Mercedes-Benz Sprinter Operating Instructions Manual page 52

Occupant safety
50
may cause short-term breathing difficulties in
people with asthma or other respiratory prob-
lems. To avoid this, you may wish to get out of
the vehicle or open the windows as soon as it
is safe to do so.
Air bags and pyrotechnic Emergency Tension-
ing Devices (ETDs) contain perchlorate mate-
rial, which may require special handling and
regard for the environment. National guide-
lines must be observed during disposal. In
California, see www.dtsc.ca.gov/
HazardousWaste/Perchlorate/
index.cfm.
Method of operation
During the first stage of a collision, the
restraint system control unit evaluates impor-
tant physical data relating to vehicle deceler-
ation or acceleration, such as:
duration
R
direction
R
intensity
R
Based on the evaluation of this data, the
restraint system control unit triggers the
Emergency Tensioning Devices during a fron-
tal or rear collision.
An Emergency Tensioning Device can only be
triggered, if:
the ignition is switched on.
R
the components of the restraint system are
R
operational; see "Restraint system warning
lamp" ( page 42)
Y
the belt tongue is engaged in the buckle on
R
the respective front-passenger seat
Vehicles with two seats on the front-
passenger side: the Emergency Tensioning
Device on the inner front-passenger seat is
triggered independently of the lock status of
the seat belt.
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:
Front air bags
R
Window curtain air bag on the side of
R
impact
The activation threshold of the Emergency
Tensioning Devices and the air bag are deter-
mined by evaluating the rate of vehicle decel-
eration or acceleration which occurs at vari-
ous points in the vehicle. This process is pre-
emptive 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:
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
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 decel-
eration 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 lon-
gitudinal body members are hit, and sufficient
deceleration occurs as a result.