2004 Alfa Romeo 156 Owner handbook (in English)

GETTING TO KNOW YOUR CAR
175
COMPENSATION FOR TILT(fig. 169)
If the car is fitted with xenon headlights,
beam aiming is electronic and therefore con-
trol (A) on the mask near the steering col-
umn is not present.
When the vehicle is loaded, the beam from
the headlights is raised due to the back-
wards tilt of the vehicle.
In this case the headlights must be ad-
justed using control (A) located on the plate
at the side of the steering column.This control has four positions corre-
sponding to various vehicle loads given be-
low:
– position 0: 1 or 2 people occupying
front seats, full fuel tank, on-board equip-
ment present;
– position 1: 5 people on-board;
– position 2: 5 people on-board, luggage
compartment full (50 kg approximately);
– position 3: driver and 300 kg in lug-
gage compartment.fig. 169
A0B0240m
Check the positioning of
the headlight beams every
time you change the load to be car-
ried.
WARNING
ADJUSTING THE FRONT
FOGLIGHTS (for versions/markets where
applicable)
To adjust the height of the beam of the
front foglights, act on adjusting screw (A-
fig. 170).fig. 170
A0B0239m
Contact Alfa Romeo Au-
thorized Services to have
the headlights correctly ad-
justed.

GETTING TO KNOW YOUR CAR
176
The electromechanical system to auto-
matically keep constant trim makes the
headlight tilt compensating device unnec-
essary.
The xenon lamps have very long life which
makes possible fault very unlikely.
If necessary, have the sys-
tem checked and repairs (if
any) made only by Alfa Romeo Au-
thorized Services.
WARNING
GAS DISCHARGE HEADLIGHTS(optional for versions/markets
where applicable)
The gas (xenon) discharge headlights op-
erate with a voltaic arc, in an ambient sat-
urated with pressure xenon, instead of the
glow filament.
The resulting illumination is sensibly higher
to that of conventional lamps, both for light
quality (clearer light) and for the width and
positioning of the illuminated area.
The advantages of better illumination can
be perceived (due to less eyesight fatigue
and greater orientation capacity for the dri-
ver, which in turn means higher driving
safety) especially in case of bad weather,
fog and/or insufficient road signs, thanks
to the better illumination of the side parts
of the visual field, normally obscured.The large increase of the side part illumi-
nation increases driving safety since it allows
the driver to better see the other users on
the edge of the road (pedestrians, cyclists
and bikers).
The triggering of the voltaic arc requires a
very high voltage, while subsequent power
supply can take place at a low voltage.
The headlights achieve their top luminos-
ity approx. 15 seconds after they are
switched on.
The intense light produced by this type of
headlights requires the use of an automatic
system to keep headlight trim constant and
avoid dazzling the vehicles coming from the
opposite direction in case of braking, accel-
eration or when carrying loads.

GETTING TO KNOW YOUR CAR
177
DIPPED BEAM HEADLIGHT
AIMING FOR LEFT-HAND/
RIGHT-HAND DRIVING(only for versions with gas
discharge headlights)
As regards cars equipped with gas dis-
charge headlights (xenon lamps)(optional
for versions/markets where applicable) with
very great lighting power, when passing
from a country with right-hand driving to one
with left-hand driving, or vice versa, it is nec-
essary to modify the orientation of the
dipped beam headlights, to optimize the il-
lumination of the road edge and avoid daz-
zling the vehicles coming from the opposite
direction.
To have this operation
carried out, contact Alfa
Romeo Authorized Ser-
vices.
When you go back to your
country of origin, remem-
ber to have the dipped beam head-
light orientation modified again.
WARNING
In the event of a failure, though being un-
able to rely on the antilock effect, there is
absolutely no adverse effect on vehicle brak-
ing performance in terms of braking capac-
ity.
If you have never used a car with ABS be-
fore, you are advised to learn how to use
it with a few preliminary trials on a slippery
surface, naturally under safety conditions
and fully adhering to the Highway Code of
the country concerned. You are also advised
to carefully read the following information.
The advantage of the ABS compared with
the conventional system is that it makes it
possible to maintain maximum vehicle han-
dling performance also in the case of hard
braking under grip limit conditions, avoiding
wheel lock.
Do not however expect the braking dis-
tance always to be reduced with the ABS
system: for example, on soft surfaces such
as gravel or fresh snow on slippery surfaces,
the distance might increase.
ABSThe car is fitted with an ABS system which
prevents wheel lock when braking, better
exploits wheel grip and keeps the vehicle
controllable within the limits of the available
grip also during emergency braking.
The driver can feel that the ABS is opera-
tional by a light pulsing of the brake pedal,
accompanied by noise.
This should not interpreted as malfunc-
tioning of the brakes, but it is the signal to
the driver that the ABS system is working:
it is the warning that the car is travelling at
the limit of grip an that, therefore, it is nec-
essary to adapt the speed to the type of road
on which you are travelling.
The ABS system is an additional part of the
basic braking system; in the event of a fault
it is disabled, leaving the braking system
in the same conditions as a car without ABS.

GETTING TO KNOW YOUR CAR
178
Braking on corners always requires the ut-
most caution, even with the help of the ABS.
The most important piece of advice, how-
ever, is the following:Following these instructions you will be
in a condition to obtain peak braking per-
formance at all times.
WARNINGCars fitted with ABS must
only be fitted with wheel rims, tyres and
brake linings of the type and brand approved
by the Manufacturer.
The braking system is completed by the
electronic control braking distribution system
called EBD(Electronic Braking Force Dis-
tributor) which distributes the braking action
through the ABSsystem control unit and
sensors.
In the event of a system
fault, with lighting up of
the
>
warning light on the instru-
ment cluster (together with the
message + symbol shown by the
display), have the vehicle checked
immediately by Alfa Romeo Au-
thorized Services, driving slowly
to be able to regain full system
performance.
WARNING
When the ABS cuts in and
you feel the pedal pulse, do
not reduce the pressure, but keep
the brake pedal firmly pressed
with no fear; this way you will
stop in the shortest possible space,
compatibly with the conditions of
the road surface.
WARNING
The car is fitted with an
electronic brake distributor
(EBD). If the
>
and
x
warning
lights, where required, come on at
the same time (together with the
message + symbol shown by the
display) when the engine is run-
ning, there is an EBD system fault;
in this case, violent braking may
lock the rear wheels too early, with
the possibility of skidding. Drive
extremely carefully to the nearest
Alfa Romeo Authorized Services to
have the system checked over.
WARNING
In order to be able to exploit as far as pos-
sible the possibility of the antilock system
in the case of need, it is wise to follow a few
pieces of advice:
The ABS exploits the avail-
able grip in full, but it can-
not increase it; therefore, caution
is required on slippery surfaces,
without running unnecessary risks.
WARNING
If the ABS cuts in, it means
that the grip limit between
the tyres and the road surface has
been reached: it is necessary to
slow down and adapt driving to
the grip available.
WARNING

GETTING TO KNOW YOUR CAR
179
If the
x
low brake fluid
warning light comes on (to-
gether with the message + symbol
shown by the display), stop the car
immediately and contact the near-
est Alfa Romeo Authorized Ser-
vices. Indeed, any leak of fluid
from the hydraulic system com-
promises the effectiveness of both
the conventional brake system and
the system with antilock system.
WARNING
The turning on of the
>
warning light (together
with the message + symbol shown
by the display) with the engine
running normally indicates an ABS
system fault. In this case the brak-
ing system preserves its effec-
tiveness, without however making
use of the antilock device. Under
these circumstances, the EBD sys-
tem may fail to give top perfor-
mance. In this case, too, you are
recommended to contact Alfa
Romeo Authorized Services imme-
diately, driving in such a way as to
avoid abrupt braking, to have the
system checked.
WARNING
VDC AND ASR
SYSTEMS(where required)VDC SYSTEM (VEHICLE
DYNAMICS CONTROL):
GENERALThe VDC is an electronic vehicle stability
control system which, acting on the torque
and braking the wheels in a differentiated
manner, helps to bring the car back to the
correct course in the event of loss of grip.
While travelling the car is subjected to lat-
eral and longitudinal forces that may be
controlled by the driver up to when the
tyres offer adequate road-holding; when
this falls below the minimum level, the car
starts to deviate from the course required
by the driver.
Above all on rough surfaces (such as cob-
bles, or due to the presence of water, ice
or soil), changes in speed (when accelerat-
ing or braking) and/or course (bends or the
need to avoid obstacles) can cause the tyres
to lose grip.When the sensors detect the conditions
that would lead to skidding, the VDC system
acts on the engine and brakes generating
a stabilising torque.
The system performance
levels, in terms of active
safety, should not induce the dri-
ver to run pointless and unjustified
risks. Driving conduct should al-
ways be suited to the conditions of
the road surface, vision and traf-
fic. The responsibility for road
safety is always and anyway the
vehicle driver’s concern.
The VDC system helps the driver
to keep control of the car in the
event of loss of tyre grip.
The forces induced by the VDC sys-
tem to control the lack of stability
of the car always and anyway de-
pend on the grip between the tyre
and the road surface.
WARNING

GETTING TO KNOW YOUR CAR
180
The heart of the VDC system is the VDC
control unit which with the data supplied by
the sensors installed on the car, calculates
the centrifugal forces generated when the
car is cornering. The yawing sensor detects
the rotations of the car around its own ver-
tical axis. The centrifugal forces generated
when the car is cornering are detected by
a highly sensitive lateral acceleration sensor.
The stabilising action of the VDC system is
based on calculations made by the
system’s electronic control unit which
processes the signals received from the
steering wheel rotation, lateral acceleration
and individual wheel rotation sensors. These
signals allow the control unit to recognise
the manoeuvre the driver intends to do
when turning the steering wheel.
The control unit processes the information
received from the sensors and is therefore
capable of detecting the position of the car
and comparing it with the trajectory the dri-
ver would like to follow instant by instant.
In the event of a discrepancy, the control
unit chooses and commands the most suit-
able action to bring the car back to the re-
quired course within a fraction of a second:
braking one or more wheels at a different
braking force and, if necessary it reduces the
power transmitted by the engine. The corrective actions are changed and con-
trolled continuously until the car returns to
the required course.
The action of the VDC system considerably
increases the active safety of the vehicle un-
der many critical situations and it is partic-
ularly useful also when the road surface grip
conditions change.
For the VDC, ASR and ABS
systems to work correctly,
the tyres must be of the same
brand and type on all wheels, in
perfect conditions and above all of
the specified type, brand and size.
WARNING
During use of the compact
spare wheel, the VDC sys-
tem continues working. It should be
borne in mind that the spare wheel
is smaller than a normal tyre,
therefore its grip is lower than that
of the other tyres of the car.
WARNING
VDC SYSTEM OPERATIONThe VDC system turns on automatically
when the car is started and cannot be
switched off. It is however possible to cut
off operation of the ASR system pressing the
corresponding button on the centre console.
The main components of the VDC system
are:
– an electronic control unit which
processes the signals received from the var-
ious sensors and brings about the most ap-
propriate strategy;
– a sensor that detects the position of the
steering wheel;
– four sensors that detect the rotation
speed of each wheel;
– a sensor that detects rotation of the car
around the vertical axis;
– a sensor that detects lateral acceleration
(centrifugal force).

GETTING TO KNOW YOUR CAR
181
ASR FUNCTION (ANTISLIP
REGULATION): GENERALThe ASR system integrates the VDC sys-
tem controlling the vehicle drive and com-
ing into operation automatically each time
one or both driving wheels skid.
Two different control systems are activated,
depending on the skidding conditions:
– If skidding concerns both driving wheels,
because it is caused by the excessive power
transmitted, the ASR system cuts in reduc-
ing the power transmitted by the engine.
– If skidding concerns only one driving
wheel, the ASR system cuts in automatically
braking the skidding wheel, with an effect
similar to that of a self-locking differential.The action of the ASR system is particularly
helpful under the following conditions:
– Skidding of the inner wheel on a bend,
due to the effect of the dynamic changes of
the load or over-accelerating.
– Excessive power transmitted to the
wheels, also in relation to the conditions of
the road surface.
– Acceleration on slippery, snowy or icy
surfaces.
– In the case of loss of grip on a wet sur-
face (aquaplaning).
CUTTING IN OF THE VDC
SYSTEMThe cutting in of the VDC system is indi-
cated by the flashing of the warning lightá
on the instrument cluster, to inform the
driver that the car is in critical conditions of
stability and grip.
TURNING ON THE ASR
FUNCTIONThe ASR function turns on automatically
each time the engine is started.
When travelling it is possible to switch the
system off and on again pressing the switch
(A-fig. 171
) on the centre console.
Function disconnection is shown by the led
on the ASR button being turned on. If the
function is turned off while travelling, it will
turn on again automatically the next time
the engine is started.
WARNING When driving on snow, with
snow chains fitted, if may be helpful to switch
off the ASR function: in these conditions in
fact, skidding of the driving wheels when
moving off helps to obtain better traction.
fig. 171
A0B0557m

GETTING TO KNOW YOUR CAR
182
EOBD SYSTEMThe EOBD (European On Board Diagnosis)
system fitted in the car conforms with the
98/69/EC (EURO 3) Directive and the
2001/1/EC Directive, level B (EURO4) for
2.0 JTS, 2.0 JTS Selespeed and JTD 20V
Multijet versions.
This system continuously monitors the
components of the vehicle related to emis-
sions; it also indicates, when the warning
light
U
comes on on the instrument panel
(together with the message + symbol
shown by the display) that the components
in question are in poor conditions.
The objective is the following:
– to keep under control the efficiency of
the system;
– to indicate when a malfunction causes
an increase in the emissions beyond the
threshold established by European regula-
tions;
– to indicate the need to replace the de-
teriorated components.
The system also has a diagnostic connec-
tor, which can be interfaced with adequate in-
struments, that enables the error codes stored
in the control unit to be read, together with
a series of specific parameters concerning the
operation and diagnosis of the engine.This check can also be made by the traf-
fic control agents.
If, when the ignition key
is turned to MAR, the
U
warning light does not
come on or if, when driving, it
lights up and emits a fixed light or
a flashing one (together with the
message + symbol shown by the
display), contact an Alfa Romeo
Authorized Service Station as soon
as possible. The operation of the
U
warning light can also be
checked by means of special equip-
ment available to the traffic con-
trol officers. Comply with the reg-
ulations in force in country where
you drive your car.
WARNINGAfter the problem has beel
resolved, to completely check the system,
the Alfa Romeo Authorized Services must
carry out tests on a test bench and, if nec-
essary, road tests that could be long.
WARNING LIGHT ON
INSTRUMENT PANELWhen the ignition key is turned to MAR,
the dial warning light
á
comes on but must
go out after a few seconds.
If the warning light does not go out, or if it
stays on (together with the message + sym-
bol on the display and the coming on of the
ASR button led) when the vehicle is running,
contact Alfa Romeo Authorized Services.
The flashing of the warning lamp when the
vehicle is running indicates the actuation of
the VDC system.
VDC system failure warning
In the event of a failure the VDC system
disengages automatically and the
á
warn-
ing light on the instrument cluster turns on
glowing steadily (together with the message
+ symbol shown on the display and the com-
ing on of the ASR button led).
In the event of a VDC system failure the
car behaves like a vehicle not fitted with this
system: in any case it is advisable to con-
tact Alfa Romeo Authorized Services as soon
as possible.