Triggering - Mercedes-Benz 2013 C-Class W204 Sedan Owner's Manual

occupants must wear their seat belt cor-
rectly at all times, even if the vehicle is
equipped with airbags. The airbags are not
deployed in all types of accidents. For
example, if the protective capacity of cor-
rectly fastened seat belts is not increased
by deploying the airbags, the airbags will
not deploy. Airbag deployment only pro-
vides increased protection if the seat belt
is worn correctly because:
the seat belt helps to keep the vehicle
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occupant in the best position in relation
to the airbag.
in a head-on collision, for example, the
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seat belt prevents the vehicle occupant
from being propelled towards the point
of impact. It can thus reduce the risk of
injury.
In accidents in which an airbag is deployed,
it provides increased protection only if the
seat belt is worn correctly.
SRS (Supplemental Restraint System)
Introduction
SRS consists of:
the 6 SRS warning lamp
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airbags
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airbag control unit (with crash sensors)
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belt tensioners
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belt force limiters
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SRS reduces the risk of occupants coming
into contact with the vehicle's interior in the
event of an accident. It can also reduce the
forces to which occupants are subjected dur-
ing an accident.
SRS warning lamp
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WARNING
If SRS is malfunctioning, child restraint sys-
tem components may be triggered uninten-
tionally or might not be triggered at all in the
event of an accident with a high rate of vehicle
Occupant safety
deceleration. There is an increased risk of
injury, possibly even fatal.
Have SRS checked and repaired immediately
at a qualified specialist workshop.
SRS functions are checked regularly when
you switch on the ignition and when the
engine is running. Therefore, malfunctions
can be detected in good time.
The 6 SRS warning lamp in the instrument
cluster lights up when the ignition is switched
on. It goes out no later than a few seconds
after the engine is started.
The SRS components are in operational read-
iness when the 6 SRS warning lamp goes
out while the engine is running.
A malfunction has occurred if:
the 6 SRS warning lamp does not light
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up when the ignition is switched on
the engine is running and the 6 SRS
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warning lamp does not go out after a few
seconds
the engine is running and the 6 SRS
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warning lamp lights up again
Triggering of belt tensioners and air-
bags
During the first stage of a collision, the airbag
control unit evaluates important physical
data relating to vehicle deceleration or accel-
eration, such as:
duration
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direction
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magnitude
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Based on the evaluation of this data, the air-
bag control unit pre-emptively triggers the
belt tensioners in the first stage.
i The front belt tensioners can only be trig-
gered if the seat belt tongues on the front
seats are correctly engaged in the seat belt
buckles.
If there is an even higher rate of vehicle decel-
eration or acceleration in a longitudinal direc-
tion, the front airbags are also deployed.
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