MERCEDES-BENZ CLA 2017 Workshop Manual

If children are traveling in the vehicle, be sure to
observe the notes on "Children in the vehicle"
( Y
page 53).
When the occupant classification system (OCS)
is malfunctioning, the red u restraint system
warning lamp in 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 recommends 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 in the front-
passenger seat. Depending on that result, the
front-passenger front air bag is either enabled or
deactivated.
System self-test
G DANGER
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. G WARNING
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.
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 person is seated properly with a cor-
rectly fastened seatbelt R
the 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.
G WARNING
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-Occupant safety 49
Safety Z

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 ( Y
page 47). 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"
( Y
page 50).
Problems with the Occupant Classification System (OCS) Be sure to observe the notes on "System self-test" ( Y
page 49).50
Occupant safety
Safety

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 47).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-
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 replacedOccupant safety 51
Safety Z

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.
G WARNING
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.
If Emergency Tensioning Devices are triggered
or air bags are deployed, you will hear a bang,
and a small amount of powder may also be
released. The u 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: R
duration R
direction R
intensity
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: R
the ignition is switched on R
the components of the restraint system are
operational. You can find further information
under: "Restraint system warning lamp"
( Y
page 40) R
the 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: R
Front air bags as well as driver's and front-
passenger knee bags R
Window 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
deactiv ated dependin g
on the person on the
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 ( Y
page 40).
Your vehicle has two-stage front air bags. During
the first deployment stage, the front air bag is
filled with propellant gas to reduce the risk of
injuries. The front air bag is fully deployed with
the maximum amount of propellant gas if a sec-
ond deployment threshold is reached within a
few milliseconds.
The activation threshold of the Emergency Ten-
sioning Devices and the air bag are 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: R
the distribution of forces during the collision R
the collision angle R
the deformation characteristics of the vehicle R
the characteristics of the object with which
the vehicle has collided52
Occupant safety
Safety

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
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 even
though 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. R
Side 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 R
Window curtain air bag on the side of impact,
independently of the u se of the seat belt and
independently of whether the front-
passenger seat is occupied R
Emergency Tensioning Devices, if the system
determines that deployment can offer addi-
tional protection in this situation R
Window 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
i Not 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: R
Frontal collision R
Side impact R
Rollover
Automatic measures after an acci-
dent Immediately after an accident, the following
measures are implemented, depending on the
type and severity of the impact: R
the hazard warning lamps are activated R
the emergency lighting is activated R
the vehicle doors are unlocked R
the front side windows are lowered R
the engine is switched off and the fuel supply
is cut off R
vehicles with mbrace: automatic emergency
call
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: R
always 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 R
be sure to observe the instructions and safety
notes in this section in addition to the child
restraint system manufacturer's installation
instructions R
be sure to observe the instructions and safety
notes on the "Occupant classification system
(OCS)" ( Y
page 46)Children in the vehicle 53
Safety Z

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.
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
( Y
page 41) and the notes on correct use of seat
belts ( Y
page 42).
A booster seat may be necessary to achieve
proper seat belt positioning for children over
41 lbs (18 kg) until they reach a height where a three-point seat belt can be properly fastened
without a booster seat.
Special seat belt retractor
G WARNING
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 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 will not slacken once
the child restraint system has been secured.
Installing a child restraint system: X
Always comply with the child restraint system
manufacturer's installation instructions. X
Pull the seat belt smoothly from the belt out-
let. X
Engage the seat belt tongue in the belt buckle.
Activating the special seat belt retractor: X
Pull 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 activated. X
Push the child seat restraint system down so
that the seat belt is tight and does not loosen.
Removing a child restraint system and deacti-
vating the special seat belt retractor: X
Always comply with the child restraint system
manufacturer's installation instructions. X
Press the release button of the belt buckle,
hold the belt tongue firmly and guide it back
towards the belt outlet.
The special seat belt retractor is deactivated.54
Children in the vehicle
Safety

Child restraint system The use of seat belts 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
If you install a rearward-facing child restraint
system on the center rear seat, the rear arm rest
must be folded back as far as possible.
You can obtain further information about the
correct child restraint system from any author-
ized Mercedes-Benz Center.
G WARNING
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.
G WARNING
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" ( Y
page 233). G WARNING
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: R
the seat belt system R
the LATCH-type (ISOFIX) securing rings R
the Top Tether anchorages
If it is absolutely necessary to carry a child on
the front-passenger seat, be sure to observe the
information on the "Occupant Classification
System (OCS)" ( Y
page 46). There you will also
find information on deactivating the front-
passenger front air bag.
All child restraint systems must meet the fol-
lowing standards: R
U.S. Federal Motor Vehicle Safety Standards
213 and 225 R
Canadian Motor Vehicle Safety Standards
213 and 210.2
Confirmation that the child restraint system cor-
responds to the standards can be f ound on an
in struction 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.Children in the vehicle 55
Safety Z

LATCH-type (ISOFIX) child seat secur-
ing system
G WARNING
LATCH-type (ISOFIX) child restraint systems
do not offer sufficient protective effect for
children whose weight is greater than 48 lbs
(22 kg) 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 weighs more than 48 lbs (22 kg),
only use LATCH-type (ISOFIX) child restraint
systems 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.
X
Install the LATCH-type (ISOFIX) child restraint
system on both LATCH-type (ISOFIX) securing
rings C .
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 child restraint system secured with
a LATCH-type (ISOFIX) system 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
G WARNING
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
cannot perform their intended protective
function. Rear seat backrests that are not
locked can also cause additional injuries, e.g.
in the event of an accident. This poses an
increased risk of injury or even fatal injury.
Always lock rear seat backrests after instal-
ling a Top Tether belt. Observe the lock veri-
fication indicator. Adjust the rear seat backr-
ests so that they are in an upright position.
If the rear backrest is not engaged and locked,
the red lock verification indicator will be visible
( Y
page 236).56
Children in the vehicle
Safety

Top Tether anchorages
The Top Tether anchorage points are installed in
the rear compartment behind the head
restraints on the parcel shelf. X
Press down the rear of cover D in the direc-
tion of the arrow.
Cover D is raised slightly at the front.X
Fold cover D upwards.
Vehicles with adjustable head restraints: X
Move head restraint C upwards.X
Route Top Tether belt

Rearward-facing child restraint system If it is absolutely necessary to install a rearward-
facing child restraint system on the front-
passenger seat, always make sure that the
front-passenger front air bag is deactivated.
Only if the PASSENGER AIR BAG OFF indicator
lamp is permanently lit ( Y
page 40) is the front-
passenger front air bag deactivated.
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 59)R
the rear side windows ( Y
page 59)
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.58
Children in the vehicle
Safety