2001 MERCEDES-BENZ C320 belt

56 Restraint systems
Te ch n i c a l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
Seat belt nonusage warning system
With the electronic key in starter switch position 2, a
warning sounds for a short time if the driver’s seat belt
is not fastened.
Automatic comfort-fit seat belt:
An automatic comfort-fit feature for driver and front
passenger seat belt is activated when the electronic key
in the starter switch is turned to position 1 or 2.
The retraction force of the inertia reel is reduced,
increasing the level of seat belt comfort.
Note:
For cleaning and care of the seat belts see page 345.
Wa r n i n g !
Never ride in a moving vehicle with the backrest
reclined. Sitting in an excessively reclined position
can be dangerous. You could slide under the seat
belt in a collision. If you slide under it, the belt
would apply force at the abdomen or neck. That
could cause serious or even fatal injuries. The
backrest and seat belt provide the best restraint
when the wearer is in an upright position and the
belt is properly positioned on the body.

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data Instruments
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Wa r n i n g !
Failure to wear and properly fasten and position
your seat belt greatly increases your risk of
injuries and their likely severity in an accident.
You and your passengers should always wear seat
belts.If you are ever in an accident, your injuries can be
considerably more severe without your seat belt
properly buckled. Without your seat belt buckled,
you are much more likely to hit the interior of the
vehicle or be ejected from it. You can be seriously
injured or killed.In the same crash, the possibility of injury or death
is lessened if you are wearing your seat belt.
Wa r n i n g !
Never let more people ride in the vehicle than there
are seat belts available. Be sure everyone riding in
the vehicle is correctly restrained with a separate
seat belt.

58 Restraint systems
Te ch n i c a l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index
Fastening seat belts
1Latch plate
2Buckle
3Release button
Push latch plate (1) into buckle (2) until it clicks. Do not
twist the belt. A twisted seat belt may cause injury.The lap belt should be positioned as low as possible on
your hips and not across the abdomen.
Tighten the lap portion to a snug fit by pulling shoulder
portion up.
The shoulder portion of the seat belt must be pulled
snug and checked for snugness immediately after
engaging it.
Adjust seat belt so that shoulder portion is located as
close as possible to the middle of your shoulder (it
should not touch the neck). For this purpose, you can
adjust the height of the belt outlet.
Wa r n i n g !
Always fasten your seat belt before driving off.
Always make sure your passengers are properly
restrained – even those sitting in the rear.

59 Restraint systems
Te ch n i c a l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index 4Button for belt outlet height adjustment
To raise, slide belt outlet upward.
To lower, press button (4) and slide belt outlet
downward.Operation of seat belts
The inertia reel stops the belt from unwinding during
sudden stops or when quickly pulling on the belt.
The locking function of the reel may be checked by
quickly pulling out the belt.
Adjust seat belt so that shoulder portion is located as
close as possible to the middle of your shoulder (it
should not touch the neck).
Caution!
For safety reasons, avoid adjusting the seat or seat back
into positions which could affect the correct seat belt
positioning.
Unfastening of seat belts
Press release button (3) in the belt buckle (2).
Allow the retractor to completely rewind the seat belt by
guiding the latch plate (1).

60 Restraint systems
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data Instruments
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Wa r n i n g !
USE SEAT BELTS PROPERLY.• Seat belts can only work when used properly.
Never wear seat belts in any other way than as
described in this section, as that could result
in serious injuries in case of an accident.• E ach oc c upan t s houl d wear t hei r s ea t bel t a t al l
times, because seat belts help reduce the
likelihood of and potential severity of injuries
in accidents, including rollovers. The
integrated restraint system includes “SRS”
(driver airbag, front passenger airbag, side
impact airbags, head protection window
curtain airbags for side windows), “ETR” (seat
belt emergency tensioning retractors), and
front seat knee bolsters. The system is
designed to enhance the protection offered to
properly belted occupants in certain frontal
(front airbags) and side (side impact and
window curtain airbags) impacts which exceed
preset deployment thresholds.
• Never wear the shoulder belt under your arm,
against your neck or off your shoulder. In a
crash, your body would move too far forward.
That would increase the chance of head and
neck injuries. The belt would also apply too
much force to the ribs or abdomen, which
could severely injure internal organs such as
your liver or spleen.• Never wear belts over rigid or breakable
objects in or on your clothing, such as
eyeglasses, pens, keys etc., as these might
cause injuries.• Position the lap belt as low as possible on your
hips and not across the abdomen. If the belt is
positioned across your abdomen, it could cause
serious injuries in a crash.• Each seat belt should never be used for more
than one person at a time. Do not fasten a seat
belt around a person and another person or
other objects.• Belts should not be worn twisted. In a crash,
you wouldn’t have the full width of the belt to
manage impact forces. The twisted belt against
your body could cause injuries.

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• Pregnant women should also use a lap-
shoulder belt. The lap belt portion should be
positioned as low as possible on the hips to
avoid any possible pressure on the abdomen.• Never place your feet on the instrument panel
or on the seat. Always keep both feet on the
floor in front of the seat.Wa r n i n g !
USE CHILD RESTRAINTS PROPERLY.Children 12 years old and under must never ride in
the front seat, except in a Mercedes-Benz
authorized BabySmart
TM compatible child seat,
which operates with the BabySmart
TM system
installed in the vehicle to deactivate the passenger
front airbag when it is properly installed.
Otherwise they will be struck by the airbag when it
inflates in a crash. If this happens, serious or fatal
injury will result.
According to accident statistics, children are safer
when properly restrained in the rear seating
positions than in the front seating positions.
Infants and small children must ride in the back
seats and be seated in an appropriate infant or
child restraint system, which is properly secured
with the vehicle’s seat belt, fully in accordance
with the child seat manufacturer’s instructions.A child’s risk of serious or fatal injuries is
significantly increased if the child restraints are
not properly secured in the vehicle and the child is
not properly secured in the child restraint.Children too big for child restraint systems must
ride in back seats using regular seat belts. Position
shoulder belt across chest and shoulder, not face or
neck. A booster seat may be necessary to achieve
proper belt positioning.

63 Restraint systems
Te ch n i c a l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index Supplemental Restraint System (SRS)
Airbags are intended as a supplement to seat belts.
Airbags alone cannot protect as well as airbags plus
seat belts in impacts for which the airbags were
designed to operate, and do not afford any protection
whatsoever in crashes for which the airbags are not
designed to deploy.
The SRS uses two crash severity levels (thresholds) to
activate either the emergency tensioning retractor (ETR)
or front airbag or both. Activation depends on the
direction and severity of the impact exceeding the
preset thresholds and whether the seat belt is fastened.Seat belt fastened
•first threshold exceeded: ETR activates
•second threshold exceeded: airbag also activates
Seat belt not fastened
Front seats:
•first threshold exceeded: airbag activates, not ETR
Rear outer seats:
•first threshold exceeded: ETR activates
Driver and front passenger and rear outer seat systems
operate independently of each other.

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data Instruments
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Emergency tensioning retractor (ETR)
The seat belts for the front and rear outer seats are
equipped with emergency tensioning retractors. These
tensioning retractors are located in each belt’s inertia
reel and become operationally ready with the electronic
key in starter switch position 1 or 2.
The emergency tensioning retractors are designed to
activate only when the seat belts are fastened during
frontal impacts exceeding the first threshold of the SRS
and in rear impacts exceeding a preset severity level.They remove slack from the belts in such a way that the
seat belts fit more snugly against the body restricting its
forward movement as much as possible.
In cases of other frontal impacts, angled impacts, roll-
overs, certain side impacts, or other accidents without
sufficient frontal or rear impact forces, the emergency
tensioning retractors will not be activated. The driver
and passengers will then be protected by the fastened
seat belts and inertia reel in the usual manner.