2016 MERCEDES-BENZ C CLASS length

Window curtain air bags
Window curtain air bags C 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.
In the event of 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
( Y
page 58).
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 disable: R
the side impact air bag R
the window curtain air bag R
the Emergency Tensioning Devices
Prerequisites
To be classified correctly, the front passenger
must sit: R
with the seat belt fastened correctly R
in an almost upright position with their back
against the seat backrest R
with 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: R
transfers their weight by supporting them-
selves on a vehicle armrest R
sits 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.
cushions. 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 instructions.
Occupant Classification System opera-
tion (OCS)
C
PASSENGER AIR BAG ON indicator lamp
D
PASSENGER AIR BAG OFF indicator lamp
The indicator lamps inform you whether the
front-passenger front air bag is deactivated or
enabled. X
Press the Start/Stop button once or twice, or
turn the SmartKey to position 1 or 2 in the
ignition lock.
The system carries out self-diagnostics.54
Occupant safety
Safety

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. R
PASSENGER AIR BAG ON lights up: the front-
passenger front air bag is enabled. If, in the
event of an accident, all deployment criteria
are met, the front-passenger front air bag is
deployed. R
PASSENGER 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.
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 ( Y
page 265). When the front-passenger
seat is occupied, always pay attention to the
PASSENGER AIR BAG ON and PASSENGER AIR
BAG OFF indicator lamps. Be aware of the status
of the front-passenger front air bag both before
and during the journey.
G WARNING
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: R
the 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 R
the front-passenger seat has been moved
back as far back as possible. R
the 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. G WARNING
If you secure a child in a rearward-facing child
restraint system on the front-passenger seat
and the PASSENGER AIR BAG ON indicator
lamp is lit up, the front-passenger front air bag
may deploy in 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
remains off and/or the PASSENGER AIR BAG
ON indicator lamp lights up, do not install a rear-
ward-facing child restraint system on the front-
passenger seat. You can find more information
on OCS under "Problems with the Occupant
Classification System" ( Y
page 58).
G WARNING
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: R
come into contact with the vehicle's inte-
rior if the PASSENGER AIR BAG OFF indi-
cator lamp is lit, for example R
be struck by the air bag if the PASSENGER
AIR BAG ON is lit up
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.Occupant safety 55
Safety Z

Problems with the Occupant Classification System (OCS) Be sure to observe the notes on "System self-test" ( Y
page 56).
Problem
Possible causes/consequences and P Solutions
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. X
Make sure the conditions for a correct classification of the person
on the front-passenger seat are met ( Y
page 54).X
If the PASSENGER AIR BAG OFF indicator lamp remains lit, the front-
passenger seat may not be used. X
Have 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: R
unoccupied R
occupied with the
weight of a child up to
twelve months old in a
child restraint system OCS is malfunctioning. X
Make sure there is nothing between the seat cushion and the child
seat. X
Make 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. X
Make sure that the seat cushion length is fully retracted. X
When 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. X
Check 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. X
Make sure that no objects are applying additional weight onto the
seat. X
If 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. X
Have OCS checked as soon as possible at an authorized Mercedes-
Benz Center.
Deployment of Emergency Tensioning
Devices and air bags
Important safety notes
G WARNING
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.
G WARNING
A deployed air bag no longer offers any pro-
tection and cannot provide the intended pro-58
Occupant safety
Safety

Always observe the child restraint system man-
ufacturer's installation and operating instruc-
tions.
Forward-facing child restraint system If it is absolutely necessary to install a forward-
facing child restraint system on the front-
passenger seat, always move the front-
passenger seat as far back as possible. 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 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. Always make sure that the shoul-
der belt strap is correctly routed from the vehi-
cle belt outlet to the shoulder belt guide on the
child restraint system. The shoulder belt strap
must be routed forwards and downwards from
the vehicle belt outlet. If necessary, adjust the
vehicle belt outlet and the front-passenger seat
accordingly.
Always observe the child restraint system man-
ufacturer's installation and operating instruc-
tions.
Child-proof locks
Important safety notes
G WARNING
If children are traveling in the vehicle, they
could: R
open doors, thus endangering other people
or road users R
exit the vehicle and be caught by oncoming
traffic R
operate vehicle equipment and become
trapped
There is a risk of an accident and injury.
Always activate the child-proof locks and
override feature if children are traveling in the
vehicle. When leaving the vehicle, always take
the key with you and lock the vehicle. Never
leave children unattended in the vehicle. Override feature for: R
the rear doors ( Y
page 67)R
the rear side windows ( Y
page 67)
G WARNING
If you leave children unsupervised in the vehi-
cle, they could set it in motion by, for example: R
release the parking brake. R
shift the automatic transmission out of the
parking position P .R
start 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.
G WARNING
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.
G WARNING
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.66
Children in the vehicle
Safety

The electric parking brake is also engaged auto-
matically if: R
DISTRONIC PLUS brings the vehicle to a
standstill or R
the HOLD function is keeping the vehicle sta-
tionary R
Active Parking Assist is keeping the vehicle
stationary
In addition, at least one of the following condi-
tions must be fulfilled: R
the engine is switched off R
the driver is not wearing a seat belt and the
driver's door is opened R
there is a system malfunction R
the power supply is insufficient R
the vehicle is stationary for a lengthy period
The red I (USA only) or $ (Canada only)
indicator lamp in the instrument cluster goes
out.
The electric parking brake is not automatically
engaged if the engine is switched off by the ECO
start/stop function.
Releasing automatically Your vehicle's electric parking brake is auto-
matically released if all of the following condi-
tions are met: R
the engine is running. R
the transmission is in position D or R .R
the seat belt has been fastened. R
you depress the accelerator pedal.
If the transmission is in position R , the trunk lid
must be closed.
If your seat belt is not fastened, the following
conditions must be fulfilled to automatically
release the electric parking brake: R
the driver's door is closed. R
you have shifted out of transmission position
P or you have previously driven faster than
2 mph (3 km/h).
Ensure that you do not depress the accelerator
pedal unintentionally. Otherwise the parking
brake will be released and the vehicle will start
to move. Emergency braking The vehicle can also be braked during an emer-
gency by using the electric parking brake. X
While driving, push handle C of the electric
parking brake ( Y
page 178).
The vehicle is braked as long as you keep
handle C of the electric parking brake
depressed. The longer electric parking brake
handle C is depressed, the greater the brak-
ing force.
During braking: R
a warning tone sounds R
the Please Release Parking Brake mes-
sage appears R
the red I (USA only) or $ (Canada
only) indicator lamp in the instrument cluster
flashes
When the vehicle has been braked to a stand-
still, the electric parking brake is engaged.
Parking the vehicle for a long period If you leave the vehicle parked for longer than
four weeks, the battery may be damaged by
exhaustive discharging.
If you leave the vehicle parked for longer than six
weeks, the vehicle may suffer damage as a
result of lack of use. X
Visit a qualified specialist workshop and seek
advice.
i You can obtain information about trickle
chargers from a qualified specialist work-
shop.
PLUG-IN HYBRID vehicles: observe the impor-
tant safety notes for the high-voltage battery
( Y
page 349).
Driving tips
General driving tips
Important safety notes
G WARNING
If you switch off the ignition while driving,
safety-relevant functions are only available
with limitations, or not at all. This could affect, Driving tips 179
Driving and parking Z

i If you select the 8 symbol in the display
and confirm with the controller, the split-
screen view appears.
Exiting 360° camera display mode The 360° camera display is stopped R
when you select transmission position P , orR
when you are driving at moderate speeds
The view which was active before the 360° cam-
era was displayed appears in the Audio 20 or
COMAND display. You can also stop the 360°
camera display split-screen view by selecting
the 8 symbol in the display and then con-
firming with the COMAND controller.
ATTENTION ASSIST
General notes ATTENTION ASSIST helps you during long,
monotonous journeys, such as on highways. It is
active in the 37 mph (60 km/h) to 125 mph
(200 km/h) range. If ATTENTION ASSIST
detects typical indicators of fatigue or increas-
ing lapses in concentration on the part of the
driver, it suggests taking a break.
Important safety notes ATTENTION ASSIST is only an aid to the driver. It
might not always recognize fatigue or increasing
inattentiveness in time or fail to recognize them
at all. The system is not a substitute for a well-
rested and attentive driver.
The functionality of ATTENTION ASSIST is
restricted and warnings may be delayed or not
occur at all: R
if the length of the journey is less than approx-
imately 30 minutes R
if the road condition is poor, e.g. if the surface
is uneven or if there are potholes R
if there is a strong side wind R
if you have adopted a sporty driving style with
high cornering speeds or high rates of accel-
eration R
if you are predominantly driving slower than
37 mph (60 km/h) or faster than 125 mph
(200 km/h) R
if you are driving with the active Steer Assist
of DISTRONIC PLUS R
if the time has been set incorrectly R
in active driving situations, such as when you
change lanes or change your speed
The ATTENTION ASSIST tiredness assessment
is deleted and restarted when continuing the
journey, if: R
you switch off the engine R
you take off your seat belt and open the driv-
er's door, e.g. for a change of drivers or to
take a break
Displaying the attention level
You can have current status information dis-
played in the assistance menu ( Y
page 247) of
the on-board computer. X
Select the Assistance display for Attention
Assist using the on-board computer
( Y
page 246).
The following information is displayed: R
length of the journey since the last break. R
the attention level determined by ATTENTION
ASSIST ( Attention Level ), displayed in a
bar display in five levels from high to low. R
If ATTENTION ASSIST is unable to calculate
the attention level and cannot issue a warn-
ing, the System Suspended message
appears. The bar display then changes the
display, e.g. if you are driving at a speed below
37 mph (60 km/h) or above 124 mph
(200 km/h).
Activating ATTENTION ASSIST X
Activate ATTENTION ASSIST using the on-
board computer ( Y
page 248).
The system determines the attention level of
the driver depending on the setting selected:214
Driving systems
Driving and parking

Observe the service intervals in the Mainte-
nance Booklet or contact a qualified specialist
workshop for more information.
! Always have work on batteries carried out at
a qualified specialist workshop. Should it, in
exceptional circumstances, be absolutely
necessary to disconnect the 12-volt battery
yourself, observe the following: R
secure the vehicle to prevent it from rolling
away. R
switch off the ignition. R
always disconnect the negative terminal
clamp first, followed by the positive termi-
nal clamp.
After the battery has been disconnected, the
transmission is locked in position P .
After the work has been done, install the bat-
tery and replace the cover of the positive ter-
minal clamp firmly.
Comply with safety precautions and take pro-
tective measures when handling batteries.
Risk of explosion.
Fire, open flames and smoking are
prohibited when handling the bat-
tery. Avoid creating sparks.
Electrolyte or battery acid is corro-
sive. Avoid contact with skin, eyes or
clothing.
Wear suitable protective clothing,
especially gloves, apron and face-
guard.
Immediately rinse electrolyte or acid
splashes off with clean water. Con-
tact a physician if necessary.
Wear eye protection.
Keep children away.
Observe this Operator's Manual.
For safety reasons, Mercedes-Benz recom-
mends that you only use batteries which have been tested and approved for your vehicle by
Mercedes-Benz. These batteries provide
increased impact protection to prevent vehicle
occupants from suffering acid burns should the
battery be damaged in the event of an accident.
In order for the battery to achieve the maximum
possible service life, it must always be suffi-
ciently charged.
The vehicle battery, like other batteries, can dis-
charge over time if you do not use the vehicle. In
this case, have the battery disconnected at a
qualified specialist workshop. You can also
charge the battery with a charger recommended
by Mercedes-Benz. Contact a qualified special-
ist workshop for further information.
Have the battery condition of charge checked
more frequently if you use the vehicle mainly for
short trips or if you leave it standing idle for a
lengthy period. Consult a qualified specialist
workshop if you wish to leave your vehicle
parked for a long period of time.
Remove the SmartKey if you park the vehicle
and do not require any electrical consumers.
The vehicle will then use very little energy, thus
conserving battery power.
PLUG-IN HYBRID vehicles: if the battery
charge is sufficient, the high-voltage battery can
also supply the 12 V battery. This only happens
if the condition of charge of the 12 V battery
requires this, e.g. after using electrical consum-
ers for an extended period with the engine
switched off. As the on-board voltage is contin-
uously monitored this can also be performed
when the engine is switched off. The condition of
charge of the 12 V battery and the on-board
voltage are thereby kept stable for a longer
period.
High-voltage battery – important
safety notes Only PLUG-IN HYBRID vehicles are equipped
with a high-voltage battery.
G DANGER
The vehicle's high-voltage electrical system is
under high voltage. If you modify components
in the vehicle's high-voltage electrical system
or touch damaged components, you may be
electrocuted. The components in the vehi-
cle's high-voltage electrical system may beBattery (vehicle) 349
Breakdown assistance Z

damaged in an accident, although the damage
is not visible. There is a risk of fatal injury.
Following an accident, do not touch any high-
voltage components and never modify the
vehicle's high-voltage electrical system. Have
the vehicle towed away after an accident and
the vehicle's high-voltage electrical system
checked by a qualified specialist workshop.
G WARNING
In the event of a vehicle fire, the internal pres-
sure of the high-voltage battery can exceed a
critical value. In this case flammable gas
escapes through a ventilation valve on the
underbody. The gas can ignite. There is a risk
of injury.
Leave the danger zone immediately. Secure
the danger area at a suitable distance, whilst
observing legal requirements.
G WARNING
If the housing of the high-voltage battery has
been damaged, electrolyte and gases may
leak out. These are poisonous and caustic.
There is a risk of injury.
Avoid contact with skin, eyes or clothing.
Immediately rinse electrolyte splashes off
with water and seek medical attention
straight away.
! Exhaustive discharge caused by the vehicle
standing idle for lengthy periods can damage
the high-voltage battery. If the vehicle is idle
for lengthy periods leave the high-voltage bat-
tery connected to a charging station.
Consult an authorized Mercedes-Benz Center if
you wish to leave your vehicle parked for a long
period of time.
Charging the 12 V battery
Vehicles with a lithium-ion battery:
! Only use battery chargers with a maximum
charging voltage of 14.4 V.
All other vehicles: G WARNING
During charging and jump-starting, explosive
gases can escape from the battery. There is a
risk of an explosion.
Particularly avoid fire, open flames, creating
sparks and smoking. Ensure there is sufficient
ventilation while charging and jump-starting.
Do not lean over a battery.
G WARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with skin, eyes or clothing. Do
not inhale any battery gases. Do not lean over
the battery. Keep children away from batter-
ies. Wash away battery acid immediately with
plenty of clean water and seek medical atten-
tion.
G WARNING
A discharged battery can freeze at tempera-
tures below freezing point. When jump-start-
ing the vehicle or charging the battery, gases
can escape from the battery. There is a risk of
an explosion.
Allow the frozen battery to thaw out before
charging it or jump-starting.
! Only use battery chargers with a maximum
charging voltage of 14.8 V.
All vehicles:
! Only charge the battery using the jump-
starting connection point.
The jump-starting connection point is in the
engine compartment ( Y
page 352).X
Open the hood. X
Connect the battery charger to the positive
terminal and ground point in the same order
as when connecting the donor battery in the
jump-starting procedure ( Y
page 352).
Keep away from fire and open flames. Do not
lean over a battery. Never charge the battery if it
is still installed in the vehicle, unless you use a
battery charger which has been tested and
approved by Mercedes-Benz. A battery charger
unit specially adapted for Mercedes-Benz vehi-
cles and tested and approved by Mercedes-
Benz is available as an accessory. It permits the350
Battery (vehicle)
Breakdown assistance