MERCEDES-BENZ R320 2008 W251 Manual Online

80 Safety and Security
Occupant safety

If you must install a rear-facing child
restraint on the front passenger seat
because circumstances require you to
do so, make sure that the
59 indicator lamp is illumi-
nated, indicating that the front passen-
ger front air bag is deactivated. Should
the 59 indicator lamp not
illuminate or go out while the restraint is
installed, please check installation. Peri-
odically check the 59 indi-
cator lamp while driving to make sure
the 59 indicator lamp is il-
luminated. If the 59 indica-
tor lamp goes out or remains out, do not
transport a child on the front passenger
seat until the system has been repaired.
A child in a rear-facing child restraint on
the front passenger seat will be seri-
ously injured or even killed if the front
passenger front air bag inflates.
If you have to place a child in a
forward-facing child restraint on the
front passenger seat, move the seat as
far back as possible, use the proper
child restraint recommended for the
age, size and weight of the child, and se-
cure child restraint with the vehicle’s
seat belt according to the child seat
manufacturer’s instructions. For
children larger than the typical
12-month-old child, the front passenger
front air bag may or may not be activat-
ed (
page 77).
iDeployment of the driver front air bag does
not mean that the front passenger front air bag
also should have deployed.
The Occupant Classification System (
page 77)
may have determined:

that the seat was empty or occupied by the
weight up to or less than that of a typical
12-month-old child seated in a standard
child restraint – both instances where the
system suppresses deployment of the front
passenger front air bag even though the im-
pact met the criteria and was of sufficient
severity to deploy the driver front air bag

that the seat was occupied by a small individ-
ual (such as a young teenager or a small
adult) or a child weighing more than the
weight of a typical 12-month-old child in a
standard child restraint – instances where
the system may suppress deployment of the
front passenger front air bag even though
the impact met the criteria and was of suffi-
cient severity to deploy the driver front air
bag


81 Safety and Security
Occupant safety
The 59indicator lamp is lo-
cated in the center console.
159 indicator lamp
The 59indicator lamp1 will
be illuminated, except with the SmartKey
removed from the starter switch or with
the starter switch in position0
(
page 39).
Warning!G
If the 1indicator lamp and the
59indicator 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 possible by qualified technicians.
Contact an authorized Mercedes-Benz Light
Truck Center.
Only have the seat repaired or replaced by
an authorized Mercedes-Benz Light Truck
Center.
In order to ensure proper operation of the
air bag system and OCS:

Do not place more than 4.4 lbs (2 kg)
into the parcel net on the back of the
front passenger seat. Otherwise, the
OCS may not be able to properly approx-
imate the occupant weight category.

Do not place objects under and/or
around the front passenger seat.

Do not hang anything from or attach any
items to the seats.

Do not stuff objects such as books be-
tween the middle console and the front
passenger seat.

Do not move the front passenger seat
backwards against stiff objects.

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 to be unable to correctly
approximate the occupant’s weight
category.

Read and observe all warnings in this
chapter.

82 Safety and Security
Occupant safety
Self-test Occupant Classification Sys-
tem
After turning the SmartKey in the starter
switch to position1or2or pressing the
KEYLESS-GO* start/stop button once or
twice, the59indicator lamp
(
page 81) 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, the59indicator lamp
will illuminate and go out after approxi-
mately 6 seconds.
If the seat is not occupied and the system
senses the front passenger seat as being
empty, the59indicator lamp
will illuminate and not go out.For more information, see the “Practical
hints” section (
page 425).
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 information on fastening seat belts,
see “Fastening the seat belts” (
page 50).
Warning!G
If the 59 indicator lamp should
not illuminate, the system is not functioning.
You must see an authorized Mercedes-Benz
Light Truck 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
Classification 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 protection for the child.
Follow the manufacturer’s instructions for
installation of child seats.
iFor information on infants and children
traveling with you in the vehicle and restraint
systems for infants and children, see “Children
in the vehicle” (
page 87).

83 Safety and Security
Occupant safety
Warning!G
Always fasten your seat belt before driving
off. Always make sure all of your passengers
are properly restrained, even those sitting in
the rear.
Failure to wear and properly fasten and po-
sition 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 prop-
erly wearing their seat belts.
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 ab-
domen 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 cor-
rectly restrained with a separate seat belt.
Never use a seat belt for more than one per-
son at a time.
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 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 failure.
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 Light Truck Center.

84 Safety and Security
Occupant safety
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 sec-
tion, as that could result in serious inju-
ries 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, pas-
senger front air bag, side impact air
bags, window curtain air bags for side
windows) and ETD (seat belt emergency
tensioning device), and front seat knee
bolsters. The system is designed to en-
hance the protection offered to properly
belted occupants in certain frontal (front
air bags and ETD) and side (side impact,
window curtain air bags and ETD) im-
pacts which exceed preset deployment
thresholds and in certain rollovers (win-
dow curtain air bags and ETD).

Never wear the shoulder belt under your
arm, against your neck or off your shoul-
der. In a frontal crash, your body would
move too far forward. That would in-
crease the chance of head and neck in-
juries. The belt would also apply too
much force to the ribs or abdomen,
which could severely injure internal or-
gans such as your liver or spleen.

Never wear belts over rigid or breakable
objects in or on your clothing, such as
eyeglasses, pens, SmartKeys, etc., as
these might cause injuries.

Position the lap belt as low as possible
on your hips and not across the abdo-
men. If the belt is positioned across your
abdomen, it could cause serious injuries
in a crash.

Never use a seat belt for more than one
p e r s o n a t t i m e . D o n o t f a s t e n a s e a t b e l t
around a person and another person or
other objects.

Belts should not be worn twisted. In a
crash, you would not have the full width
of the belt to distribute impact forces.
The twisted belt against your body could
cause injuries.

Pregnant women should also always 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, dashboard or on the seat. Always
keep both feet on the floor in front of the
seat.

When using a seat belt to secure infant
or toddler restraints or children in
booster seats, always follow the child
seat manufacturer’s instructions.

85 Safety and Security
Occupant safety
Enhanced seat belt reminder system
When the engine is started, the seat belt
telltale< will always illuminate
for 6 seconds to remind you and your
passengers to fasten your seat belts.
If the driver’s seat belt is not fastened
when the engine is started, an additional
warning chime will also sound for a maxi-
mum of 6 seconds or until the driver’s seat
belt is fastened.
If after these 6 seconds, the driver’s or the
front passenger’s seat belt (with the front
passenger seat occupied) are not fastened
with all doors closed,

the seat belt telltale< remains illu-
minated for as long as either the
driver’s or front passenger’s seat belt is
not fastened

and if the vehicle speed exceeds
15 mph (25 km/h), the seat belt
telltale< starts flashing and a
warning chime sounds with increasing
intensity for a maximum of 60 seconds
or until the driver’s and the front
passenger’s seat belt are fastened
If the driver’s or the front passenger’s
seat belt remains unfastened after
60 seconds, the warning chime stops
sounding and the seat belt
telltale< stops flashing but
continues to be illuminated.
The seat belt telltale< will only go out
if both the driver’s and the front passen-
ger’s seat belt (with the front passenger
seat occupied) are fastened, or the vehicle
is standing still and a front door is opened.
For more information, see “Practical hints”
(
page 420).Emergency Tensioning Device (ETD),
seat belt force limiter
The seat belts for following seats are
equipped with emergency tensioning de-
vices and seat belt force limiters:

front seats

outboard second-row seats

third-row seats
The ETD is designed to activate in the
following cases:

in frontal or rear-end impacts
exceeding the system deployment
threshold

in certain vehicle rollovers

if the restraint systems are operational
and functioning correctly, see
1indicator lamp (
page 424)
iThe ETDs for the front seats will only acti-
vate if the respective front seat belt is fastened
(latch plate properly inserted into buckle).
The ETDs for the rear seats will activate with or
without the respective seat belt fastened.

86 Safety and Security
Occupant safety
In an impact, emergency tensioning
devices remove slack from the belts in
such a way that the seat belts fit more
snugly against the body. Belt force limiters,
when activated, are employed to help
reduce the peak force exerted by the seat
belts on occupants during a crash.Active head restraints
The active head restraints are intended to
offer the driver and front passenger
increased protection from whiplash type
injuries. In the event of a rear-end collision,
the active head restraints on the driver’s
and front passenger’s seats are designed
to move forward in the direction of travel,
providing the head with increased support
earlier on in the collision sequence. The
active head restraints move forward
whether the seat is occupied or not.
Warning!G
A pyrotechnic Emergency Tensioning Device
(ETD) that was activated must be replaced.
When disposing of the pyrotechnic emer-
gency tensioning device, our safety instruc-
tions must be followed. These are available
at your authorized Mercedes-Benz Light
Truck Center.
Warning!G
Only use seat or head restraint covers which
have been tested and approved by
Mercedes-Benz for your vehicle model.
Using other seat or head restraint covers
may interfere with or prevent the activation
of the active head restraint. Contact an
authorized Mercedes-Benz Light Truck
Center for availability.
Do not attach any objects (e.g. hangers) to
the head restraints posts. Otherwise, the
active head restraints may not be able to
function properly or offer the intended
degree of protection in the event of an
accident.
Warning!G
For your protection, drive only with properly
positioned head restraints.
Adjust head restraint so that it is as close to
the head as possible and the center of the
head restraint supports the back of the head
at eye level. This will reduce the potential for
injury to the head and neck in the event of
an accident or similar situation.

87 Safety and Security
Occupant safety
You cannot remove the active head
restraint on the driver’s and front passen-
ger’s seats.
For removal of the active head restraints
we recommend that you contact an
authorized Mercedes-Benz Light Truck
Center.
For information on head restraint adjust-
ment, see “Seats” (
page 43).
For information on resetting the activated
active head restraints, see “Resetting acti-
vated head restraints” (
page 477).
Rear head restraintsChildren in the vehicle
If an infant or child is traveling with you in
the vehicle:

Secure the child using an infant or child
restraint appropriate to the age and
size of the child.

Make sure the infant or child is
properly secured at all times while
the vehicle is in motion.
Warning!G
Do not drive the vehicle without the seat
head restraints installed when the rear seats
are occupied. Head restraints are intended
to help reduce injuries during an accident.
With the second-row middle seat* or a
third-row seat occupied, make sure to move
the respective head restraint up from the
lowest non-use position and have the occu-
pant adjust the head restraint properly.
For your protection, drive only with properly
positioned head restraints.
Adjust the head restraint in such a way that
it is as close to the head as possible and the
head restraint supports the back of the head
at eye level. This will reduce the potential for
injury to the head and neck in the event of
an accident or similar situation.
Warning!G
Do not leave children unattended in the
vehicle, even if they are secured in a child
restraint system. The children could

injure themselves on parts of the vehicle

be seriously or fatally injured through
excessive exposure to extreme heat or
cold


88 Safety and Security
Occupant safety
Infant and child restraint systems
We recommend all infants and children be
properly restrained at all times while the
vehicle is in motion.
All lap-shoulder belts except the driver’s
seat belt have special seat belt retractors
for secure fastening of child restraints.
To fasten a child restraint, follow child
restraint instructions for mounting. Then
pull the shoulder belt out completely and
let it retract. During seat belt retraction, a
ratcheting sound can be heard to indicate
that the special seat belt retractor is acti-
vated. The belt is now locked. Push down
on child restraint to take up any slack.
To deactivate, release seat belt buckle and
let seat belt retract completely. To deacti-
vate the special seat belt retractor for the
front passenger seat, the front passenger
seat must be in the most backward posi-
tion. The seat belt can again be used in the
usual manner.The use of infant or child restraints is re-
quired by law in all 50 states, the District
of Columbia, the U.S. territories and all
Canadian provinces.Do not expose the child restraint system to
direct sunlight. The child restraint system’s
metal parts, for example, could become very
hot, and the child could be burned on these
parts.
If children open a door, they could

injure other persons

get out of the car and injure themselves
or be injured by following traffic
Do not carry heavy or hard objects in the
passenger or cargo compartment unless
they are firmly secured in place. For more in-
formation, please refer to the “Loading”
(
page 288) and “Useful features”
(
page 304) sections in the “Controls in
detail” chapter.
Unsecured or improperly positioned cargo
increases a child’s risk of injury in the
event of:

strong braking maneuvers

sudden changes of direction

an accident
Warning!G
Never release the seat belt buckle while the
vehicle is in motion, since the special seat
belt retractor will be deactivated.
iFor information on child seats with mounting
fittings for tether anchorages, see “Installation
of infant and child restraint system”
(
page 92).
For information on LATCH type child seat
mounts, see “Child seat anchors – LATCH type”
(
page 91).


89 Safety and Security
Occupant safety
Infants and small children should be
seated in an appropriate infant or child
restraint system properly secured in
accordance with the manufacturer’s
instructions for the child restraint, that
complies with U.S. Federal Motor Vehicle
Safety Standards 213 and 225 and
Canadian Motor Vehicle Safety
Standards 213 and 210.2.
A statement by the child restraint manu-
facturer of compliance with these stan-
dards can be found on the instruction label
on the restraint and in the instruction man-
ual provided with the restraint.
When using any infant or child restraint
system, make sure to carefully read and
follow all manufacturer’s instructions for
installation and use.
Please read and observe warning labels
affixed to inside of vehicle and to infant or
child restraints.
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, or lower anchors
and top tether strap, fully in accordance
with the child seat manufacturer’s instruc-
tions.
Always sit as upright as possible, properly
use the seat belts and use an appropriately
sized infant restraint, toddler restraint, or
booster seat recommended for the size and
weight of the child.
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 OCS 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 serious-
ly injured or even killed if the front pas-
senger front air bag inflates in a collision
which could occur under some circum-
stances, even with the air bag tech-
nology 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.