An Emergency Tensioning Device can only be
triggered, if:
R
the ignition is switched on
R
the components of the restraint system are
operational. You can find further information
under "Restraint system warning lamp"
(
Y
page 41)
R
the seat belt buckle tongue has engaged in
the belt buckle of the respective seat
If the restraint system control unit detects a
more severe accident, further components of
the restraint system are activated independ-
ently of each other in certain frontal collision
situations:
R
Front air bags as well as driver's and front-
passenger knee bags
Depending on the person in the front-
passenger seat, the front-passenger front air
bag is either enabled or disabled. The front-
passenger front air bag can be deployed in an
accident only if the PASSENGER AIR BAG OFF
indicator lamp is off. Observe the information
on the PASSENGER AIR BAG indicator lamps
(
Y
page 41).
Your vehicle has two-stage front air bags.
The activation threshold of the Emergency
Tensioning Devices and the air bags is deter-
mined by evaluating the rate of vehicle decel-
eration or acceleration which occurs at various
points in the vehicle. This process is pre-emp-
tive in nature. Deployment should take place
in good time at the start of the collision.
The rate of vehicle deceleration or accelera-
tion and the direction of the force are essen-
tially determined by:
R
the distribution of forces during the collision
R
the collision angle
R
the deformation characteristics of the vehi-
cle
R
the characteristics of the object with which
the vehicle has collided
Factors which can only be seen and measured
after a collision has occurred do not play a
decisive role in the deployment of an air bag.
Nor do they provide an indication of air bag
deployment.
The vehicle can be deformed considerably,
without an air bag being deployed. This is the
case if only parts which are relatively easily
deformed are affected and the rate of deceler-
ation is not high. Conversely, air bags may be
deployed even though the vehicle suffers only
minor deformation. This is the case if, for
example, very rigid vehicle parts such as longi-
tudinal body members are hit, and sufficient
deceleration occurs as a result.
If the restraint system control unit detects a
side impact or if the vehicle rolls over, the
applicable components of the restraint system
are deployed independently of each other
depending on the apparent type of accident.
R
Side impact air bag on the side of impact,
independently of the Emergency Tensioning
Device and the use of the seat belt on the
driver's seat
The side impact air bag on the front
passenger side deploys under the following
conditions:
-
the OCS system detects that the front
passenger seat is occupied or
-
the seat belt buckle tongue is engaged in
the belt buckle of the front passenger
seat
R
Head bag on the side of impact, independ-
ently of the use of the seat belt and inde-
pendently of whether the front-passenger
seat is occupied
R
Emergency Tensioning Devices, if the sys-
tem determines that deployment can offer
additional protection in this situation
R
Head bags on the driver's and front-
passenger side in certain situations when
the vehicle rolls over, if the system deter-
mines that deployment can offer additional
protection to that provided by the seat belt
i
Not all air bags are deployed in an acci-
dent. The different air bag systems work
independently of each other.
How the air bag system works is determined
by the severity of the accident detected,
especially the vehicle deceleration or accel-
eration and the apparent type of accident:
R
Head-on collision
R
Side impact
R
Rollover
54
Occupant safety
Safe
ty
Summary of Contents for SL 450 2019
Page 330: ...328...
