2018 MERCEDES-BENZ C CLASS Owners Manual

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 person is seated properly with a cor-
rectly fastened seatbelt
Rthe front-passenger seat has been moved
as far back as possible
If the PASSENGER AIR BAG OFF indicator
lamp remains lit when it should not, the front-
passenger seat may not be used. Do not
install a child restraint system on the front-
passenger seat. Have the Occupant Classifi-
cation System (OCS) checked and repaired
immediately at a qualified specialist work-
shop.
GWARNING
Objects between the seat surface and the
child restraint system could affect OCS oper- ation. This could result in the front-passenger
air bag not functioning as intended during an
accident. This poses an increased risk of
injury or even fatal injury.
Do not place any objects between the seat
surface and the child restraint system. 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, as far as
possible, be resting on the backrest of the
front-passenger seat. Always comply with the
child restraint system manufacturer's instal-
lation instructions.
After the system self-test, the PASSENGER AIR
BAG OFF or PASSENGER AIR BAG ON indicator
lamp displays the status of the front-passenger
front air bag (
Ypage 52). If the front-passenger
front air bag is enabled, the PASSENGER AIR
BAG ON indicator lamp lights up for 60 seconds
and then goes out.
If the PASSENGER AIR BAG ON indicator lamp is off, only the PASSENGER AIR BAG OFF indicator
lamp shows the status of the front-passenger
front air bag. The PASSENGER AIR BAG OFF
indicator lamp may be lit continuously or be off.
For more information about the OCS, see "Prob-
lems with the Occupant Classification System"
(
Ypage 55).
Problems with the Occupant Classification System (OCS)
Be sure to observe the notes on "System self-test" (Ypage 54).
Occupant safety55
Safety
Z

ProblemPossible causes/consequences andMSolutions
The PASSENGER AIR
BAG OFF indicator lamp
lights up and remains lit,
even though the front-
passenger seat is occu-
pied by an adult or a per-
son of a stature corre-
sponding to that of an
adult.The classification of the person on the front-passenger seat is incor-
rect.
XMake sure the conditions for a correct classification of the person
on the front-passenger seat are met (Ypage 52).
XIf the PASSENGER AIR BAG OFF indicator lamp remains lit, the front-
passenger seat may not be used.
XHave OCS checked as soon as possible at an authorized Mercedes- Benz Center.
The PASSENGER AIR
BAG OFF indicator lamp
does not light up and/or
does not stay on.
The front-passenger seat
is:
Runoccupied
Roccupied with the
weight of a child up to
twelve months old in a
child restraint system
OCS is malfunctioning.
XMake sure there is nothing between the seat cushion and the child
seat.
XMake sure that the entire base of the child restraint system rests 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. If necessary,
adjust the position of the front-passenger seat.
XMake sure that the seat cushion length is fully retracted.
XWhen installing the child restraint system, make sure that the seat
belt is tight. Do not pull the seat belt tight using the front-passenger seat adjustment. This could result in the seat belt and the child
restraint system being pulled too tightly.
XCheck for correct installation of the child restraint system.
Make sure that the head restraint does not apply a load to the child
restraint system. If necessary, adjust the head restraint accord-
ingly.
XMake sure that no objects are applying additional weight onto the
seat.
XIf the PASSENGER AIR BAG OFF indicator lamp remains off and/or
the PASSENGER AIR BAG ON indicator lamp lights up, do not install a child restraint system on the front-passenger seat. It is recom-
mended that you install the child restraint system on a suitable rear
seat.
XHave OCS checked as soon as possible at an authorized Mercedes-Benz Center.
Deployment of Emergency Tensioning
Devices and air bags
Important safety notes
GWARNING
The air bag parts are hot after an air bag has
been deployed. There is a risk of injury.
Do not touch the air bag parts. Have a
deployed air bag replaced at a qualified spe-
cialist workshop as soon as possible.
GWARNING
A deployed air bag no longer offers any pro-
tection and cannot provide the intended pro-
tection in an accident. There is an increased
risk of injury.
Have the vehicle towed to a qualified special-
ist workshop in order to have a deployed air
bag replaced.
It is important for your safety and that of your
passenger to have deployed air bags replaced
56Occupant safety
Safety

and to have any malfunctioning air bags
repaired. This will help to make sure the air bags
continue to perform their protective function for
the vehicle occupants in the event of a crash.
GWARNING
Emergency Tensioning Devices that have
deployed pyrotechnically are no longer opera-
tional and are unable to perform their inten-
ded protective function. This poses an
increased risk of injury or even fatal injury.
Have pyrotechnically triggered Emergency
Tensioning Devices replaced immediately at a
qualified specialist workshop.
An electric motor is used by PRE-SAFE
®to trig-
ger the tightening of the seat belt in hazardous
situations. This procedure is reversible.
If Emergency Tensioning Devices are triggered
or air bags are deployed, you will hear a bang,
and some powder may also be released. The
6 restraint system warning lamp lights up.
Only in rare cases will the bang affect your hear-
ing. The powder that is released generally does
not constitute a health hazard, but it may cause short-term breathing difficulties in people with
asthma or other respiratory problems. Provided
it is safe to do so, you should leave the vehicle
immediately or open the window in order to pre-
vent breathing difficulties.
Air bags and pyrotechnic Emergency Tensioning
Devices (ETDs) contain perchlorate material,
which may require special handling and regard
for the environment. National guidelines must
be observed during disposal. In California, see
www.dtsc.ca.gov/HazardousWaste/
Perchlorate/index.cfm.
Method of operation
During the first stage of a collision, the restraint
system control unit evaluates important physi-
cal data relating to vehicle deceleration or accel-
eration, such as:
Rduration
Rdirection
Rintensity
Based on the evaluation of this data, the
restraint system control unit triggers the Emer-
gency Tensioning Devices during a frontal or
rear collision. An Emergency Tensioning Device can only be
triggered, if:
Rthe ignition is switched on
Rthe components of the restraint system are
operational. You can find further information
under "Restraint system warning lamp"
(
Ypage 45)
Rthe seat belt buckle tongue has engaged in
the belt buckle of the respective front seat
The Emergency Tensioning Devices in the rear
compartment are triggered independently of the
lock status of the seat belts.
If the restraint system control unit detects a
more severe accident, further components of
the restraint system are activated independ-
ently of each other in certain frontal collision
situations:
RFront air bags and driver's knee bag
RWindow curtain air bag, if the system deter-
mines that deployment can offer additional
protection to that provided by the seat belt
The front-passenger front air bag is activated or
deactivated depending on the person on t
he
front-passenger seat. The front-passenger front
air bag can only deploy in an accident if the
PASSENGER AIR BAG OFF indicator lamp is off.
Observe the information on the PASSENGER AIR
BAG indicator lamps (
Ypage 45).
Your vehicle has two-stage front air bags. In the
first deployment stage, the front air bag is filled
with propellant gas. The front air bag is fully
deployed with the maximum amount of propel-
lant gas if a second deployment threshold is
reached within a few milliseconds.
The activation threshold of the Emergency Ten-
sioning Devices and the air bags is determined
by evaluating the rate of vehicle deceleration or
acceleration which occurs at various points in
the vehicle. This process is pre-emptive in
nature. Deployment should take place in good
time at the start of the collision.
The rate of vehicle deceleration or acceleration
and the direction of the force are essentially
determined by:
Rthe distribution of forces during the collision
Rthe collision angle
Rthe deformation characteristics of the vehicle
Rthe characteristics of the object with which
the vehicle has collided
Factors which can only be seen and measured
after a collision has occurred do not play a deci-
sive role in the deployment of an air bag. Nor do
Occupant safety57
Safety
Z

they provide an indication of air bag deploy-
ment.
The vehicle can be deformed considerably, with-
out an air bag being deployed. This is the case if
only parts which are relatively easily deformed
are affected and the rate of deceleration is not
high. Conversely, air bags may be deployed eventhough the vehicle suffers only minor deforma-
tion. This is the case if, for example, very rigid
vehicle parts such as longitudinal body mem-
bers are hit, and sufficient deceleration occurs
as a result.
If the restraint system control unit detects a side
impact or if the vehicle rolls over, the applicable
components of the restraint system are activa-
ted independently of each other depending on
the apparent type of accident.
RSide impact air bags on the side where the
impact takes place, independently of the
Emergency Tensioning Device and the use of
the seat belt on the driver's seat and outer
seats in the second row
The side impact air bag on the front-
passenger side deploys under the following
conditions:
-the OCS system detects that the front-
passenger seat is occupied or
-the seat belt buckle tongue is engaged in
the belt buckle of the front-passenger seat
RWindow curtain air bag on the side of impact, independently of the use of the seat belt and
independently of whether the front-
passenger seat is occupied
RFront Emergency Tensioning Devices, if the
system determines that deployment can offer
additional protection for the vehicle occu-
pants in this situation
RRear Emergency Tensioning Devices in cer-
tain situations if the vehicle rolls over
RWindow curtain air bags on the driver's and
front-passenger side in certain situations
when the vehicle rolls over, if the system
determines that deployment can offer addi-
tional protection to that provided by the seat
belt
iNot all air bags are deployed in an accident.
The different air bag systems work independ-
ently of each other. How the air bag system works is determined
by the severity of the accident detected,
especially the vehicle deceleration or accel-
eration and the apparent type of accident:
RFrontal collision
RSide impact
RRollover
PRE-SAFE®(anticipatory occupant
protection system)
Introduction
In certain hazardous situations, PRE-SAFE®
takes pre-emptive measures to protect the vehi-
cle occupants.
Important safety notes
!Make sure that there are no objects in the
footwell or behind the seats. There is a danger that the seats and/or objects could be dam-
aged when PRE-SAFE
®is activated.
Despite your vehicle being equipped with the
PRE-SAFE
®system, the possibility of personal
injuries occurring as a result of an accident can-
not be eliminated. Always adapt your driving
style to suit the prevailing road and weather
conditions and maintain a safe distance from
the vehicle in front. Drive carefully.
Function
PRE-SAFE®intervenes:
Rin emergency braking situations, e.g. when
BAS is activated
Rin critical driving situations, e.g. when physi-
cal limits are exceeded and the vehicle under-
steers or oversteers severely
Rvehicles with the Driving Assistance package:
when a driver assistance system intervenes
powerfully or the radar sensor system detects
an imminent danger of collision in certain sit- uations
58Occupant safety
Safety

PRE-SAFE®takes the following measures
depending on the hazardous situation detected:
Rthe front seat belts are pre-tensioned.
Rif the vehicle skids, the side windows and the
sliding sunroof are closed.
Rvehicles with the memory function for the
front-passenger seat: the front-passenger
seat is adjusted if it is in an unfavorable posi-
tion.
If the hazardous situation passes without result-
ing in an accident, PRE-SAFE
®slackens the belt
pre-tensioning. All settings made by PRE-SAFE®
can then be reversed.
If the seat belt pre-tensioning is not reduced:
XMove the seat backrest or seat back slightly
when the vehicle is stationary.
The seat belt pre-tensioning is reduced and
the locking mechanism is released.
The seat-belt adjustment is an integral part of
the PRE-SAFE
®convenience function. Informa-
tion about the convenience function can be
found under "Belt adjustment" (
Ypage 48).
PRE-SAFE®PLUS (anticipatory occu-
pant protection system PLUS)
Introduction
PRE-SAFE®PLUS is only available in vehicles
with the Driving Assistance package.
Using the radar sensor system, PRE-SAFE
®
PLUS is able to detect that a head-on or rear-end
collision is imminent. In certain hazardous sit-
uations, PRE-SAFE
®PLUS takes pre-emptive
measures to protect the vehicle occupants.
Important safety notes
The intervention of PRE-SAFE®PLUS cannot
prevent an imminent collision.
The driver is not warned about the intervention
of PRE-SAFE
®PLUS.
PRE-SAFE®PLUS does not intervene if the vehi-
cle is backing up.
When driving, or when parking or exiting a park-
ing space with assistance from Parking Pilot,
PRE-SAFE
®PLUS will not apply the brakes.
Function
PRE-SAFE®PLUS intervenes in certain situa-
tions if the radar sensor system detects an
imminent head-on or rear-end collision.
PRE-SAFE
®PLUS takes the following measures
depending on the hazardous situation detected:
Rif the radar sensor system detects that a
head-on collision is imminent, the seat belts
are pre-tensioned.
Rif the radar sensor system detects that a rear-
end collision is imminent:
-the brake pressure is increased if the driver
applies the brakes when the vehicle is sta- tionary.
-the seat belts are pre-tensioned.
The PRE-SAFE®PLUS braking application is can-
celed:
Rif the accelerator pedal is depressed when a
gear is engaged
Rif the risk of a collision passes or is no longer
detected
Rif Distance Pilot DISTRONIC indicates an
intention to pull away
If the hazardous situation passes without result-
ing in an accident, the original settings are
restored.
Automatic measures after an acci-
dent
Immediately after an accident, the following
measures are implemented, depending on the
type and severity of the impact:
Rthe hazard warning lamps are switched on
Rthe emergency lighting is activated
Rthe vehicle doors are unlocked
Rthe front side windows are lowered
Rvehicles with a memory function: the electri-
cally adjustable steering wheel is raised when
the driver's door is opened
Rthe engine is switched off and the fuel supply
is cut off
Rvehicles with mbrace: automatic emergency
call
Occupant safety59
Safety
Z

Children in the vehicle
Important safety notes
Accident statistics show that children secured
in the rear seats are safer than children secured
in the front-passenger seat. For this reason,
Mercedes-Benz strongly advises that you install
a child restraint system on a rear seat. Children are generally better protected there.
If a child younger than twelve years old and
under 5 ft (1.50 m) in height is traveling in the
vehicle:
Ralways secure the child in a child restraint
system suitable for Mercedes-Benz vehicles.
The child restraint system must be appropri-
ate to the age, weight and size of the child
Rbe sure to observe the instructions and safety
notes in this section in addition to the child
restraint system manufacturer's installation
instructions
Rbe sure to observe the instructions and safetynotes on the "Occupant classification system
(OCS)" (
Ypage 52)
GWARNING
If you leave children unsupervised in the vehi-
cle, they could set it in motion by, for example:
Rrelease the parking brake.
Rshift the automatic transmission out of the
parking position P.
Rstart the engine.
In addition, they may operate vehicle equip-
ment and become trapped. There is a risk of
an accident and injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children unsupervised in the vehicle.
GWARNING
If persons, particularly children are subjected to prolonged exposure to extreme heat or
cold, there is a risk of injury, possibly even
fatal. Never leave children unattended in the
vehicle.
GWARNING
If the child restraint system is subjected to
direct sunlight, parts may get very hot. Chil-
dren may burn themselves on these parts,
particularly on the metal parts of the child
restraint system. There is a risk of injury.
If you leave the vehicle, taking the child with
you, always ensure that the child restraint
system is not exposed to direct sunlight. Pro- tect it with a blanket, for example. If the child
restraint system has been exposed to direct
sunlight, let it cool down before securing the
child in it. Never leave children unattended in
the vehicle.
Always ensure that all vehicle occupants have
their seat belts fastened correctly and are sitting
properly. Particular attention must be paid to
children.
Observe the safety notes on the seat belt
(
Ypage 46 )and the notes on correct use of seat
belts (Ypage 47).
A booster seat may be necessary to achieve
proper seat belt positioning for children over
41 lb s(18 kg) until they reach a height where a
three-point seat belt can be properly fastened
without a booster seat.
Special seatbelt retractor
GWARNING
If the seat belt is released while driving, the
child restraint system will no longer be
secured properly. The special seat belt retrac- tor is disabled and the inertia real draws in a
portion of the seat belt. The seat belt cannot
be immediately refastened. There is an
increased risk of injury, possibly even fatal.
Stop the vehicle immediately, paying atten-
tion to road and traffic conditions. Reactivate
the special seat belt retractor and secure the
child restraint system properly.
All seat belts in the vehicle, except the driver's
seat belt, are equipped with a special seat belt
retractor. When activated, the special seat belt
retractor ensures that the seat belt cannot
slacken once the child seat is secured.
60Children in the vehicle
Safety

Installing a child restraint system:
XMake sure you observe the child restraint
system manufacturer's installation instruc-
tions.
XPull the seat belt smoothly from the belt out-
let.
XEngage seat belt tongue in belt buckle.
Activating the special seat belt retractor:
XPull the seat belt out fully and let the inertia
reel retract it again.
While the seat belt is retracting, you should
hear a ratcheting sound. The special seat belt
retractor is enabled.
XPush the child restraint system down so that
the seat belt is tight and does not loosen.
Removing the child restraint system and deac-
tivating the special seat belt retractor:
XMake sure you observe the child restraint
system manufacturer's installation instruc-
tions.
XPress the release button of the seat belt
buckle and guide the seat belt tongue back
towards the belt sash guide.
The special seat belt retractor is deactivated.
Child restraint system
The use of seat belts and child restraint systems
is required by law in:
Rall 50 states
Rthe U.S. territories
Rthe District of Columbia
Rall Canadian provinces
You can obtain further information about the
correct child restraint system from any author-
ized Mercedes-Benz Center.
GWARNING
If the child restraint system is installed incor-
rectly on a suitable seat, it cannot protect as
intended. The child cannot then be restrained
in the event of an accident, heavy braking or
sudden changes of direction. There is an
increased risk of injury, possibly even fatal.
Make sure that you observe the child restraint
system manufacturer's installation instruc-
tions and the notes on use. Please ensure,
that the base of the child restraint system is
always resting completely on the seat cush-
ion. Never place objects, e.g. cushions, under or behind the child restraint system. Only use
child restraint systems with the original cover
designed for them. Only replace damaged
covers with genuine covers.
GWARNING
If the child restraint system is installed incor-
rectly or is not secured, it can come loose in
the event of an accident, heavy braking or a
sudden change in direction. The child
restraint system could be thrown about, strik-
ing vehicle occupants. There is an increased
risk of injury, possibly even fatal.
Always install child restraint systems prop-
erly, even if they are not being used. Make
sure that you observe the child restraint sys-
tem manufacturer's installation instructions.
You will find further information on stowing
objects, luggage or loads under "Loading guide-
lines" (
Ypage 280).
GWARNING
Child restraint systems or their securing sys-
tems which have been damaged or subjected
to a load in an accident can no longer protect
as intended. The child cannot then be
restrained in the event of an accident, heavy
braking or sudden changes of direction. There is an increased risk of injury, possibly even
fatal.
Replace child restraint systems which have
been damaged or subjected to a load in an
accident as soon as possible. Have the secur-
ing systems on the child restraint system
checked at a qualified specialist workshop,
before you install a child restraint system
again.
The securing systems of child restraint systems
are:
Rthe seat belt system
Rthe LATCH-type (ISOFIX) securing rings
Rthe Top Tether anchorages
If it is absolutely necessary to carry a child on
the front-passenger seat, be sure to observe the
Children in the vehicle61
Safety
Z

information on the "Occupant Classification
System (OCS)" (Ypage 52). There you will also
find information on deactivating the front-
passenger front air bag.
All child restraint systems must meet the fol-
lowing standards:
RU.S. Federal Motor Vehicle Safety Standards
213 and 225
RCanadian Motor Vehicle Safety Standards
213 and 210.2
Confirmation that the child restraint system cor-
responds to the standards can be found on an
instruction label on the child restraint system.
This confirmation can also be found in the instal-
lation instructions that are included with the
child restraint system.
Observe the warning labels in the vehicle inte-
rior and on the child restraint system.
LATCH-type (ISOFIX) child seat secur-
ing system
GWARNING
LATCH-type (ISOFIX) child restraint systems
do not offer sufficient protection for children
whose weight combined with the child
restraint system is greater than 65 lbs (29 kg) and who are secured using the safety belt
integrated in the child restraint system. In the
event of an accident, a child might not be
restrained correctly. This poses an increased
risk of injury or even fatal injury.
If the child and the child restraint system
together weigh more than 65 lbs (29 kg), only
use LATCH-type (ISOFIX) child restraint sys-
tems with which the child is also secured with
the vehicle seat belt. Also secure the child
restraint system with the Top Tether belt, if
available.
Always comply with the manufacturer's instal-
lation and operating instructions for the child
restraint system used.
Before every trip, make sure that the LATCH-
type (ISOFIX) child restraint system is engaged
correctly in both LATCH-type (ISOFIX) securing
rings
!When installing the child restraint system,
make sure that the seat belt for the middle seat does not get trapped. The seat belt could
otherwise be damaged.
Vehicles with rear seat armrest: adjust the
rear seat armrest so that LATCH-type (ISOFIX)
securing rings :for the LATCH-type (ISOFIX)
child restraint system are accessible.
XInstall the LATCH-type (ISOFIX) child restraint
system on both LATCH-type (ISOFIX) securing
rings :.
ISOFIX is a standardized securing system for
specially designed child restraint systems on
the rear seats. LATCH-type (ISOFIX) securing
rings for two LATCH-type (ISOFIX) child restraint
systems are installed on the left and right of the
rear seats.
Non-LATCH-type (ISOFIX) child seats may also
be used and can be installed using the vehicle's
seat belt system. Install the child seat according
to the manufacturer's instructions.
Top Tether
Introduction
Top Tether provides an additional connection
between the LATCH-type (ISOFIX) child restraint system secured with a LATCH-type (ISOFIX) sys-
tem and the vehicle. This helps reduce the risk of
injury even further. If the child restraint system
is equipped with a Top Tether belt, this should
always be used.
Important safety notes
GWARNING
If the rear seat backrests are not locked, they
could fold forwards in the event of an acci-
dent, heavy braking or sudden changes of
direction. As a result, child restraint systems
62Children in the vehicle
Safety