Mercedes-Benz A Series Owner's Manual page 41

Safety
Occupant safety
airbag deployment must take place during
the impact and must be adapted to provide
calculated, additional protection for the
vehicle occupants. Not all airbags are
deployed in an accident.
The different airbag systems work inde-
pendently of each other. However, the
deployment of each individual system will
depend on the type of accident determined
by the control system in the first stages of
the collision (head-on collision, side impact
and overturn) and the extent of the acci-
dent (in particular, the vehicle's rate of
deceleration or acceleration).
The rate of vehicle deceleration or accelera-
tion and the direction of the force are basi-
cally determined by:
the distribution of forces during the colli-
R
sion
the collision angle
R
the deformation characteristics of the vehi-
R
cle
the characteristics of the object with which
R
the vehicle has collided, e.g. the other vehi-
cle
Factors which can only be seen and measured
after a collision has occurred do not play a
38
decisive role in the deployment of an airbag,
nor do they provide an indication of it.
The vehicle may be deformed significantly,
e. g. on the bonnet or the wing, without an
airbag being deployed. This is the case if only
parts which are relatively easily deformed are
affected and the necessary deceleration does
not occur. Conversely, airbags may be
deployed even though the vehicle suffers only
minor deformations. This is the case if, for
example, very rigid vehicle parts such as lon-
gitudinal body members are affected and suf-
ficient deceleration occurs as a result.
Belt tensioners, belt force limiters
The front seat belts and the outer seat belts
in the rear are equipped with belt tensioners.
If the seat belt is also equipped with a belt
force limiter, the force exerted by the seat
belt on the seat occupant is reduced.
Belt tensioners tighten the seat belts in an
accident, pulling them close against the body.
i
Belt tensioners do not correct incorrect
seat positions or incorrectly fastened seat
belts.
Belt tensioners do not pull occupants back
towards the backrest.
The front belt force limiters are synchronised
with the front airbags, which distribute the
forces exerted by the belt force limiters on
the occupant over a greater area.
When the ignition is switched on, the belt ten-
sioner is triggered:
only if the restraint systems are operational
R
(the 1 warning lamp lights up after the
ignition is switched on and goes out once
the engine is running) ( page 37)
Y
in the event of a head-on or rear-end colli-
R
sion if the vehicle decelerates or acceler-
ates rapidly in a longitudinal direction dur-
ing the initial stages of impact
If the airbags are deployed, you will hear a
bang and a small amount of powder may also
be released. Only in rare cases will the bang
affect your hearing. The powder that escapes
does not generally constitute a health hazard.
The 1 warning lamp lights up.
G Risk of injury
If the seat belt tensioners have been trig-
gered, they provide no additional protec-
tion in the event of another accident. There-
fore, have belt tensioners which have been
triggered replaced at a qualified specialist
workshop.