MERCEDES-BENZ SL-Class 2001 R129 Repair Manual

57 Restraint systems
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• Never wear the shoulder belt under your arm,
against you 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.• Each seat belt must 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.• 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 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
this vehicle, 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 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 will
result.
Infants and small children must 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.Adjust the passenger seat as far as possible
rearward from the dashboard when the seat is
occupied.

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BabySmart
TM airbag deactivation system
Special BabySmart
TM compatible child seats, designed
for use with the Mercedes-Benz system and available at
any authorized Mercedes-Benz Center are required for
use with the BabySmart
TM airbag deactivation system.
With the special child seat properly installed, the
passenger side front airbag will not deploy. The 7
indicator lamp located in the dashboard will be
illuminated, except with key removed or in steering lock
position 0. The system does not deactivate the door
mounted side impact airbag.Self-test BabySmart
TM
without special child seat installed
After turning key in steering lock to position 1 or 2, the
7 indicator lamp located in the dashboard comes on
for approx. 6 seconds and then extinguishes.
If the indicator lamp should not come on or is
continuously lit, the system is not functioning. You must
see an authorized Mercedes-Benz Center before seating
any child on the front passenger seat.BabySmart
TM is a trademark of Siemens Automotive Corp.
Wa r n i n g !
The BabySmart
TM airbag deactivation system will
ONLY work with a special child seat designed to
operate with it. It will not work with child seats
which are not BabySmart
TM compatible.
Never place anything between seat cushion and
child seat (e.g. pillow), since it reduces the
effectiveness of the deactivation system.Follow the manufacturer’s instructions for
installation of special child seats.The passenger front airbag will not deploy only if
the 7 indicator lamp remains illuminated.
Please be sure to check the indicator every time
you use the special system child seat.
Should the light go out while the restraint is
installed, please check installation. If the light
remains out, do not use the BabySmart
TM restraint
to transport children on the front passenger seat
until the system has been repaired.

59 Restraint systems
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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
• first threshold exceeded:
airbag activates, but not ETR
Driver and passenger systems operate independently of
each other.Emergency tensioning retractor (ETR)
The seat belts are equipped with emergency tensioning
retractors. These tensioning retractors are located in
each belt’s inertia reel and become operationally ready
with the key in steering lock position 1 or 2.
The emergency tensioning retractors are designed to
activate only when the seat belts are fastened during
frontal and front-angled impacts and rear 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, rollovers, certain side
impacts, rear collisions or other accidents without
sufficient frontal or rear impact forces, the emergency
tensioning retractors will not be activated. The driver
and passenger will then be protected by the fastened
seat belts and inertia reel in the usual manner.
For seat belt and emergency tensioning retractor safety
guidelines see page 67.

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Airbags 1Driver airbag
2Passenger front airbag
3Side impact airbags
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 passenger airbags can provide increased protection
for the driver and passenger in certain frontal impacts
exceeding preset thresholds. Door mounted side impact
airbags can provide increased protection to belted
occupants on the impacted side of the vehicle in side
impacts exceeding its preset thresholds.
The operational readiness of the airbag system is
verified by the indicator lamp "SRS" in the instrument
cluster when turning the key in steering lock to
position 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

61 Restraint systems
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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 selfcheck: crash-sensor(s), airbag ignition
circuits, seat belt buckles, emergency tensioning
retractors, seat sensor.
Initially, when the key is turned from steering lock
position 0 to positions 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). In 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 passenger seat belt buckle harnesses, and
low voltage in the entire system are detected and
indicated.Have the system checked at your authorized
Mercedes-Benz Center immediately.
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 unnecessary which could also
result in injury.

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Front airbags
The driver and passenger front airbags are designed to
activate only in certain frontal impacts exceeding a
preset threshold.
The passenger front airbag deploys only if the front
passenger seat is occupied, and the 7 indicator lamp
in the dashboard is not illuminated.
Note:
Heavy objects on the 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.Side impact airbags
The side impact airbags are designed to activate only in
certain side impacts exceeding a preset threshold. Only
the side impact airbag on the impacted side of the
vehicle deploy.
The passenger side impact airbag deploys only if the
passenger seat is occupied.
Side impact airbags operate best in conjunction with a
properly positioned and fastened seat belt.
Note:
Heavy objects on passenger seat can cause the
passenger door side impact airbag to deploy in a crash.
Important!
Airbags are designed to activate only in certain
frontal (front airbags) impacts, or side (side impact
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 must always wear their
seat belts, otherwise it is not possible for the airbags
to provide their intended supplemental protection.

63 Restraint systems
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roll-overs, other side impacts, rear collisions, or
other accidents in which the airbags are not
designed to deploy, the airbags will not be activated.
The driver and passenger 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.
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
protections for occupants.
Wa r n i n g !
Airbags are designed to reduce the potential of
injury in certain frontal (front airbags) impacts,
and side (side impact 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 driverside
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.

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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 their seat belts.
For maximum protection in the event of a collision
always be in normal seated position w ith your back
against the backrest. Fasten your seat belt and
ensure that it is properly positioned on your body.For unobstructive inflation of door side impact
airbags, keep door pocket lids closed.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:• Sit properly belted in an upright position with
your back against the backrest.
• Adjust the driver’s seat as far as possible
rearward, still permitting proper operation of
vehicle controls. Adjust the driver’s 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 the driver front airbag
inflates.• Do not lean against doors.

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• 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. Always sit upright, use the seatbelts,
and appropriate size infant or child restraint
system.• Adjust the passenger seat as far as possible
rearward from the dashboard when the seat is
occupied.
• Children 12 years old and under must never
ride in this vehicle, 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 can result.
Failure to follow these instructions can result in
severe or fatal injuries to you or other occupants.

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Wa r n i n g !Should you choose to place a child 12 years old or
under in the front passenger seat of your vehicle,
you must properly use a BabySmart
TM child
restraint. A BabySmartTM child restraint will turn
off the passenger side front airbag. BabySmart
TM
will not, however, turn off the side impact airbag.It should be noted that there is a possibility for a
side airbag related injury if occupants, especially
children, are not properly seated or restrained
when next to a side airbag which needs to deploy
rapidly in a side impact in order to do its job.
To help avoid the possibility of injury, please follow
these guidelines: (1) occupants, especially
children, should never place their bodies or lean
their heads in the area of the door where the side
airbag inflates. This could result in serious
injuries or death should the side airbag be
activated; (2) always sit upright, properly use the
seat belts and use an appropriately sized infant or
child restraint system for all children 12 years old
or under; and (3) always wear seat belts properly.If you believe that, even with the use of these
guidelines, it would be safer for your front
passenger seat occupant to have the passenger side
door mounted side airbag deactivated, then
deactivation can be accomplished upon your
written election to do so at your authorized
Mercedes-Benz Center at an additional cost. Please
contact your local authorized Mercedes-Benz
Center or call our Client Assistance Center at
1-800-FOR-MERCedes (1-800-367-6372) for details.