MERCEDES-BENZ C-Class SEDAN 2014 W204 Workshop Manual

Ac
hild 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.
R If you 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
- secure child restraint with the vehicle's
seat belt according to the child seat
manufacturer's instructions
R For children larger than the typical 12-
month-old child, the front-passenger front
air bag may or may not be activated.
If the driver's air bag deploys, this does not
mean that the front-passenger front air bag
will also deploy.
The OCS may have detected that the seat:
R is empty or occupied by the weight of a
typical child up to twelve months old,
seated in a child restraint system.
R is occupied by a small individual, such as a
young teenager or a small adult.
R is occupied by a child in a child restraint
system whose weight is greater than that
of a typical twelve month old child.
These are examples of when the OCS
deactivates the front-passenger front air bag.
Deactivation takes place although the
collision fulfills the criteria for deploying the
driver's air bag. If the SmartKey is removed from the ignition
lock or is in position
0, the PASSENGER AIR
BAG OFF indicator lamp does not light up. G
WARNING
If the red 001ESRS warning lamp in the
instrument cluster and the 0019001B
indicator lamp light up simultaneously, the
OCS is malfunctioning. The front passenger
front air bag will be deactivated in this case.
Have the system checked by qualified
technicians as soon as possible. Contact an
authorized Mercedes-Ben zCenter.
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:
R Sit with the seat belt properly fastened in a
position that is as upright as possible with
your back against the seat backrest.
R When seated, a passenger should not
position him/herself in such a way as to
cause the passenger's weight to be lifted
from the seat cushion as this may result in
the OCS being unable to correctly
approximate the passenger's weight
category.
R Read and observe all warnings in this
chapter.
System self-test The PASSENGER AIR BAG OFF indicator lamp
lights up if you:
R
turn the SmartKey to position 1or 2in the
ignition lock
R press the KEYLESS-GO Start/Stop button
once or twice on vehicles with KEYLESS-
GO.
When an adult is sitting correctly on the front-
passenger seat and is categorized by the OCS
system as an adult, the PASSENGER AIR BAG
OFF indicator lamp lights up and goes off
again after approximately six seconds.
If the seat is not occupied and the OCS
system classifies the front-passenger seat as Occupant safety
49Safety Z

being empty, the PASSENGER AIR BAG OFF
indicator lamp will continue to light up and
not go out. G
WARNING
If the 0019001Bindicator lamp does not
illuminate, the system is not functioning. You
must contact an authorized Mercedes-Benz
Center before seating any child on the front
passenger seat.
For more information about the OCS, see
"Problems with the Occupant Classification
System" (Y page 51). G
WARNING
Objects betwee nthe seat surface and the
child restraint system could affect the
function of the OCS. This could result in the
front-passenger front air bag not functioning
as intended during an accident. This poses an
increased risk of injury or even fatal injury.
Do not place any objectsb etween the seat
surface and the child restraint system. Make
sure that the bottom and back of the child
restraint system make full contact with the
front-passenger seat cushion and backrest.
Always comply with the child restraint system
manufacturer's installation instructions. 50
Occupant safetySafety

Problems with the Occupant Classification System
Problem Possible causes/consequences and
0001 Solutions
The PASSENGER AIR
BAG OFF indicator
lights up and remains
on.
The person on the
front-passenger seat:
R
has the weight of a
typical adult
R has been determined
by the system not to
be a child The OCS is malfunctioning.
X
Make sure that the front passenger is sitting in a correct, upright
position.
X Have the OCS checked as soon as possible at a qualified
specialist workshop.
X Observe the additional display messages in the multifunction
display (Y page 229). G
WARNING
If the 0019001B indicator lamp illuminates and remains illuminated when the weight of a typical
adult or someone larger than a small individual has been detected on the passenger seat, do not
allow any occupant to use the passenger seat until the system has been repaired. Problem Possible causes/consequences and
0001 Solutions
The PASSENGER AIR
BAG OFF indicator
lamp does not light up
and/or stays on.
The front-passenger
seat is:
R
unoccupied
R occupied with a
weight up to that of a
typical twelve-
month-old child in a
standard child
restraint system The OCS is malfunctioning.
X
Make sure there is nothing between the seat cushion and the
child seat.
X Make sure that the backrest and base of the child restraint
system are resting securely on the front-passenger seat. If
necessary, adjust the position of the front-passenger seat.
X When installing the child restraint system, make sure that the
seat belt is tight. Do not pull the seat belt tight with the front-
passenger seat adjustment .This could result in the seat belt
being pulled too tightly.
X Check the installation of the child restraint system.
X Make sure that no objectsa re applying additional weight onto
the seat.
X If the PASSENGER AIR BAG OFF indicator lamp remains off, have
the OCS system checked as soon as possible at a qualified
specialist workshop. Do not transport a child on the front-
passenger seat until the OCS has been repaired.
X Observe the additional display messages in the multifunction
display (Y page 229). Occupant safety
51Safety Z

G
WARNING
If the 0019001B indicator lamp does not illuminate or remains out with the weight of a typical
12-month-old child in a standard child restraint or less, or is unoccupied, on the front-passenger
seat, do not transport achild on the front-passenger seat until the system has been repaired. PRE-SAFE
®
(anticipatory occupant
protection system) G
WARNING
The PRE-SAFE ®
system reduces the impact of
an accident on vehicle occupants, as long as
their seat belts have been fastened correctly.
Although your vehicle is equipped with a PRE-
SAFE ®
system, the possibility of injury in the
event of an accident cannot be ruled out. You
should therefore always drive carefully and
adapt your driving style to the prevailing road,
weather and traffic conditions.
PRE-SAFE ®
takes preemptive measures to
protect occupants in certain hazardous
situations.
PRE-SAFE ®
intervenes:
R if BAS PLUS intervenes powerfully on
vehicles with DISTRONIC PLUS
R if, on vehicles with DISTRONIC PLUS, the
radar sensor system detects an imminent
danger of collision in certain situations
R in critical driving situations, e.g. when
physical limits are exceeded and the
vehicle understeers or oversteers severely
PRE-SAFE ®
takes the following measures
depending on the hazardous situation
detected:
R the front seat belts are pre-tensioned.
R on vehicles with memory function for the
front-passenger seat: the front-passenger
seat is adjusted if it is in an unfavorable
position.
R if the vehicle skids, the sliding sunroof,
panorama roof with power tilt/sliding
panel and the side windows are closed so
that only a small gap remains. If the hazardous situation passes without
resulting in an accident, PRE-SAFE ®
slackens
the belt pre-tensioning. All settings made by
PRE-SAFE ®
can then be reversed.
If the seat belts are not released:
X When the vehicle is stationary, move the
backrest or seat back slightly.
The seat belt pre-tensioning is reduced and
the locking mechanism is released. G
WARNING
Make sure that nobody can become trapped
as you adjust the seat.
! Make sure that there are no objects in the
footwell or behind the seats when resetting
the seats. There is a risk that the seats
and/or the objects could be damaged.
More information about seat belt adjustment,
a convenience function integrated into PRE-
SAFE ®
, can be found in the "Seat belt
adjustment" section (Y page 56). NECK-PRO head restraints/NECK-
PRO luxury head restraints (except
AMG vehicles)
G
WARNING
The function of the head restraint may be
impaired if you:
R attach objects such as coat hangers to the
head restraints, for example
R use head restraint covers
If you do so, the head restraints cannot fulfill
their intended protective function in the event
of an accident. In addition, objects attached
to the head restraints could endanger other 52
Occupant safetySafety

vehicle occupants. There is an increased risk
of injury.
Do not attach any objects to the head
restraints and do not use head restraint
covers.
NECK-PRO head restraints/NECK-PRO luxury
head restraints increase protection of the
driver's and front-passenger's head and
neck. In the event of a rear collision of a
certain severity, the NECK-PRO head
restraints/NECK-PRO luxury head restraints
on the driver's and the front-passenge rseats
are moved forwards and upwards. This
provides better head support.
If the NECK-PRO head restraints/NECK-PRO
luxury head restraints have been triggered in
an accident, reset the NECK-PRO head
restraints/NECK-PRO luxury head restraints
on the driver's and front-passenger seats
(Y page 53). Otherwise, the additional
protection will not be available in the event of
another rear-end collision. NECK-PRO head
restraints/NECK-PRO luxury head restraints
that have been triggered are moved forwards
and can no longer be adjusted.
Mercedes-Benzr ecommends that you have
the NECK-PRO head restraints/NECK-PRO
luxury head restraints checked at a qualified
specialist workshop after a rear-end collision. Resetting triggered NECK-PRO head
restraints/NECK-PRO luxury head
restraints
Important safety notes G
WARNING
For reasons of safety, have the NECK-PRO
head restraints/NECK-PRO luxury head
restraints checked at an authorized
Mercedes-Benz Center after a rear-end
collision. G
WARNING
When pushing back the NECK-PRO head
restraint cushion, make sure your fingers do
not become caught between the head
restraint cushion and the cover. Failure to
observe this could result in injuries.
NECK-PRO head restraints i
Resetting the NECK-PRO head restraints
requires a lot of strength. If you have
difficulty resetting the NECK-PRO head
restraints, have this work carried out at a
qualified specialist workshop, e.g. an
authorized Mercedes-BenzC enter. X
Tilt the top of the NECK-PRO head restraint
cushion forwards in the direction of
arrow 0002.
X Push the NECK-PRO head restraint cushion
down in the direction of arrow 0003as far as
it will go.
X Firmly push the NECK-PRO head restraint
cushion back in the direction of arrow 0022
until the cushion engages.
X Repeat this procedure for the second
NECK-PRO head restraint.
NECK-PRO luxury head restraints i
If you have difficulty resetting the NECK-
PRO luxury head restraints, have this work
carried out at a qualified specialist
workshop, e.g. an authorized Mercedes-
Benz Center. Occupant safety
53Safety Z

X
Remove resetting tool 0002from the vehicle
documen twallet.
X Slide resetting tool 0002into guide 0003
between the NECK-PRO luxury head
restraint and the rear cover of the head
restraint.
X Push resetting tool 0002downwards until you
hear the head restraint deployment
mechanism engage.
X Pull out resetting tool 0002.
X Firmly press the NECK-PRO luxury head
restraint cushion back 0022until it engages.
X Repeat this procedure for the second
NECK-PRO luxury head restraint.
X Put resetting tool 0002back into the vehicle
documen twallet. Seat belts
Important safety notes The use of seat belts and infant and child
restraint systems is required by law in:
R
all 50 states
R the U.S. territories
R the District of Columbia
R all Canadian provinces
Even where this is no tthe case, all vehicle
occupants should have their seat belts
fastened when the vehicle is in motion.
i See "Children in the vehicle"
(Y page 59) for further information on infants and children traveling in the vehicle
as well as on child restraint systems. G
WARNING
The seat belt does not offer the intended level
of protection if the backrest is not in the
upright position. When braking or in the event
of an accident, you could slide underneath the
seat belt and sustain abdomen or neck
injuries, for example. This poses an increased
risk of injury or even fatal injury.
Adjust the seat properly before beginning
your journey. Always make sure that the seat
is in the upright position. G
WARNING
Seat belts cannot protect as intended, if:
R they are damaged, extremely dirty,
bleached or dyed
R the seat belt buckle is damaged or
extremely dirty
R the Emergency Tensioning Devices or the
belt anchorage has been modified.
Damage caused to seat belts in an accident
may not be visible, e.g. by splinters of glass.
Modified or damaged seat belts can tear or
fail, for example in the event of an accident.
Modified Emergency Tensioning Devices may
be deployed unintentionally or fail to be
deployed when required. There is an
increased risk of injury, possibly even fatal.
Never modify seat belts, Emergency
Tensioning Devices, seat belt anchorages and
inertia reels. Ensure that seat belts are not
damaged or worn and are clean.
Only use seat belts that have been approved
for your vehicle by Mercedes-Benz.
The use of seat belts and infant and child
restraint systems is required by law in:
R all 50 states
R the U.S. territories
R the DistrictofC olumbia
R all Canadia nprovinces 54
Occupant safetySafety

Even where this is not required by law, all
vehicle occupants should correctly fasten
their seat belts before starting the journey.
i See "Children in the vehicle"
(Y page 59) for further information on
infants and children traveling in the vehicle
as well as on child restraint systems.
Correct use of the seat belts G
WARNING
USE SEAT BELTS PROPERLY
R Sea tbelts 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 the
event of an accident.
R 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, including rollovers.
The integrated restraint system includes
SRS (driver fron tair bag, driver's side knee
bag, front-passenge rfront air bag, side
impact air bags, pelvis air bags, window
curtain air bags for the side windows),
Emergency Tensioning Devices, seat belt
force limiters, and front seat knee bolsters.
The system is designed to enhance the
protection offered to properly belted
occupants in certain frontal (front air bags,
driver's side knee bag, and ETDs) and side
(side impact air bags, pelvi sair bags,
window curtain air bags, and ETDs) impacts
which exceed prese tdeployment
thresholds.
R Never wear the shoulder belt under your
arm, across your neck or off your shoulder.
In a frontal crash, your body would move
too far forward. That would increase the
chance of head and neck injuries. The seat
belt would also apply too much force to the
ribs or abdomen, which could severely
injure internal organs such as your liver or
spleen. Adjust the seat belt so that the shoulder
section is located as close as possible to
the middle of the shoulder. It should not
touch the neck .Never pass the shoulder
portion of the seat belt under your arm.
R Position the lap belt as low as possible on
your hips and not across the abdomen. If
the lap belt is positioned across your
abdomen, it could cause serious injuries in
a crash.
R Never wear seat belts over rigid or
breakable objects in or on your clothing,
such as eyeglasses, pens, keys etc., as
these might cause injuries.
R Make sure the seat belt is always fitted
snugly. Take special care of this when
wearing loose clothing.
R Never use a seat belt for more than one
person at a time. Do not fasten a seat belt
around a person and another person or
other objects at the same time.
R Seat belts should not be worn twisted. In a
crash, you would not have the full width of
the seat belt to distribut eimpact forces.
The twisted seat belt against yourb ody
could cause injuries.
R 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.
R Place the seat backrest in a position that is
as upright as possible.
R Check your seat belt during travel to make
sure it is properly positioned.
R 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.
R When using a seat belt to secure infant
restraints, toddler restraints, or children in
booster seats, always follow the child seat
manufacturer's instructions. Occupant safety
55Safety Z

G
WARNING
Do not pass seat belts over sharp edges. They
could tear.
Do not allow the seat beltt o get caught in the
door or in the seat adjustment mechanism.
This could damage the seat belt.
Never attempt to make modifications to seat
belts. This could impair the effectiveness of
the seat belts.
Fastening seat belts G
WARNING
According to accident statistics, children are
safer when properly restrained on the rear
seats than on the front-passenger seat. Thus,
we strongly recommend that children be
placed in the rear seat whenever possible.
Regardless of seating position, children 12
years old and under must be seated and
properly secured in an appropriately sized
child restraint system or booster seat
recommended for the size and weight of the
child. For additional information, see the
"Children in the vehicle" section.
Ac hild's risk of serious or fatal injuries is
significantly increased if the child restraints
are not properly secured in the vehicle and/
or the child is not properly secured in the child
restraint. X
Adjust the seat and move the backrest to
an almost vertical position (Y page 98).
X Pull the seat belt smoothly through belt
sash guide 0002.
X Without twisting it, guide the shoulder
section of the seat belt across the middle
of your shoulder and the lap section across
your pelvis.
X Engage belt tongue 0003in buckle 0022.
X If necessary, adjust the seat belt to the
appropriate height (Y page 56).
X If necessary, pull upwards on the shoulder
section of the seat belt to tighten the belt
across your body.
All seat belts except the driver's seat belt are
equipped with a special seat belt retractor to
securely fasten child restraint systems in the
vehicle. For further information on special
seat belt retractors, see (Y page 61).
For more information about releasing the seat
belt with release button 0021, see "Releasing
seat belts" (Y page 57).
Seat belt adjustment The seat-belt adjustment function adjusts the
driver's and front-passenger seat belt to the
upper body of the occupants.
The belt strap is tightened slightly when:
R
you engage the belt tongue in the belt
buckle and you then turn the SmartKey to
position 2in the ignition lock.
The seat-belt adjustment is an integral part of
the PRE-SAFE ®
convenience function. More
information about PRE-SAFE ®
can be found
in the "PRE-SAFE ®
(anticipatory occupant
protection system)" section (Y page 52).
Belt height adjustment You can adjust the seat belt height on the
driver's seat and the front-passenger seat. 56
Occupant safetySafety

Adjust the height so tha
tthe upper part of the
seat belt is routed across the center of your
shoulder.
X To raise: slide the belt sash guide upwards.
The belt sash guide engages in various
positions.
X To lower: press and hold belt sash guide
release 0002.
X Slide the belt sash guide downwards.
X Release belt sash guide release 0002and
make sure that the belt sash guide has
engaged.
Releasing seat belts X
Press release button 0021on belt buckle 0022.
X Guide belt tongue 0003to belt sash
guide 0002. !
Make sure that the seat belt is fully rolled
up. Otherwise, the seat belt or belt tongue
will be trapped in the door or in the seat
mechanism. This could damage the door,
the door trim panel and the seat belt.
Damaged seat belts can no longer fulfill
their protective function and must be
replaced. Visit a qualified specialist
workshop.
Belt warning for the driver and front
passenger Regardless of whether the driver's and front-
passenger seat belts have already been
fastened, the
001Fseat belt warning lamp
lights up for six seconds each time the engine
is started. It then goes out if the driver and
the front passenger have already fastened
their seat belts.
If the driver's seat belt is not fastened when
the engine is started, an additional warning
tone will sound. This warning tone stops after
a maximum of six seconds or once the
driver's seat belt is fastened.
If after six seconds the driver or front
passenger have not fastened their seat belts
and the doors are closed, the 001Fseat belt
warning lamp lights up:
R until the driver's or front passenger's seat
belt is fastened
R if a vehicle speed of 15 mph (25 km/h) is
exceeded, a warning tone also sounds with
increasing intensity for a maximum of
60 seconds or until the driver or front-
passenger seat belt has been fastened.
If the driver/front passenger unfasten their
seat belt while the vehicle is in motion, the
001F seat belt warning lamp lights up and a
warning tone sounds again.
The warning tone ceases even if the driver or
front-passenger seat belt has still not been
fastened after 60 seconds. The 001Fseat belt
warning lamp stops flashing but remains
illuminated. Occupant safety
57Safety Z

After the vehicle comes to a standstill, the
warning tone is reactivated and the 001Fseat
belt warning lamp flashes agai nifthe vehicle
speed again exceeds 15 mph (25 km/h).
The 001F seat belt warning lamp only goes
out if:
R both the driver and the front passenger
have fastened their seat belts.
or
R the vehicle is stationary and a door is open.
i For more information on the 001Fseat
belt warning lamp, see "Warning and
indicator lamps in the instrument cluster,
seat belts" (Y page 248).
Emergency Tensioning Devices, seat
belt force limiters G
WARNING
Pyrotechnic Emergency Tensioning Devices
that have been deployed are no longer
operational and are unable to perform their
intended protective function. This poses an
increased risk of injury or even fatal injury.
Therefore, have pyrotechnic Emergency
Tensioning Devices which have been
triggered immediately replaced at a qualified
specialist workshop.
! If the front-passenger seat is not
occupied, do not engage the seat belt
tongue in the buckle on the front-
passenger seat. Otherwise, the Emergency
Tensioning Device could be triggered in the
event of an accident.
i Vehicles with PRE-SAFE ®
: Emergency
Tensioning Devices that are triggered by an
electric motor can be deployed as often as
desired and do not need to be replaced.
The seat belts for the front seats and rear
outer seats are equipped with ETDs and seat
belt force limiters.
The ETDs tighten the seat belts in an accident,
pulling them close against the body. The ETDs do not correct incorrect seat
positions or incorrectly fastened seat belts.
The ETDs do not pull vehicle occupants back
towards the backrest.
The ETDs can only be activated when:
R
the ignition is switched on
R the restraint systems are operational; see
"SRS warning lamp "( Ypage 41)
R the belt tongue is engaged in the buckle on
each of the lap-shoulder belts in the front
R the front-passenger seat is occupied and
the belt tongue is engaged in the buckle on
the front-passenger side
The ETDs on the outside seats in the rear
compartmenta re triggered independently of
the lock status of the seat belts.
The Emergency Tensioning Devices are
triggered depending on the type and severity
of an accident, if:
R in the event of a head-on or rear-end
collision, the vehicle decelerates or
accelerates rapidly in a longitudinal
direction during the initia lstages of the
impact
R in the event of a side impact, the vehicle
decelerates or accelerates rapidly in a
lateral directio nonthe side opposite the
impact
If the ETDs are deployed, you will hear a bang,
and a small amount of powder may also be
released. Only in rare cases will the bang
affect your hearing. The powder that is
released generally does not constitute a
health hazard and does not indicate that there
is 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.
You can also open the window to allow fresh
air to enter the vehicle interior. The 001ESRS
warning lamp lights up.
If the seat belt is also equipped with a seat
belt force limiter and this is triggered, the 58
Occupant safetySafety