50 Safety
Occupant safety
Triggering ofbelt tensioners, belt force limiters and
airbags
In the event ofa collision, the sensor in the
airbag contro lunit evaluates important
physical data, such as duration, direction
and rate of veh icle deceleration or acceler-
ation. Based on this evaluation and pre-
emptively, the belt tensioners are the first
to be triggered by the airb agcontrol unit in
a collis ion with longi tudinal deceleration as
a function of the rate of vehicle decelera-
tion.
The front airbags are not triggered unless a
second activation threshold is reached, i.e.
an even higher rate of vehicle deceleration
in the longitudinal direction is exceeded. i
Thefront airbag on the front-passenger side
is only tri ggered if:
! the front-passenger seat oc cupancy sensor
has detected that the seat is occupied
! the PASSENGER AIRBAG OFF warning lamp
onthe centre console is not lit (
=page 64)
The belt tensioners are only activated if the seat
belt buck le tongue is correctl yengaged in the
se at belt buckle.
Criteria for the activation of belt
tensioners and airbags
To determine whether it is necessary to
activ ate a belt tensioner or airbag, the air-
bag control unit evaluates the duration and
direction of vehicle deceleration or accel-
eration during the initial phase of the colli-
sion.
The activation thresholds for the belt ten-
sioners and the airbags are variable and
are adapted in accordance with the rate of
ve hicle deceleration. This process ispre-
emptive in nature as airbag deployment
must take place during the impact and not
at the end of the collision. G
Risk of inju ry A malfu
nction has occurred if the 1
warning lamp:
! doesnot com eon when yousw itchon
th eignition
! does not go out after a few seconds
when the engine is running
! comes on again
Individ ual systems could beactivated inad-
verte ntly or may not be triggered at all in the
event of an accident with a high rate of vehi-
cle deceleration. Ifthis happens, have the
SRS system checked and repaired immedi-
ately at a qualified specialist wor kshop
wh ich has the necessary specialist know-
ledg eand tools to carry out the work
require d.
Mercedes-Benz recomme nds that youuse a
Mercedes-Benz Service Centre for this pur-
pose. In particular, work relevant to safety
or on safety-re lated systems must be car-
ried out at a qualified specialist workshop. 209en_d2.boo Seite
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