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 44)
R
the belt tongue is engaged in the buckle on
the respective front-passenger seat
The Emergency Tensioning Devices in the rear
compartment are triggered independently of the
lock status of the seat belts.
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
R
Coupe:
Window curtain air bag, if the system deter-
mines that deployment can offer additional
protection to that provided by the seat belt
R
Cabriolet:
Head bag, if the system determines that
deployment can offer additional protection to
that provided by the seat belt
The front-passenger front air bag is activated or
deactivated depending on the person on the
front-passenger seat. The front-passenger front
air bag can only deploy in an accident if the
PASSENGER AIR BAG ON indicator lamp is lit.
Observe the information on the PASSENGER AIR
BAG indicator lamps (
Y
page 44).
Your vehicle has two-stage front air bags. During
the first deployment stage, the front air bag is
filled with propellant gas to reduce the risk of
injuries. The front air bag is fully deployed with
the maximum amount of propellant gas if a sec-
ond deployment threshold is reached within a
few milliseconds.
The activation threshold of the Emergency Ten-
sioning Devices and the air bag are determined
by evaluating the rate of vehicle deceleration or
acceleration which occurs at various 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 acceleration
and the direction of the force are essentially
determined by:
R
the distribution of forces during the collision
R
the collision angle
R
the deformation characteristics of the vehicle
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 deci-
sive role in the deployment of an air bag. Nor do
they provide an indication of air bag deploy-
ment.
The vehicle can be deformed considerably, with-
out an air bag being deployed. This is the case if
only parts which are relatively easily deformed
are affected and the rate of deceleration is not
high. Conversely, air bags may be deployed even
though the vehicle suffers only minor deforma-
tion. This is the case if, for example, very rigid
vehicle parts such as longitudinal body mem-
bers are hit, and sufficient deceleration occurs
as a result.
If the control unit of the restraint system detects
a side impact or a vehicle rollover, the relevant
components of the restraint system are activa-
ted separately depending on the anticipated
type of accident.
R
Side impact air bags on the side of impact,
independently of the Emergency Tensioning
Device and the use of the seat belt on the
driver's seat and in the rear compartment
seats
The side impact air bag on the front-
passenger side (front) deploys under the fol-
lowing conditions:
-
the OCS system detects that the front-
passenger seat is occupied or
-
the belt tongue is engaged in the belt
buckle of the front-passenger seat
R
Coupe:
Window curtain air bag on the side of impact,
independently of the use of the seat belt and
independently of whether the front-
passenger seat is occupied
R
Cabriolet:
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
58
Occupant safety
Safety
