display AUDI A6 ALLROAD 1999 C5 / 2.G Pneumatic Suspension System
[x] Cancel search | Manufacturer: AUDI, Model Year: 1999, Model line: A6 ALLROAD, Model: AUDI A6 ALLROAD 1999 C5 / 2.GPages: 44, PDF Size: 2.47 MB
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Contents
System description . . . . . . . . . . . . . . . . . . . . 4
The self-study programme is not intended as a workshop manual.
The self-study programme will provide you with information on
the design and functions of the different assemblies/systems.
New
NoteImportant:
Note
Page
For maintenance and repairs please refer to the current technical
literature.
Operation and display
Operation ................................................................................. 7
Display ..................................................................................... 8
Self-levelling suspension control unit J197 ....................... 34
Modes .................................................................................... 35
Control concepts
Service
Special tools .......................................................................... 38
Basic system settings .......................................................... 39
Self-diagnosis ....................................................................... 40
General overview .................................................................. 41
Control strategies
System components
Air springs .............................................................................. 14
Air suspension ...................................................................... 17
Diagram of pneumatic system ............................................. 20
Solenoid valves ...................................................................... 21
Temperature sensor G290..................................................... 22
Pressure sensor G291............................................................ 22
Level senders G76, G77, G78, G289 ..................................... 23
Warning lamp K134 ............................................................... 27
Operating unit E281 .............................................................. 28
CAN information exchange ................................................. 29
Additional interfaces ............................................................. 30
Function diagram ................................................................... 32
Interfaces
Control strategies, control unit 4Z7 907 553A ................... 10
Control strategies, control unit 4Z7 907 553B ................... 12
ESP safety switching ............................................................ 13
Order No.:
507.5320.01.00
This figure can be ordered as a size A0 poster through
Bertelsmann Distribution for a net price of DM
15.00 DM/7.50 EUR
.
Direct ordering through Bertelsmann only applies to Germany.
Dealers in export markets are requested to contact their importer.
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Operation and display
Operation
The self-levelling control unit E281 is used to
control the 4-level air suspension and the
display/monitor the system status.
Certain level changes occur automatically
during normal driving (see Control strategy).
Within defined conditions (see Control
strategy) the driver can use the “raise” or
“lower” buttons to select an appropriate level
at any time. Pressing the “raise” button once selects the
next highest level. By pressing the button
repeatedly, it is possible to change, e.g.
directly from low level to high level 1. High
level 2 cannot be selected until high level 1
has already been set.
Changing to a lower level is performed in the
same manner as described above using the
“lower” button. By pressing several times (x3)
it is possible to shift directly from high level 2
to the low level.
Operating unit for self-levelling E281
241_062
It is possible to switch to a higher level
only when the engine is running or
when sufficient pressure is present in
the pressure accumulator.
It is possible to change to a lower level even
when the engine is switched off.
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Operation and display
If the actual level deviates greatly from the
reference level, this is indicated to the driver
with flashing LEDs (according to a level
change).
Significant deviations are:
– at least one axle level is below the next
level down.
– both axle levels are above the next level up.
Display
The four LEDs which are arranged one on top
of the other in the display zone illuminate
continuously to indicate the current level
status.
Only the control procedure which has been
triggered by a level change (whether
automatically or manually) is indicated by one
or several flashing LEDs. Once the target level
has been reached, the flashing changes to
continuous illumination.
The LEDs in the “raise” and “lower” buttons
indicate actuation and the control direction. If
the LED flashes, a level request has been
denied (e.g. if the driving speed is too high)
243_020
Lower button Raise button ESP button
Manual mode display
Display zone with 4 level-indicating LEDs Actuation/control direction display Actuation/control direction display
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243_022
243_023
243_024
243_025
Other button functions
Automatic switching
The so-called “manual mode” can be
switched on or off by pressing the “raise” or
“lower” button for at least 3 sec. The yellow
LED marked “man” indicates to the driver that
the vehicle is in manual mode.
The automatic “parking level control” and
“motorway mode” functions are deactivated
in manual mode.
Switching off control system
The control system is switched on or off by
pressing both level buttons for longer than
5 seconds.
When the control system is switched off, the
LEDs in the operating unit for manual mode,
both level buttons and the warning lamp K134
are illuminated.
The level-indicating LEDs show the level set.
The corresponding LED is continuously
illuminated.
A control system that has been switched off
will be automatically switched back on again
when the driving speed exceeds approx.
10 km/h (unless the lifting platform mode is
recognised).
The control system can also be switched off
using the diagnostic testers (see Workshop
Manual).
It is often advisable to switch off the
system during repair work (e.g. during
axle measurement or if the pressure
lines have been detached) in order to
prevent the compressor from running
unnecessarily.
Display example: Manual mode and NL
Display example: Raising from LL to HL1
Display example: Raising from HL1 to HL2
Display example: Lowering from NL to LL
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F
F
F
F
F
S
F
S
S F
3
1
7
52/25
2/50
2/49
2/05
2/04
2/01
2/02 9
10
4
8
System components
Control unit J197 transmits the information
concerning the vehicle level and the system
status back to the E281 via the K wire,
whereupon the electronic unit actuates the
relevant LEDs.
For self-diagnosis reasons, the “raise” button
is designed as a redundant additional
interface.
Operating unit for self-
levelling E281
The operation and displays of the operating
unit are described on page 7. In this section,
the function of the operating unit will be
described.
The interface to control unit J197 is
performed by means of a data
communication wire (K wire)
An electronic unit integrated into the
operating unit evaluates the signals from the
level button and transmits these as a
corresponding data protocol via the K wire
to control unit J197.
243_013
The K wire between E281 and J197
bears no relation to the self-diagnostic
K wire between J197 and the
diagnostic testers.
Electronic unit
Control unit J197 Terminal 30 Terminal 15
Raise button
K wire
Operating unit E281
Terminal 58s
Terminal
58d
to the ESP control unit
from the ESP control unit
HL2
HL1
NL
LL
man
High
Low
Lower button
ESP buttonF = LEDs for functional illumination
S = LEDs for switch illumination
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Self-diagnosis
Address word: 34 Self levelling suspension
Both generations of diagnostic tester
(V.A.G. 1551/1552 and VAS 5051) are suitable
for communication with the 4-level air
suspension control unit.
Due to the limited capacity of the tester
program cards, there are display text
limitations in the case of diagnostic testers
V.A.G. 1551 and 1552 (see. e.g. Workshop
Manual, Self-diagnosis function 03, Final
control diagnosis).
Service
198_039