2001 MERCEDES-BENZ C240 Owner's Manual

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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.

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Front airbags1Driver airbag
2Front passenger airbag
The most effective occupant restraint system yet
developed for use in production vehicles is the seat belt.
In some cases, however, the protective effect of a seat
belt can be further enhanced by an airbag.
In conjunction with wearing the seat belts, the driver
and front passenger airbags can provide increased
protection for the driver and front passenger in certain
frontal impacts exceeding preset thresholds.
Sid e imp act an d head pro tec ti on win d ow curtai n air bags
can provide increased protection to belted occupants on
the impacted side of the vehicle in side impacts
exceeding its preset threshold.
The operational readiness of the airbag system is
verified by the indicator lamp “SRS” in the instrument
cluster when turning the electronic key in starter switch
to position 1 or 2. If no fault is detected, the lamp will go
out after approximately 4 seconds; after the lamp goes
out, the system continues to monitor the components
and circuitry of the airbag system and will indicate a
malfunction by coming on again. If the lamp does not
P91.60-2252-27

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come on at all or if it fails to extinguish after
approximately 4 seconds or if it comes on thereafter,
a malfunction in the system has been detected.
The following system components are monitored or
undergo a self-check: crash-sensor(s), airbag ignition
circuits, front seat belt buckles, emergency tensioning
retractors, seat sensor.
Initially, when the electronic key is turned from starter
switch position 0 to position 1 or 2, malfunctions in the
crash sensor are detected and indicated (the “SRS”
indicator lamp stays on longer than 4 seconds or does
not come on).
Have the system checked at your authorized
Mercedes-Benz Center immediatelyIn the operational mode, after the indicator lamp has
gone out following the initial check, interruptions or
short circuits in the airbag ignition circuit and in the
driver and front passenger seat belt buckle harnesses,
and low voltage in the entire system are detected and
indicated.
Note:
See page 271 for information on the supplemental
restraint system (SRS) indicator lamp.
Wa r n i n g !
In the event a malfunction of the “SRS” is indicated
as outlined above, the “SRS” may not be
operational. For your safety, we strongly
recommend that you visit an authorized
Mercedes-Benz Center immediately to have the
system checked; otherwise the “SRS” may not be
activated when needed in an accident, which could
result in serious or fatal injury, or it might deploy
unexpectedly and unnecessarily which could also
result in injury.

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cluster displayPractical hints Car care Index The driver and passenger front airbags are designed to
activate only in certain frontal impacts exceeding a
preset threshold. The front passenger airbag deploys
only if the front passenger seat is occupied and the
ü indicator lamp in the center console is not
illuminated.Note:
Heavy objects on the front passenger seat can appear to
the “SRS” to indicate the presence of an occupant in
that seat which causes the passenger front airbag to
deploy in a crash exceeding the appropriate threshold.

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Side impact airbags, window curtain airbags
3Side impact airbags
4Window curtain airbagsSide impact airbags
The side impact airbags are designed to activate only in
certain side impacts exceeding a preset threshold. Only
the side impact airbags on the impacted side of the
vehicle deploy.
The side impact airbag for the front passenger deploys
only if the front passenger seat is occupied.
Side impact airbags operate best in conjunction with a
properly positioned and fastened seat belt.
Note:
Heavy objects on front passenger seat can cause the
front passenger side impact airbag to deploy in a crash.
Window curtain airbag
The head protection window curtain airbags afford
greater protection against injuries to the head and
upper body. They fill up in the area between the A and
C pillars (see arrows) between the side windows and an
occupant’s head.

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cluster displayPractical hints Car care Index The window curtain airbags are designed to activate
only in certain side impacts exceeding a preset
threshold. Only the head protection window curtain
airbag on the impacted side of the vehicle deploys.Important!
Airbags are designed to activate only in certain
frontal (front airbags) impacts, or side (side impact
and head protection window curtain airbags)
impacts which exceed preset thresholds.
Only during these types of impacts, if of sufficient
severity to meet the deployment thresholds, will
they provide their supplemental protection.
The driver and passenger should always wear their
seat belts, otherwise it is not possible for the airbags
to provide their supplemental protection.
In cases of other frontal impacts, angled impacts,
roll-overs, other side impacts, rear collisions, or
other accidents, the airbags will not be activated.
The driver and passengers will then be protected by
the fastened seat belts.
We caution you not to rely on the presence of the
airbags in order to avoid wearing your seat belt.

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Your vehicle was originally equipped with airbags
which are designed to activate in certain impacts
exceeding a preset threshold to reduce the potential
and severity of injury. It is important to your safety
and that of your passenger that you replace deployed
airbags and repair any malfunctioning airbags to
ensure the vehicle will continue to provide crash
protection for occupants.
Wa r n i n g !
Airbags are designed to reduce the potential of
injury in certain frontal (front airbags) impacts, or
side (side impact and head protection window
curtain airbags) impacts which may cause
significant injuries, however, no system available
today can totally eliminate injuries and fatalities.The activation of the “SRS” temporarily releases a
small amount of dust from the airbags. This dust,
however, is neither injurious to your health, nor
does it indicate a fire in the vehicle. The dust might
cause some temporary breathing difficulty for
people with asthma or other breathing trouble. To
avoid this, you may wish to get out of the vehicle as
soon as it is safe to do so. If you have any breathing
difficulty but cannot get out of the vehicle after the
airbag inflates, then get fresh air by opening a
window or door.The service life of the airbags extends to the date
indicated on the label located on the driver side
door latch post. To provide continued reliability
after that date, they should be inspected by an
authorized Mercedes-Benz Center at that time and
replaced when necessary.
Wa r n i n g !
To reduce the risk of injury when the front airbags
inflate, it is very important for the driver and front
passenger to always be in a properly seated
position and to wear your seat belt.For maximum protection in the event of a collision
always be in normal seated position with your back
against the backrest. Fasten your seat belt and
ensure that it is properly positioned on your body.Since the airbag inflates with considerable speed
and force, a proper seating and hands on steering
wheel position will help to keep you at a safe
distance from the airbag. Occupants who are
unbelted, out of position or too close to the airbag
can be seriously injured by an airbag as it inflates
with great force in the blink of an eye:

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• Sit properly belted in an upright position with
your back against the backrest.• Adjust the driver seat as far as possible
rearward, still permitting proper operation of
vehicle controls. The distance from the center
of the driver’s breastbone to the center of the
airbag cover on the steering wheel must be at
least ten inches (25 cm) or more. You should be
able to accomplish this by a combination of
adjustments to the seat and steering wheel. If
you have any problems, please see your
authorized Mercedes-Benz Center.• Do not lean with your head or chest close to the
steering wheel or dashboard.• Keep hands on the outside of steering wheel
rim. Placing hands and arms inside the rim
can increase the risk and potential severity of
hand / arm injury when driver front airbag
inflates.• Adjust the front passenger seat as far as
possible rearward from the dashboard when
the seat is occupied.
• Occupants, especially children, should never
lean their heads in the area of the door where
the side airbag inflates. This could result in
serious injuries or death should the airbag be
triggered.• Children 12 years old and under must never
ride in the front seat, except in a
Mercedes-Benz authorized Baby Smart
TM
compatible child seat, which operates with the
BabySmart
TM system installed in the vehicle to
deactivate the passenger side 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
can result.
Failure to follow these instructions can result in
severe injuries to you or other occupants.