68 Safety and Security
Occupant safety
Safety guidelines for the seat belt,
emergency tensioning device and
air bagiAir bags are designed to deploy only in cer-
tain frontal impacts (front air bags) and in side
impacts (CLK coupe: front side impact air bags,
rear side impact air bags*, and window curtain
air bags. CLK cabriolet: head-thorax air bags and
rear side impact air bags*) which exceed preset
thresholds. Only during these events will they
provide their supplemental protection.
The driver and passenger should always wear
their seat belts. Otherwise it is not possible for
the air bags to provide their supplemental
protection.
In case of other types of impacts and impacts be-
low air bag deployment thresholds, air bags will
not deploy. The driver and passenger will then be
protected to the extent possible by a properly
fastened seat belt. A properly fastened seat belt
is also needed to provide the best possible
protection in a rollover.
We caution you not to rely on the presence of the
air bags in order to avoid wearing your seat belt.
It is important to your safety and that of your pas-
sengers that you replace deployed air bags and
repair any malfunctioning air bags to make sure
the vehicle will continue to provide supplemental
crash protection for occupants.
Warning!G
Damaged seat belts or belts that were
highly stressed in an accident must be
replaced and their anchoring points
must also be checked. Only use belts in-
stalled or supplied at an authorized
Mercedes-Benz Center.
Air bags and Emergency Tensioning
Devices (ETDs) contain Perchlorate
material, which may require special han-
dling and regard for the environment.
Check with your local government’s dis-
posal guidelines. California residents,
see http://www.dtsc.ca.gov/Hazard-
ousWaste/Perchlorate/index.cfm.
Air bags and emergency tensioning de-
vices (ETDs) are designed to function on
a one-time-only basis. An air bag or ETD
that is deployed must be replaced.
Do not pass belts over sharp edges.
They could tear.
Do not make any modification that could
change the effectiveness of the belts.
Do not bleach or dye seat belts as this
may severely weaken them. In a crash
they may not be able to provide ade-
quate protection.
No modifications of any kind may be
made to any components or wiring of
the SRS. This includes changing or
removing any component or part of the
SRS, the installation of additional trim
material, badges, seat covers
(CLK cabriolet) etc. over the steering
wheel hub, front passenger front air bag
cover, outboard sides of the front seat
backrest (CLK cabriolet), door trim pan-
els (CLK coupe), door frame trims (CLK
coupe), or rear side trim panels, and in-
stallation of additional electrical/elec-
tronic equipment on or near SRS
components and wiring. Keep area be-
tween air bags and occupants free from
objects (e.g. packages, purses, umbrel-
las, etc.).
69 Safety and Security
Occupant safety
When you sell your vehicle, we strongly
urge you to give notice to the subsequent
owner that it is equipped with an SRS by
alerting them to the applicable section in
the Operator’s Manual.
CLK coupe: Do not hang items such as
coat hangers from the coat hooks or
handles over the door. These items may
turn into projectiles and cause head and
other injuries when the window curtain
air bag is deployed.
Air bag system components will be hot
after an air bag has inflated. Do not
touch.
Never place your feet on the instrument
panel, dashboard, or on the seat. Always
keep both feet on the floor in front of the
seat.
In addition, improper repair work on the
SRS creates a risk of rendering the SRS
inoperative or causing unintended air
bag deployment. Work on the SRS must
therefore only be performed by qualified
technicians. Contact an authorized
Mercedes-Benz Center.
For your protection and the protection
of others, when scrapping the air bag
unit or emergency tensioning device,
our safety instructions must be fol-
lowed. These instructions are available
from any authorized Mercedes-Benz
Center.
Given the considerable deployment
speed, required inflation volume, and
the textile structure of the air bags,
there is the possibility of abrasions or
other, potentially more serious injuries
resulting from air bag deployment.
Warning!G
CLK cabriolet: Only use seat covers which
have been tested and approved by
Mercedes-Benz for your vehicle model. Us-
ing other seat covers may interfere with or
prevent the deployment of the head-thorax
air bags. Contact your authorized
Mercedes-Benz Center for availability.
71 Safety and Security
Occupant safety
The front side impact air bags, the rear
side impact air bags*, and the window
curtain air bags are deployed:
on the impacted side of the vehicle
in side impacts exceeding a preset de-
ployment threshold
independently of the front air bags
The front side impact air bags, the rear
side impact air bags*, and the window cur-
tain air bags are not deployed in impacts
which do not exceed the system’s deploy-
ment threshold.CLK cabriolet: Head-thorax air bags
1Head-thorax air bag
The head-thorax air bags1 in the drivers
and front passenger seat are deployed:
on the impacted side of the vehicle
in side impacts exceeding a preset de-
ployment threshold
independently of the front air bagsThe head-thorax air bags1 are not de-
ployed in impacts which do not exceed the
system’s deployment threshold.
Warning!G
Only use seat covers which have been
tested and approved by Mercedes-Benz for
your vehicle model. Using other seat covers
may interfere with or prevent the
deployment of the head-thorax air bags.
Contact your authorized Mercedes-Benz
Center for availability.
73 Safety and Security
Occupant safety
Warning!G
If the 56 indicator lamp illuminates
when an adult or someone larger than a
small individual is in the front passenger
seat, have the front passenger re-position
himself or herself in the seat until the
56 indicator lamp goes out.
More information about air bag display
messages (
page 396).
In the event of a collision, the air bag control
unit will not allow front passenger front air
bag deployment when the OCS classified
the front passenger seat occupant as being
up to or less than the weight of a typical
12-month-old child in a standard child
restraint or if the front passenger seat is
sensed as being empty.
When the OCS senses that the front passen-
ger seat occupant is classified as being up
to or less than the weight of a typical
12-month-old child in a standard child
restraint, the 56 indicator lamp will
illuminate when the engine is started and
remain illuminated, indicating that the front
passenger front air bag is deactivated.
When the OCS senses that the front passen-
ger seat is classified as being empty, the
56 indicator lamp will illuminate
when the engine is started and remain
illuminated, indicating that the front
passenger front air bag is deactivated.
When the OCS senses that the front passen-
ger seat occupant is classified as being
heavier than the weight of a typical
12-month-old child seated in a standard
child restraint or as being a small individual
(such as a young teenager or a small adult),the 56 indicator lamp will illuminate
for approximately 6 seconds when the
engine is started and then, depending on
occupant weight sensor readings from the
seat, remain illuminated or go out. With the
56 indicator lamp illuminated, the
front passenger front air bag is deactivated.
With the 56 indicator lamp out, the
front passenger front air bag is activated.
When the OCS senses that the front passen-
ger seat occupant is classified as an adult or
someone larger than a small individual, the
56 indicator lamp will illuminate for
approximately 6 seconds when the engine is
started and then go out, indicating that the
front passenger front air bag is activated.
If the 56 indicator lamp is
illuminated, the front passenger front air
bag is deactivated and will not be deployed.
74 Safety and Security
Occupant safety
If the 56 indicator lamp is not
illuminated, the front passenger front air
bag is activated and will be deployed:
in the event of certain frontal impacts
if impact exceeds a preset deployment
threshold
independently of the front side impact
air bags (CLK coupe), head-thorax air
bag (CLK cabriolet) and/or rear side im-
pact air bags*.
If the front passenger front air bag is
deployed, the rate of inflation will be
influenced by:
the rate of vehicle deceleration as as-
sessed by the air bag control unit
front passenger’s weight category as
identified by the Occupant Classification
System (OCS).
Warning!G
According to accident statistics, children
are safer when properly restrained in the
rear seating positions than in the front seat-
ing position. Thus, we strongly recommend
that children be placed in the rear seats
whenever possible. Regardless of seating
position, children 12 years old and under
must be seated and properly secured in an
appropriate infant or child restraint recom-
mended for the size and weight of the child.
The infant or child restraint must be properly
secured with the vehicle’s seat belt, the seat
belt and top tether strap (CLK coupe), or
lower anchors and top tether strap (CLK
coupe), or seat belt and lower anchors (CLK
cabriolet), fully in accordance with the child
seat manufacturer’s instructions.
Children can be killed or seriously injured by
an inflating air bag. Note the following
important information when circumstances
require you to place a child in the front
passenger seat:
Your vehicle is equipped with air bag
technology designed to turn off the front
passenger front air bag in your vehicle
when the system senses the weight of a
typical 12-month-old child or less along
with the weight of a standard appropri-
ate child restraint on the front passen-
ger seat.
A child in a rear-facing child restraint on
the front passenger seat will be
seriously injured or even killed if the
front passenger front air bag inflates in
a collision which could occur under
some circumstances, even with the air
bag technology installed in your vehicle.
The only means to completely eliminate
this risk is to never place a child in a
rear-facing child restraint in the front
seat. We therefore strongly recommend
that you always place a child in a
rear-facing child restraint in the back
seat.
76 Safety and Security
Occupant safety
The 56indicator lamp is located in
the center console.
1Front passenger front air bag off
indicator lamp
The 56indicator lamp1 will be
illuminated, except with the SmartKey
removed from the starter switch or with
the starter switch in position0.Self-test Occupant Classification
System
After turning the SmartKey in the starter
switch to position1 or2 or pressing the
KEYLESS-GO* start/stop button once or
twice, the 56indicator lamp
located in the center console illuminates. If
an adult occupant is properly sitting on the
front passenger seat and the system
senses the occupant as being an adult,
the56 indicator lamp will
illuminate and go out after
approximately 6 seconds.
If the seat is not occupied and the system
senses the front passenger seat as being
empty, the 56 indicator lamp will
illuminate and not go out.
Warning!G
If the 1indicator lamp and the
56indicator lamp are lit at the same
time, there is a malfunction in the Occupant
Classification System. The front passenger
front air bag will be deactivated in this case.
Have the system checked as soon as possi-
ble by qualified technicians. Contact an au-
thorized Mercedes-Benz Center.
Only have the seat repaired or replaced at
an authorized Mercedes-Benz Center.
In order to ensure proper operation of the
air bag system and OCS:
Sit properly belted in a position that is
as upright as possible with your back
against the seat backrest.
While seated, an occupant should not
position him/herself in such a way as to
cause the occupant’s weight to be lifted
from the seat bottom as this may result
in the OCS being unable to correctly ap-
proximate the occupant’s weight
category.
Read and observe all warnings in this
chapter.
77 Safety and Security
Occupant safety
More information can be found in the
“Practical hints” section (
page 390).
Seat belts
The use of seat belts and infant and child
restraint systems is required by law in all
50 states, the District of Columbia, the
U.S. territories and all Canadian provinces.
Even where this is not the case, all vehicle
occupants should have their seat belts
fastened whenever the vehicle is in
motion.
For more information, see “Fastening the
seat belts” (
page 48).
Warning!G
If the 56 indicator lamp should not
illuminate, the system is not functioning.
You must see an authorized Mercedes-Benz
Center before seating any child on the front
passenger seat.
Warning!G
Never place anything between seat cushion
and child seat (e.g. pillow), since it reduces
the effectiveness of the Occupant Classifi-
cation System. The bottom of the child seat
must make full contact with the passenger
seat cushion. An incorrectly mounted child
seat could cause injuries to the child in case
of an accident, instead of increasing protec-
tion for the child.
Follow the manufacturer’s instructions for
installation of child seats.
iFor information on infants and children trav-
eling with you in the vehicle and restraint sys-
tems for infants and children, see “Children in
the vehicle” (
page 83).
Warning!G
Always fasten your seat belt before driving
off. Always make sure all of your passengers
are properly restrained, including those sit-
ting in the rear.
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 properly wearing
your seat belt. Air bags can only protect as
they are designed if the occupants are
properly wearing their seat belts.
78 Safety and Security
Occupant safety
Warning!G
Never ride in a moving vehicle with the seat
backrest in an excessively reclined position
as this 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 seat backrest and
seat belt provide the best restraint when the
wearer is in a position that is as upright as
possible and the belt is properly positioned
on the body.
Warning!G
Never let more people ride in the vehicle
than there are seat belts available. Make
sure everyone riding in the vehicle is
correctly restrained with a separate seat
belt. Never use a seat belt for more than one
person at a time.
Warning!G
Damaged seat belts or seat belts that were
highly stressed in an accident must be re-
placed and their anchoring points must also
be checked.
Only use seat belts which have been
approved by Mercedes-Benz.
Do not make any modifications to the seat
belts. This can lead to unintended activation
of the ETDs or to their failure to activate
when necessary.
Do not bleach or dye seat belts as this may
severely weaken them. In a crash they may
not be able to provide adequate protection.
Have all work carried out only by qualified
technicians. Contact an authorized
Mercedes-Benz Center.
Warning!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.
Each occupant should wear their seat
belt at all times, because seat belts help
reduce the likelihood of and potential
severity of injuries in accidents, includ-
ing rollovers. The integrated restraint
system includes SRS (driver air bag,
passenger front air bag, CLK coupe:
front side impact air bags, rear side im-
pact air bags*, and window curtain air
bags, CLK cabriolet: head-thorax air
bags and rear side impact air bags*),
ETD (seat belt emergency tensioning de-
vice), and front seat knee bolsters. The
system is designed to enhance the pro-
tection offered to properly belted occu-
pants in certain frontal (front air bags
and ETD)