light AUDI A6 ALLROAD 1999 C5 / 2.G Pneumatic Suspension System

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BL NSL 31 58l RF BR 30 34 58r 3110 11 12
The trailer operation signal …
..... comes from the F216 contact switch in the
trailer socket.
When the plug is connected, contact switch
F216 connects control unit J197 to earth.
See also “Trailer operation”.
Headlamp range control signal
As changing vehicle levels is axle-based (i.e.
for both sides of an axle at once), this would
produce a short-term visibility range
reduction when driving at night.
For this reason, the allroad quattro is fitted
with an automatic dynamic headlamp control
system (also without gas-discharge
headlamps). The automatic dynamic
headlamp range control system maintains the
light beam at a constant angle while the
vehicle level changes.
In order to prevent irregularities in the road
surface, such as bumps or potholes, from
causing the headlamp range to alter
unnecessarily, long reaction times are set
when the vehicle is travelling at relatively
constant speeds (little or no acceleration). If level change takes place (e.g. motorway
mode), the 4-level air suspension control unit
J197 transmits a voltage signal to the
headlamp range control unit J431.
This activates the HRC immediately and
controls the bodywork movements.
Level change process:
Raising - rear axle first, then front axle
Lowering - front axle first, then rear axle
243_014
Trailer socket to the self-levelling suspension
control unit J197 (pin 2/10)
from the rear fog light
switch
F216

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Key to function diagram
E281 Self-levelling suspension operating
unit
F216 Contact switch for switchable rear fog
light
G76 Self levelling suspension sender, RL
G77 Self levelling suspension sender, RR
G78 Self levelling sender, FL
G289 Self levelling suspension sender, FR
G290 Compressor temperature, self-
levelling suspension sender
G291 Self-levelling suspension pressure
sender
J197 Self-levelling suspension control unit
J403 Relay for self-levelling suspension
compressor
J429 Control unit for central locking
J431 Control unit for headlamp range
control
N111 Discharge valve for self-levelling
suspension
N148 Valve for FL suspension strut
N149 Valve for FR suspension strut
N150 Valve for RL suspension strut
N151 Valve for RR suspension strut
N311 Valve for self-levelling suspension
pressure accumulator
K134 Self-levelling suspension warning
lamp
V48 Left headlamp range control motor
V49 Right headlamp range control motor
V66 Self-levelling suspension compressor
motor= Input signal
= Output signal
= Positive
= Earth
= Bi-directional
= CAN bus/signal wire
Auxiliary signals:
CAN low
CAN high
Door contact signal
Diagnostic connector for K wire
Vehicle locked signal
Trailer operation signal (F126)
Terminal 50 signal
Driving speed signal
Terminal 56
Diagnostic connector for K wire
to the instrument cluster
Driving speed signal from ABS control unit,
speed sensor output, rear left
1
2
3
4
5
6
7
8
I
II
III
IV
Terminal 58s
Terminal 58d
ESP button
ESP button
A
B
C
DHeadlamp range control signal
9
Power supply J431
10

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In trailer operation, normal mode must
always be selected and care must be
taken that the system is switched to
manual mode (e.g. no automatic
switching to manual mode if trailer
operation signal fails).
In difficult driving conditions, high
level 1 or high level 2 can be selected,
however, normal level must be selected
before a driving speed of 35 km/h is
exceeded.
Driving at low level or in automatic
mode is not permitted.
Trailer operation
The correct position of the tow bar on the
trailer attachment during trailer operation is
indicated in normal mode.
Contact switch F216 in the 13 pin trailer
socket is used to signal that the trailer plug is
inserted, i.e. indicates trailer operation (see
description “Trailer operation signal”.
If trailer operation is recognised, the manual
mode is automatically activated (LED “man”
lights up) whereby the automatic raising
process is stopped.
Normal level is set by the driver via control
unit E281.
243_015
Normal level