2018 MERCEDES-BENZ C CLASS Owners Manual

If a child younger than twelve years old and
under 5 ft (1.50m)in height is traveling in the
vehicle:
Ralways secure the child in a child restraint
system suitable for this Mercedes-Benz vehi-
cle. The child restraint system must be appro-
priate to the age, weight and size of the child
Ralways observe the instructions and safety
notes on "Children in the vehicle"
(
Ypage 60) in addition to the child restraint
system manufacturer's installation and oper-
ating instructions
Ralways observe the instructions and safety
notes on the "Occupant classification system
(OCS)" (
Ypage 52)
GWARNING
The seat belts may not perform their intended protective function if:
Rthey are damaged, modified, extremely
dirty, bleached or dyed
Rthe seat belt buckle is damaged or
extremely dirty
Rthe Emergency Tensioning Devices, belt
anchorages or inertia reels have been modi-
fied.
Seat belts may be damaged in an accident,
although the damage may not be visible, e.g.
due to splinters of glass. Modified or damaged
seat belts may tear or fail, e.g. in an accident.
Modified Emergency Tensioning Devices
could accidentally trigger or fail to deploy
when necessary. This poses an increased risk
of injury or even fatal injury.
Never modify the seat belts, Emergency Ten-
sioning Devices, belt anchorages and inertia
reels. Make sure that the seat belts are
undamaged, not worn out and clean. Follow-
ing an accident, have the seat belts checked
immediately at a qualified specialist work-
shop.
Only use seat belts that have been approved for
your vehicle by Mercedes-Benz.
AMG Performance seat: this seat is designed
for the standard three-point seat belt. If you
install another multi-point seat belt, e.g. sport or
racing seat belts, the restraint system cannot
provide the best level of protection.
GWARNING
If you feed seat belts through the opening in
the seat backrest, the seat backrest may be
damaged or may even break in the event of an accident. This poses an increased risk of
injury or even fatal injury.
Only use the standard three-point seat belt.
Never modify the seat belt system.
Proper use of the seat belts
Observe the safety notes on the seat belt
(Ypage 46).
All vehicle occupants must be wearing the seat
belt correctly before beginning the journey. Also
make sure that all vehicle occupants are always
wearing the seat belt correctly while the vehicle
is in motion.
When fastening the seat belt, always make sure
that:
Rthe seat belt buckle tongue is inserted only
into the belt buckle belonging to that seat
Rthe seat belt is pulled tight across your body
Avoid wearing bulky clothing, e.g. a winter
coat.
Rthe seat belt is not twisted
Only then can the forces which occur be dis-
tributed over the area of the belt.
Rthe shoulder section of the belt is routed
across the center of your shoulder
The shoulder section of the seat belt should
not touch your neck or be routed under your
arm or behind your back. Where possible,
adjust the seat belt to the appropriate height.
Rthe lap belt is taut and passes across your lap as low down as possible
The lap belt must always be routed across
your hip joints and not across your abdomen.
This applies particularly to pregnant women.
If necessary, push the lap belt down to your
hip joint and pull it tight using the shoulder
section of the belt.
Rthe seat belt is not routed across sharp, poin-
ted or fragile objects
If you have such items located on or in your
clothing, e.g. pens, keys or eyeglasses, store
these in a suitable place.
Ronly one person is using a seat belt
Infants and children must never travel sitting
on the lap of a vehicle occupant. In the event
Occupant safety47
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of an accident, they could be crushed
between the vehicle occupant and seat belt.
Robjects are never secured with a seat belt if
the seat belt is also being used by one of the
vehicle's occupants
Also ensure that there are never objects
between a person and the seat, e.g. cushions.
Seat belts are only intended to secure and
restrain vehicle occupants. Always observe the
"Loading guidelines" for securing objects, lug-
gage or loads (
Ypage 280).
Fastening and adjusting the seat belts
Observe the safety notes on the seat belt
(Ypage 46) and the notes on correct use of seat
belts (Ypage 47).
If the center rear seat belt is being used, also
observe the information about the seat belt for
the center rear seat (
Ypage 48).
Basic illustration
XAdjust the seat (Ypage 100).
The seat backrest must be in an almost
upright position.
XPull the seat belt smoothly from the belt outlet
and engage belt tongue ;into belt
buckle :.
The seat belt on the driver’s seat and the
front-passenger seat may be tightened auto-
matically, see "Belt adjustment"
(
Ypage 48).
XIf necessary, pull up on the shoulder section
of the seat belt to tighten the belt across your
body. The shoulder section of the seat belt must
always be routed across the center of the shoul-
der. Adjust the belt outlet if necessary.
XTo raise:
slide the belt outlet up.
The belt outlet will engage in various posi-
tions.
XTo lower: hold belt outlet release =and slide
the belt outlet down.
XLet go of belt outlet release =in the desired
position and make sure that the belt outlet
engages.
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. Further information can be found under
"Special seat belt retractor" (
Ypage 60).
Seat belt for the center rear seat
If the left-hand rear seat backrest is folded down
and back up again, the rear center seat belt may
lock. The seat belt can then not be pulled out.
XTo release the rear center seat belt: pull
the seat belt out approximately 1 in (25 mm)
at the belt outlet on the backrest and then
release it again.
The seat belt is retracted and released.
Releasing seat belts
!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 spe-
cialist workshop.
XPress the release button in the belt buckle,
hold the belt tongue firmly and guide the belt
back.
Seat belt adjustment
The belt adjustment is a convenience function
integrated into PRE-SAFE®. With this function,
the driver's and front-passenger seat belts are
adjusted to the upper body of the vehicle occu-
pant.
The seat belt strap will slightly tighten if:
Rthe belt tongue is inserted into the buckle and
Rthe ignition is switched on
48Occupant safety
Safety

The seat belt adjustment will apply a certain
tightening force if any slack is detected between
the vehicle occupant and the seat belt. Do not
grab hold of the seat belt.
You can switch the seat belt adjustment on and
off using the multimedia system. Information on
switching the seat belt adjustment on and off
can be found in the Digital Operating Instruc-
tions.
Belt warning for the driver and front
passenger
The7 seat belt warning lamp in the instru-
ment cluster is a reminder that all vehicle occu- pants must wear their seat belts. It may light up
continuously or flash. In addition, there may be
a warning tone.
Regardless of whether the driver's seat belt has
already been fastened, the 7seat belt warn-
ing lamp lights up for six seconds each time the engine is started. If the front doors are closed
and the driver's or front-passenger seat belt has
not been fastened, the 7seat belt warning
lamp lights up again after the six seconds. As
soon as the driver's and front-passenger seat
belts are fastened or a front door is opened
again, the 7seat belt warning lamp goes out.
If the driver's seat belt is not fastened after the
engine is started, an additional warning tone will sound. The warning tone switches off after six
seconds or once the driver's seat belt is fas-
tened.
If the vehicle's speed exceeds 15 mph
(25 km/h) once and the driver's and front-
passenger seat belts are not fastened, a warning
tone sounds. A warning tone also sounds with
increasing intensity for 60 seconds or until the
driver or front passenger have fastened their
seat belts.
If the driver or front passenger unfasten their
seat belts during the journey, the seat belt warn-
ing is activated again.
Air bags
Introduction
The installation point of an air bag can be rec-
ognized by the AIRBAG marking.
An air bag complements the correctly fastened
seat belt. It is no substitute for the seat belt. The air bag provides additional protection in appli-
cable accident situations.
Not all air bags are deployed in an accident. The
different air bag systems function independ-
ently from one another (
Ypage 56).
However, no system available today can com-
pletely eliminate injuries and fatalities.
It is also not possible to rule out a risk of injury
caused by an air bag due to the high speed at
which the air bag must be deployed.
Important safety notes
GWARNING
If you do not sit in the correct seat position,
the air bag cannot protect as intended and
could even cause additional injury when
deployed. This poses an increased risk of
injury or even fatal injury.
To avoid hazardous situations, always make
sure that all of the vehicle's occupants:
Rhave fastened their seat belts correctly,
including pregnant women
Rare sitting correctly and maintain the great-
est possible distance to the air bags
Rfollow the following instructions
Always make sure that there are no objects
between the air bag and the vehicle's occu-
pants.
RAdjust the seats properly before beginning
your journey. Always make sure that the seat
is in an almost upright position. The center of
the head restraint must support the head at
about eye level.
RMove the driver's and front-passenger seats
as far back as possible. The driver's seat posi-
tion must allow the vehicle to be driven safely.
ROnly hold the steering wheel on the outside.
This allows the air bag to be fully deployed.
RAlways lean against the backrest while driv-
ing. Do not lean forward or lean against the
door or side window. You may otherwise be in
the deployment area of the air bags.
RAlways keep your feet in the footwell in front
of the seat. Do not put your feet on the dash-
Occupant safety49
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board, for example. Your feet may otherwise
be in the deployment area of the air bag.
RFor this reason, always secure persons less
than 5 ft (1.50 m) tall in suitable restraint sys-
tems. Up to this height, the seat belt cannot
be worn correctly.
If a child is traveling in your vehicle, also
observe the following notes:
RAlways secure children under twelve years of age and less than 5 ft (1.50 m)tall in suitable
child restraint systems.
RChild restraint systems should be installed on
the rear seats.
ROnly secure a child in a rearward-facing child
restraint system on the front-passenger seat
when the front-passenger front air bag is
deactivated. If the PASSENGER AIR BAG OFF
indicator lamp is permanently lit, the front-
passenger front air bag is deactivated
(
Ypage 45).
RAlways observe the instructions and safety
notes on the "Occupant Classification System
(OCS)" (
Ypage 52) and on "Children in the
vehicle" (Ypage 60) in addition to the child
restraint system manufacturer's installation
and operating instructions.
Objects in the vehicle interior may prevent
an air bag from functioning correctly. Before
starting your journey and to avoid risks resulting
from the speed of the air bag as it deploys, make sure that:
Rthere are no people, animals or objects
betwe en the vehicle occupants and an air bag
Rthere are no objects between the seat, door
and B-pillar
Rthere are no hard objects, e.g. coat hangers,
hanging on the grab handles or coat hooks
Rno accessories, such as cup holders, are
attached to the vehicle within the deployment
area of an air bag, e.g. to doors, side windows,
rear side trim or side walls
Rno heavy, sharp-edged or fragile objects are in
the pockets of your clothing. Store such
objects in a suitable place
GWARNING
If you modify the air bag cover or affix objects
such as stickers to it, the air bag can no longer function correctly. There is an increased risk
of injury.
Never modify an air bag cover or affix objects
to it.
GWARNING
Sensors to control the air bags are located in
the doors. Modifications or work not per-
formed correctly to the doors or door panel-
ing, as well as damaged doors, can lead to the
function of the sensors being impaired. The air
bags might therefore not function properly
anymore. Consequently, the air bags cannot
protect vehicle occupants as they are
designed to do. There is an increased risk of
injury.
Never modify the doors or parts of the doors.
Always have work on the doors or door pan-
eling carried out at a qualified specialist work-
shop.
Front air bags
!Do not place heavy objects on the front-
passenger seat. This could cause the system
to identify the seat as being occupied. In the
event of an accident, the restraint systems on
the front-passenger side may be triggered
and have to be replaced.
Driver's air bag :deploys in front of the steer-
ing wheel. Front-passenger front air bag ;
deploys in front of and above the glove box.
When deployed, the front air bags offer addi-
tional head and thorax protection for the occu-
pants in the front seats.
The PASSENGER AIR BAG OFF indicator lamp
informs you about the status of the front-
passenger front air bag (
Ypage 45).
50Occupant safety
Safety

The front-passenger front air bag will only
deploy if:
Rthe system, based on the OCS weight sensor
readings, detects that the front-passenger
seat is occupied (
Ypage 52). The
PASSENGER AIR BAG OFF indicator lamp is
not lit (
Ypage 52)
Rthe restraint system control unit predicts a
high accident severity
Driver's knee bag
Driver's knee bag :deploys under the steering
column. The driver's knee bag is always
deployed along with the driver's front air bag.
The driver's knee bag offers additional thigh,
knee and lower leg protection for the occupant
in the driver's seat.
Side impact air bags
GWARNING
Unsuitable seat covers can obstruct or pre-
vent deployment of the air bags integrated
into the seats. Consequently, the air bags
cannot protect vehicle occupants as they are designed to do. In addition, the operation of
the occupant classification system (OCS)
could be adversely affected. This poses an
increased risk of injury or even fatal injury.
You should only use seat covers that have
been approved for the respective seat by
Mercedes-Benz.
Front side impact air bags :and rear side
impact air bags ;deploy next to the outer bol-
ster of the seat backrest.
When deployed, the side impact air bag offers
additional thorax protection. However, it does
not protect the:
RHead
RNeck
RArms
If the restraint system control unit detects a side
impact, the side impact air bag is deployed on
the side on which the impact occurs.
The side impact air bag on the front-passenger
side deploys under the following conditions:
Rthe OCS system detects that the front-
passenger seat is occupied or
Rthe seat belt buckle tongue is engaged in the belt buckle of the front-passenger seat
If the belt tongue is engaged in the belt buckle,
the side impact air bag on the front-passenger
side deploys if an appropriate accident situation
occurs. In this case, deployment is independent
of whether the front-passenger seat is occupied
or not.
Window curtain air bags
Occupant safety51
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Window curtain air bags:are integrated into
the side of the roof frame and deployed in the
area from the A-pillar to the C-pillar.
When deployed, the window curtain air bag
enhances the level of protection for the head.
However, it does not protect the chest or arms.
If the restraint system control unit detects a side
impact, the window curtain air bag is deployed
on the side on which the impact occurs.
If the system determines that they can offer
additional protection to that provided by the
seat belt, a window curtain air bag may be
deployed in other accident situations
(
Ypage 56).
Occupant Classification System
(OCS)
Introduction
The Occupant Classification System (OCS) cat-
egorizes the person in the front-passenger seat.
Depending on that result, the front-passenger
front air bag is either enabled or deactivated.
The system does not deactivate:
Rthe side impact air bag
Rthe window curtain air bag
Rthe Emergency Tensioning Devices
Requirements
To be classified correctly, the front passenger
must sit:
Rwith the seat belt fastened correctly
Rin an almost upright position with their back
against the seat backrest
Rwith their feet resting on the floor, if possible
If the front passenger does not observe these
conditions, OCS may produce a false classifica-
tion, e.g. because the front passenger:
Rtransfers their weight by supporting them-
selves on a vehicle armrest
Rsits in such a way that their weight is raised
from the seat cushion
If it is absolutely necessary to install a child
restraint system on the front-passenger seat, be
sure to observe the correct positioning of the
child restraint system. Never place objects
under or behind the child restraint system, e.g. a
cushion. Fully retract the seat cushion length.
The entire base of the child restraint system must always rest on the seat cushion of the
front-passenger seat. The backrest of the
forward-facing child restraint system must lie as
flat as possible against the backrest of the front-
passenger seat.
The child restraint system must not touch the
roof or be subjected to a load by the head
restraint. Adjust the angle of the seat backrest
and the head restraint position accordingly.
Only then can OCS be guaranteed to function
correctly. Always observe the child restraint sys-
tem manufacturer's installation and operating
instructions.
Occupant Classification System opera-
tion (OCS)
:PASSENGER AIR BAG ON indicator lamp
;PASSENGER AIR BAG OFF indicator lamp
The indicator lamps inform you whether the
front-passenger front air bag is deactivated or
enabled.
XPress the Start/Stop button once or twice, or turn the SmartKey to position 1or2 in the
ignition lock.
The system carries out self-diagnostics.
The PASSENGER AIR BAG OFF and PASSENGER
AIR BAG ON indicator lamps must light up simul-
taneously for approximately six seconds.
The indicator lamps display the status of the
front-passenger front air bag.
RPASSENGER AIR BAG ON lights up for 60 sec-
onds, subsequently both indicator lamps are
off (PASSENGER AIR BAG ON and OFF): the
front-passenger front air bag is able to deploy
in the event of an accident.
RPASSENGER AIR BAG OFF lights up: the front-
passenger front air bag is deactivated. It will
then not be deployed in the event of an acci-
dent.
52Occupant safety
Safety

If the PASSENGER AIR BAG ON indicator lamp is
off, only the PASSENGER AIR BAG OFF indicatorlamp shows the status of the front-passenger
front air bag. The PASSENGER AIR BAG OFF
indicator lamp may be lit continuously or be off.
If the status of the front-passenger front air bag
changes while the vehicle is in motion, an air bag
display message appears in the instrument clus-
ter (
Ypage 240). When the front-passenger
seat is occupied, always pay attention to the
PASSENGER AIR BAG OFF indicator lamp. Be
aware of the status of the front-passenger front
air bag both before and during the journey.
GWARNING
If the PASSENGER AIR BAG OFF indicator
lamp is lit, the front-passenger front air bag is
disabled. It will not be deployed in the event of
an accident and cannot perform its intended
protective function. A person in the front-
passenger seat could then, for example, come
into contact with the vehicle's interior, espe-
cially if the person is sitting too close to the
dashboard. This poses an increased risk of
injury or even fatal injury.
When the front-passenger seat is occupied,
always ensure that:
Rthe classification of the person in the front- passenger seat is correct and the front-
passenger front air bag is enabled or disa-
bled in accordance with the person in the
front-passenger seat
Rthe front-passenger seat has been moved
back as far back as possible.
Rthe person is seated correctly.
Make sure, both before and during the jour-
ney, that the status of the front-passenger
front air bag is correct.
GWARNING
If you secure a child in a rearward-facing child
restraint system on the front-passenger seat
and the PASSENGER AIR BAG OFF indicator
lamp is off, the front-passenger front air bag
may deploy in the event of an accident. The
child could be struck by the air bag. This poses an increased risk of injury or even fatal injury.
Make sure that the front-passenger front air
bag has been disabled. The PASSENGER AIR
BAG OFF indicator lamp must be lit.
If the PASSENGER AIR BAG OFF indicator lamp
stays off, do not install a rearward-facing child
restraint system on the front-passenger seat.
You can find more information on OCS under
"Problems with the Occupant Classification Sys-
tem" (
Ypage 55).
GWARNING
If you secure a child in a forward-facing child
restraint system on the front-passenger seat
and you position the front-passenger seat too close to the dashboard, in the event of an
accident, the child could:
Rcome into contact with the vehicle's inte-
rior if the PASSENGER AIR BAG OFF indi-
cator lamp is lit, for example
Rbe struck by the air bag if the PASSENGER
AIR BAG OFF indicator lamp is off
This poses an increased risk of injury or even fatal injury.
Always move the front-passenger seat as far
back as possible and fully retract the seat
cushion length. Always make sure that the
shoulder belt strap is correctly routed from
the vehicle belt sash guide to the shoulder
belt guide on the child restraint system. The
shoulder belt strap must be routed forwards
and downwards from the vehicle belt sash
guide. If necessary, adjust the vehicle belt
sash guide and the front-passenger seat
accordingly. Always observe the child
restraint system manufacturer's installation
instructions.
If OCS determines that:
Rthe front-passenger seat is unoccupied, the
PASSENGER AIR BAG OFF indicator lamp
lights up after the system self-test and
remains lit. This indicates that the front-
passenger front air bag is deactivated.
Rthe front-passenger seat is occupied by a
child of up to twelve months old, in a standard
child restraint system, the PASSENGER AIR
BAG OFF indicator lamp lights up after the
system self-test and remains lit. This indi-
Occupant safety53
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cates that the front-passenger front air bag is
deactivated.
But even in the case of a twelve-month-old
child, in a standard child restraint system, the
PASSENGER AIR BAG OFF indicator lamp can
go out after the system self-test. This indi-
cates that the front-passenger front air bag is
activated. The result of the classification is
dependent on, among other factors, the child
restraint system and the child's stature. It is
recommended that you install the child
restraint system on a suitable rear seat.
Rthe front-passenger seat is occupied by a per-
son with a smaller build (e.g. a teenager or
small adult), the PASSENGER AIR BAG OFF
indicator lamp lights up and remains lit after
the system self-test depending on the result
of the classification or, alternatively, goes out.
-if the PASSENGER AIR BAG OFF indicator
lamp is off, move the front-passenger seat
as far back as possible. Alternatively, a per-
son of smaller stature can sit on a rear seat.
-if the PASSENGER AIR BAG OFF indicator
lamp is lit, a person of smaller stature
should not use the front-passenger seat.
Rthe front-passenger seat is occupied by an
adult or a person of adult stature, the
PASSENGER AIR BAG OFF indicator lamp
goes out after the system self-test. This indi-
cates that the front-passenger front air bag is
activated.
If children are traveling in the vehicle, be sure to
observe the notes on "C hild
ren in the vehicle"
(Ypage 60).
When the Occupant Classification System
(OCS) is malfunctioning, the red 6restraint
system warning lamp on the instrument cluster
and the PASSENGER AIR BAG OFF indicator
lamp light up simultaneously. The front-
passenger front air bag is deactivated in this
case and does not deploy during an accident.
Have the Occupant Classification System (OCS)
checked and repaired immediately at a qualified
specialist workshop. Mercedes-Benz recom-
mends that you use an authorized Mercedes-
Benz Center for this purpose.
If the front-passenger seat, the seat cover or the
seat cushion are damaged, have the necessary
repair work carried out at a qualified specialist
workshop. Mercedes-Benz recommends that
you use an authorized Mercedes-Benz Center
for this purpose. For safety reasons, Mercedes-Benz recom-
mends that you only use seat accessories that
have been approved by Mercedes-Benz.
If the driver's air bag deploys, this does not
mean that the front-passenger front air bag will
also deploy. The Occupant Classification Sys-
tem (OCS) categorizes the occupant on the
front-passenger seat. Depending on that result,
the front-passenger front air bag is either ena-
bled or deactivated.
System self-test
GDANGER
If both the PASSENGER AIR BAG OFF and
PASSENGER AIR BAG ON indicator lamps do
not light up during the system self-test, the
system is malfunctioning. The front-
passenger front air bag might be triggered
unintentionally or might not be triggered at all
in the event of an accident with high deceler-
ation. This poses an increased risk of injury or
even fatal injury.
In this case the front-passenger seat may not
be used. Do not install a child restraint system
on the front-passenger seat. Have the Occu-
pant Classification System (OCS) checked
and repaired immediately at a qualified spe-
cialist workshop.
GWARNING
If the PASSENGER AIR BAG OFF indicator
lamp remains lit after the system self-test, the
front-passenger front air bag is disabled. It will
not be deployed in the event of an accident. In
this case, the front-passenger front air bag
cannot perform its intended protective func-
tion, e.g. when a person is seated in the front-
passenger seat.
That person could, for example, come into
contact with the vehicle's interior, especially
if the person is sitting too close to the dash-
board. This poses an increased risk of injury or
even fatal injury.
54Occupant safety
Safety