Mercedes-Benz S-Coupe 2015 - Manual (Page 60)

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
Window curtain air bag, if the system deter-
mines 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 indi-
cator lamp is lit. Observe the information on
the PASSENGER AIR BAG indicator lamps
(
Y
page 43).
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 pro-
pellant gas if a second deployment threshold
is reached within a few milliseconds.
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:
R the distribution of forces during the colli-
sion
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 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.
If the restraint system control unit detects a
side impact or that the vehicle is rolling over,
the relevant restraint system components are
activated independently of one another
depending on the apparent type of accident.
If the system determines a need for additional
protection for the vehicle occupants, the
Emergency Tensioning Devices are triggered.
R Side impact air bags on the side of impact,
independently of the Emergency Tension-
ing Device and the use of the seat belt on
the driver's seat and in the rear compart-
ment seats
The side impact air bag on the front-
passenger side (front) deploys in the fol-
lowing situations:
- 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 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 Window curtain air bags on the driver's and
front-passenger side in certain situations
when the vehicle rolls over, if the system
determines that deployment can offer addi-
tional 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.
58
Occupant safety
Safety