Mercedes-Benz 2013 M Class - Manual (Page 61)

Emergency Tensioning Devices, seat
belt force limiter
G WARNING
Pyrotechnic Emergency Tensioning Devices
that have been deployed must be renewed.
For your safety, when disposing of Emergency
Tensioning Devices, always observe the
safety instructions. These are available from
any authorized Mercedes-Benz Center.
The PRE-SAFE
® system has electrically
operated reversible pre-tensioners that do
not require replacement after activation.
! If the front-passenger seat is not
occupied, do not engage the seat belt
tongue in the buckle on the front-
passenger seat. Otherwise, the Emergency
Tensioning Device could be triggered in the
event of an accident.
X In order to ensure that the pyrotechnic
Emergency Tensioning Devices have not
been triggered, always have the seat belts
checked after an accident.
If the Emergency Tensioning Devices have
been triggered, they must be replaced.
The front seat belts and the outer seat belts
in the rear are equipped with Emergency
Tensioning Devices and belt force limiters.
The ETDs on the driver's and front-passenger
seat consist of pyrotechnic belt buckle
tensioners and belt anchor tensioners that
are triggered together. The belt buckle
tensioner is mounted on the B-pillar and the
belt anchor installing is mounted on the side
of the seat. After deploying, both tensioners
must always be replaced.
The ETDs tighten the seat belts in an accident,
pulling them close against the body.
The ETDs do not correct incorrect seat
positions or incorrectly fastened seat belts.
The ETDs do not pull vehicle occupants back
towards the backrest.
When triggered, seat belt force limiters help
to reduce the peak force exerted by the seat
belt on the vehicle occupant.
The belt force limiters for the front seats are
synchronized with the front air bags, which
take on a part of the deceleration force. This
results in the force exerted on the occupant
being distributed over a greater area.
The ETDs can only be activated when:
R
the ignition is switched on.
R
the restraint systems are operational; see
"SRS warning lamp" (
Y page 43).
R
the belt tongue is engaged in the buckle on
each of the lap-shoulder belts in the front.
R
the front-passenger seat is occupied and
the belt tongue is engaged in the buckle on
the front-passenger side
The ETDs on the outside seats in the rear
compartment are triggered independently of
the lock status of the seat belts.
The ETDs are triggered depending on the type
and severity of an accident:
R
if, in the event of a head-on or rear-end
collision, the vehicle decelerates or
accelerates rapidly in a longitudinal
direction during the initial stages of the
impact
R
if, in the event of a side impact, on the side
opposite the impact the vehicle
decelerates or accelerates rapidly in a
lateral direction
R
if, in certain situations where the vehicle
overturns, the system determines that it
can provide additional protection
If the ETDs are deployed, you will hear a bang,
and a small amount of powder may also be
released. Only in rare cases will the bang
affect your hearing. The powder that is
released generally does not constitute a
health hazard. The 6 SRS warning lamp
lights up.
Occupant safety
59
Safety
Z