Basic setting
05 - Erase fault memory
06 - End output
07 - Encoding control unit
08 - Read measured value block
09 - Read individual measured value
10 - Adaption
11 - Log-in procedure
Measuring
equipment
Skip Print Help
Steering column
switch module J527
Vehicle self-diagnosis
Steering wheel
electronics
module J453
SSP254_016
VAS 5051