MERCEDES-BENZ CLA-Class 2014 C117 Service Manual

Useful information
..............................40
Panic alarm .......................................... 40
Occupant safety .................................. 40
Children in the vehicle ........................56
Driving safety systems .......................63
Theft deterrent locking system .........72 39Safety

Useful information
i This Operator's manual describes all
models and all standard and optional equip- ment of your vehicle available at the time of
publication of the Operator's manual.
Country-specific differences are possible.
Please note that your vehicle may not be
equipped with all features described. This
also applies to safety-related systems and
functions.
i Read the information on qualified special-
ist workshops (Y page 26). Panic alarm
X
To activate: press0033button 0043for at
least one second.
An alarm sounds and the exterior lighting
flashes.
X To deactivate: press0033button 0043
again.
or
X Insert the SmartKey into the ignition lock. Occupant safety
Important safety notes
G
WARNING
Modifications to the restraint systems could
result in them not functioning properly any
more. The restraint systems could then no
longer protect vehicle occupants as they are designed to do and could fail in the event of an
accident or activate unexpectedly, for exam-
ple. There is an increased risk of injury.
Never modify parts of the restraint systems.
Do not attempt to modify the wiring as well as
electronic components or their software.
If it is necessary to modify an air bag system to accommodate a person with disabilities, con-tact an authorized Mercedes-Benz center.
USA only: for further information contact our
Customer Assistance Center at
1-800-FOR-MERCedes (1800-367-6372).
In this section, you will learn the most impor- tant facts about the restraint system compo-
nents of the vehicle.
The restraint system consists of:
R Seat belts
R Child restraint systems
R LATCH-type (ISOFIX) child seat securing
system
Additional protection is provided by:
R SRS (Supplemental Restraint System)
R Air bag system components with:
- PASSENGER AIR BAG OFF indicator lamp
- Front-passenger seat with Occupant
Classification System (OCS)
Although the systems are independent, their
protective functions work in conjunction with each other. Not all air bags are always
deployed in an accident.
i For information on infants and children
traveling with you in the vehicle restraint
systems for infants and children, see "Chil-
dren in the vehicle" (Y page 56). SRS (Supplemental Restraint System)
Introduction Supplemental Restraint System (SRS) with:
R The 0075 SRS warning lamp
R Air bags
R Air bag control unit (with crash sensors) 40
Occupant safetySafety

R
Emergency Tensioning Devices for the
front seat belts and the outer seat belts in
the rear
R Seat belt force limiter for the front seat
belts and the outer seat belts in the rear
SRS reduces the risk of vehicle occupants
coming into contact with parts of the vehi-
cle's interior in the event of an accident. It can
also reduce the forces to which vehicle occu-
pants are subjected during an accident.
SRS warning lamp G
WARNING
If SRS is malfunctioning, restraint system
components may be triggered unintentionally
or might not be triggered at all in the event of
an accident with a high rate of vehicle decel-
eration. There is an increased risk of injury,
possibly even fatal.
Have SRS checked and repaired immediately
at a qualified specialist workshop.
SRS functions are checked regularly when
you switch on the ignition and when the
engine is running. Therefore, malfunctions
can be detected in good time.
The 0075 SRS warning lamp in the instrument
cluster lights up when the ignition is switched on. It goes out no later than a few seconds
after the engine is started.
The SRS components are in operational read-
iness when the 0075SRS indicator lamp goes
out while the engine is running.
There is a malfunction if:
R the 0075 SRS warning lamp does not light
up when the ignition is switched on
R the engine is running and the 0075SRS
warning lamp does not go out after a few
seconds
R the engine is running and the 0075SRS
warning lamp lights up again Triggering of Emergency Tensioning
Devices and air bags During the first stage of a collision, the air bag
control unit evaluates important physical
data relating to vehicle deceleration or accel-
eration, such as:
R duration
R direction
R magnitude
Based on the evaluation of this data, the air
bag control unit pre-emptively triggers the
Emergency Tensioning Device in the first
stage.
If there is an even higher rate of vehicle decel- eration or acceleration in a longitudinal direc-tion, the front air bags are also deployed.
Your vehicle has adaptive, two-stage front air bags. The air bag control unit evaluates vehi-cle deceleration or acceleration in the event
of a collision. In the first deployment stage,
the front air bag is filled with enough propel-
lant gas to reduce the risk of injuries. The
front air bag is fully deployed if a second
deployment threshold is reached within a few
milliseconds.
The Emergency Tensioning Device and air bag triggering thresholds are variable and are
adapted to the detected rate of deceleration
or acceleration of the vehicle. This process is
pre-emptive in nature. The triggering process must take place in good time at the start of
the collision.
The rate of vehicle deceleration or accelera-
tion and the direction of the force are essen-
tially determined by:
R the distribution of forces during the colli-
sion
R the collision angle
R the deformation characteristics of the vehi-
cle
R the characteristics of the object with which
the vehicle has collided
Factors that can only be seen and measured
after a collision has occurred do not play a Occupant safety
41Safety Z

decisive role in the deployment of an air bag,
nor do they provide an indication of air bag
deployment.
The vehicle may be deformed significantly,
e.g. the hood or the fender, without an air bag
being deployed. This is the case if only parts
which are relatively easily deformed are affec- ted and the rate of deceleration is not high.
Conversely, air bags may be deployed even
though the vehicle suffers only minor defor-
mation. This is the case if, for example, very
rigid vehicle parts such as longitudinal body
members are hit, and sufficient deceleration
occurs as a result.
i The front Emergency Tensioning Devices
can only be triggered if the seat belt
tongues on the front seats are correctly
engaged in the seat belt buckles.
i Not all air bags are deployed in an acci-
dent. The different air bag systems work
independently of each other.
How the air bag system works is deter-
mined by predicting the severity of the acci-
dent, especially vehicle deceleration or
acceleration, and the type of accident:
R head-on collision
R side impact
R rollover
Safety guidelines for seat belts, Emer-
gency Tensioning Devices (ETDs) and
air bags G
WARNING
R Damaged seat belts or seat belts that have
been subjected to stress in an accident
must be replaced. Their anchoring points
must also be checked. Only use seat belts
installed or supplied by an authorized
Mercedes-Benz Center.
R Air bags and pyrotechnic Emergency Ten-
sioning Devices (ETDs) contain perchlorate material, which may require special han-
dling and regard for the environment.
Check your national disposal guidelines. In California, see
www.dtsc.ca.gov/
HazardousWaste/Perchlorate/
index.cfm.
R Air bags and ETDs are designed to function
on a one-time-only basis. An air bag or ETD
that has deployed must be replaced.
R Do not pass seat belts over sharp edges.
They could tear.
R Do not make any modification that could
change the effectiveness of the seat belts.
R Do not bleach or dye seat belts, as this may
severely weaken them. In a crash, they may
not be able to provide adequate protection.
R Do not make any modifications to the SRS
wiring or components.
R Do not modify or remove any components
or parts of the SRS.
R Do not install additional trim material, seat
covers, badges, etc. to the:
- padded steering wheel boss
- knee bag covers
- front-passenger air bag cover
- outer side of front seat bolsters
- outer seat bolsters of the rear bench seat
backrest
- roof frame trim
R Do not install additional electrical/elec-
tronic equipment on or near SRS compo-
nents and wiring.
R Keep the area between the air bags and
occupants free of objects (e.g. packages,
handbags, umbrellas etc.).
R Do not hang any objects such as coat hang-
ers on the coat hooks or the grab handle
above the door. These items may be thrownaround in the vehicle and cause head and
other injuries when the window curtain air
bag is deployed.
R Air bag system components will be hot after
an air bag has inflated. Do not touch them.
R Never rest your feet on the dashboard or
the seat. Always keep both feet on the floor in front of the seat. 42
Occupant safetySafety

R
Improper repair work on the SRS creates a
risk of rendering the SRS inoperative or
causing unintended air bag deployment.
Work on the SRS must therefore only be
performed by qualified technicians. Con-
sult an authorized Mercedes-Benz Center.
R For your protection and the protection of
others, when scrapping the air bag unit or
ETD, our safety instructions must be fol-
lowed. These are available from any author-
ized Mercedes-Benz Center.
R Given the considerable deployment speed,
required inflation volume, and the material
of the air bags, there is the possibility of
abrasions or other, potentially more serious injuries resulting from air bag deployment.
If you sell your vehicle, Mercedes-Benz
strongly recommends that you inform the
subsequent owner that the vehicle is equip-
ped with SRS. Also, refer them to the appli-
cable section in the Operator's Manual. Air bags
Important safety notes G
WARNING
The air bag parts are hot after the airbag has
been deployed. There is a risk of injury.
Do not touch the air bag parts. Have the
deployed air bags replaced at a qualified spe- cialist workshop as soon as possible. G
WARNING
Air bags are designed to reduce the potential of injury and fatality in certain:
R frontal impacts (driver's/front-passenger
air bags and knee bags)
R side impacts (side impact air bags and win-
dow curtain air bags)
R rollover (window curtain air bags)
However, no system available today can com-
pletely eliminate injuries and fatalities. When the air bags are deployed, a small
amount of powder temporarily comes out of
the air bags. This dust, however, is generally
neither harmful to your health, nor does it
indicate a fire in the vehicle. In order to pre-
vent potential breathing difficulties, you may
wish to get out of the vehicle as soon as it is
safe to do so. If you have any breathing diffi-
culty but cannot get out of the vehicle after
the air bag inflates, then get fresh air by open-
ing a window or door. G
WARNING
In order to reduce the potential danger of
injuries caused during the deployment of the
front air bags, the driver and front passenger
must always be correctly seated and wear
their seat belts.
For maximum protection in the event of a col- lision, you must always be in the normal seat
position with your back against the backrest.
Fasten your seat belt and make sure that it is
correctly positioned on your body.
As the air bag inflates with considerable
speed and force, a proper seating position
and correct positioning of the hands on the
steering wheel will help to keep you at a safe distance from the air bag. Occupants who are
not wearing their seat belt, are not seated
properly or are too close to the air bag can be seriously injured or killed by an air bag, as it
inflates with great force instantaneously:
R sit with the seat belt fastened correctly and
in a position that is as upright as possible
with your back against the backrest.
R move the driver's seat as far back as pos-
sible, still permitting proper operation of
vehicle controls. The distance from the cen- ter of the driver's chest to the center of the
air bag cover on the steering wheel must be
at least 10 inches (25 cm). You should be
able to accomplish this by adjusting the
seat and steering wheel. If you have any
difficulties, please contact an authorized
Mercedes-Benz Center. Occupant safety
43Safety
Z

R
do not lean your head or chest close to the
steering wheel or dashboard.
R only hold the steering wheel on the outside.
Placing hands and arms inside the rim can
increase the risk and potential severity of
hand/arm injury if the driver front air bag
inflates.
R adjust the front-passenger seat as far back
as possible from the dashboard when the
seat is occupied.
R occupants, especially children, should
never place their bodies or lean their heads
in the area of the door where the side
impact air bag inflates. This could result in
serious or fatal injuries should the side
impact air bag be deployed. Always sit as
upright as possible, wear the seat belt prop-
erly and use an appropriately sized infant
restraint, toddler restraint or booster seat
recommended for the size and weight of the
child.
Failure to follow these instructions can result in severe injuries to you or other occupants.
If you sell your vehicle, it is important that you
make the buyer aware of this safety informa-
tion. Be sure to give the buyer this Operator's
Manual.
If the air bags are deployed, you will hear a
bang, and a small amount of powder may also
be released. Only in rare cases will the bang
affect your hearing. The powder that is
released generally does not constitute a
health hazard and does not indicate that there is a fire in the vehicle. The dust might cause
some temporary breathing difficulty for peo-
ple with asthma or other breathing trouble. To avoid this, you may wish to get out of the
vehicle as soon as it is safe to do so. You can
also open the window to allow fresh air to
enter the vehicle interior. The 0075SRS warn-
ing lamp lights up.
The air bag installation locations are identi-
fied by the AIR BAG symbol.
The air bags are deployed if the air bag control
unit detects the need for deployment. Only in the event of such a situation will the air bags
provide their supplemental protection.
If the driver and front passenger do not wear their seat belts, it is not possible for the air
bags to provide their supplemental protec-
tion.
In the event of other types of impacts and
impacts below air bag deployment thresh-
olds, the air bags will not deploy. The driver
and passenger will then be protected to the
extent possible by a properly fastened seat
belt. A properly fastened seat belt is also nee- ded to provide the best possible protection in
a rollover.
Air bags provide additional protection; they
are not, however, a substitute for seat belts.
All vehicle occupants must fasten their seat
belts regardless of whether your vehicle is
equipped with air bags or not.
It is important for your safety and that of your
passenger to have deployed air bags replaced 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.
i After an air bag has been deployed, have
the vehicle towed to the nearest qualified
specialist workshop, even if your vehicle is
ready to drive.
Front air bags Driver's air bag
0043deploys in front of the
steering wheel; front-passenger front air 44
Occupant safetySafety

bag
0044deploys in front of and above the glove
box.
The front air bags increase protection for the driver's and front passenger's head and
chest.
They are deployed:
R at the start of an accident with a high rate of
vehicle acceleration or deceleration in a
longitudinal direction
R if the system determines that air bag
deployment can offer additional protection
to that provided by the seat belt
R independently of other air bags in the vehi-
cle
The release time of the front air bags is
dependent upon the use of the seat belt.
If the vehicle rolls over, the front air bags are
generally not deployed.
Your vehicle has adaptive, two-stage front air bags. The air bag control unit evaluates vehi-cle deceleration or acceleration in the event
of a collision. In the first deployment stage,
the front air bag is filled with part of the total
available propellant gas, thereby reducing the
risk of injury. If the air bag control unit rec-
ognizes within a few milliseconds that the
vehicle is being braked or accelerated faster
than originally predicted, the front air bag is
filled with the maximum amount of propellant gas available.
The deployment of the front-passenger front
air bag is also influenced by the weight cate-
gory of the front passenger, which is deter-
mined by the Occupant Classification System
(OCS) (Y page 47).
The lighter the passenger-side occupant, the
higher the vehicle deceleration rate required
(predicted at the start of the impact) for sec- ond stage inflation of the front-passenger
front air bag. In the second stage, the front air
bags are inflated with the maximum amount
of propellant gas available. The front-passenger front air bag will only
deploy if:
R the system, based on the OCS weight sen-
sor readings, detects that the front-
passenger seat is occupied
R the PASSENGER air bag OFF indicator lamp
on the center console is not lit
(Y page 47)
R the air bag control unit predicts a high
impact severity
The front air bags are not deployed in situa-
tions where a low impact severity is predic-
ted. You will then be protected by the fas-
tened seat belt.
Knee bags Driver's knee bag
0043deploys underneath the
steering column and front-passenger knee
bag 0044underneath the glove box. They
deploy together with the front air bags. They
are designed to operate together with the
front air bags in frontal impacts if certain
thresholds are exceeded. The knee bags
operate at best in conjunction with correctly
positioned and fastened seat belts.
Knee bags provide increased protection for
the driver and front passenger against the risk
of:
R knee injuries
R thigh injuries
R lower leg injuries Occupant safety
45Safety Z

Side impact air bags
G
WARNING
Using unsuitable seat covers could restrict or even prevent deployment of the air bags inte- grated into the seats. Consequently, the air
bags cannot protect vehicle occupants as
they are designed to do. In addition, the func-
tion of the air bag deactivation system could
be restricted. 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. G
WARNING
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
any more. 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.
You should only use seat covers that have
been approved for your vehicle by Mercedes-
Benz. The seat covers must have a special
tear seam for side impact air bags. Otherwise, the side impact air bags cannot deploy cor-
rectly and therefore cannot provide the inten-
ded protection in the event of an accident. Front side impact air bags
0043and rear side
impact air bags 0044deploy next to the outer
seat cushions.
When deployed, the side impact air bags offer additional protection of the thorax for occu-
pants on the front seats as well as also of the
pelvis for the vehicle occupants on the side of the vehicle on which the impact occurs. How-ever, they do not protect the:
R head
R neck
R arms
The side impact air bags are deployed:
R on the side on which an impact occurs
R at the start of an accident with a high rate of
lateral vehicle deceleration or acceleration,
e.g. in a side impact
R independently of the use of the seat belt
R independently of the Emergency Tension-
ing Devices
R independently of the front air bags
If the vehicle rolls over, the side impact air
bags are generally not deployed. Side impact air bags are deployed if the system detects
high vehicle deceleration or acceleration in a
lateral direction and determines that side
impact air bag deployment can offer addi-
tional protection to that provided by the seat
belt.
Side impact air bags will not deploy in side
impacts which do not exceed the system's
preset deployment thresholds for lateral
acceleration/deceleration. You will then be
protected by the fastened seat belt. 46
Occupant safetySafety

The side impact air bag on the front-
passenger side will deploy if the front-
passenger seat belt is fastened, regardless of whether the front-passenger seat is occupied
or not.
The side impact air bag on the front-
passenger side does not deploy under the fol-
lowing conditions:
R OCS has detected that the front-passenger
seat is unoccupied.
R the front-passenger seat belt is not fas-
tened.
Window curtain air bags Window curtain air bags
0043enhance the level
of protection for the head, but not chest or
arms, of the vehicle occupants on the side of the vehicle on which the impact occurs.
Window curtain air bags 0043are integrated
into the side of the roof frame and deployed in the area from the A-pillar to the C-pillar.
Window curtain air bags are deployed:
R at the start of an accident with a high rate of
lateral vehicle deceleration or acceleration,
e.g. in a side impact
R on the side on which an impact occurs
R on the driver's side and passenger side, in
the event of a vehicle rollover and if the
system determines that air bag deployment
can offer the vehicle occupants additional
protection to that provided by the seat belt
R independently of the use of the seat belt R
regardless of whether the front-passenger
seat is occupied
R independently of the front air bags
Window curtain air bags 0043will not deploy in
the event of impacts which do not exceed the
system's preset deployment thresholds for
vehicle acceleration/deceleration. You will
then be protected by the fastened seat belt. Occupant Classification System
(OCS)
How the Occupant Classification Sys-
tem works G
WARNING
If the 00730074 indicator lamp illuminates
when an adult or someone larger than a small individual is in the front-passenger seat, havethe front passenger reposition himself or her-
self in the seat until the 00730074indicator
lamp goes out.
In the event of a collision, the air bag control
unit will not allow front-passenger front air
bag deployment when the OCS has classified
the front-passenger seat occupant as weigh-
ing as much as or less than a typical 12-
month-old child in a standard child restraint or if the front-passenger seat is classified as
being empty.
When the OCS senses that the front-
passenger seat occupant is classified as
being up to or less than the weight of a typical
12-month-old child in a standard child
restraint, the 00730074indicator lamp will
illuminate when the engine is started and
remain illuminated, indicating that the front-
passenger front air bag is deactivated.
When the OCS senses that the front-
passenger seat is classified as being empty,
the 00730074 indicator lamp will illuminate
when the engine is started and remain illumi-
nated, indicating that the front-passenger
front air bag is deactivated.
When the OCS senses that the front-
passenger seat occupant is classified as Occupant safety
47Safety
Z

being heavier than the weight of a typical 12-
month-old child seated in a standard child
restraint or as being a small individual (such
as a young teenager or a small adult), the
00730074 indicator lamp will illuminate for
approximately 6 seconds when the engine is
started and then, depending on occupant
weight sensor readings from the front-
passenger seat, remain illuminated or go out. With the 00730074 indicator lamp illumina-
ted, the front-passenger front air bag is deac-
tivated. With the 00730074indicator lamp
out, the front-passenger front air bag is acti-
vated.
When the OCS senses that the front-
passenger seat occupant is classified as an
adult or someone larger than a small individ-
ual, the 00730074 indicator lamp will illumi-
nate for approximately 6 seconds when the
engine is started and then go out, indicating
that the front-passenger front air bag is acti-
vated.
If the 00730074 indicator lamp is illuminated,
the front-passenger front air bag is deactiva-
ted and will not be deployed.
If the 00730074 indicator lamp is not illumi-
nated, the front-passenger front air bag is
activated and will be deployed:
R in the event of certain frontal impacts
R if impact exceeds a preset deployment
threshold
R independently of the side impact air bags
If the front-passenger front air bag is
deployed, the rate of inflation will be influ-
enced by:
R the rate of relevant vehicle deceleration as
assessed by the air bag control unit
R the front passenger's weight category as
identified by OCS G
WARNING
According to accident statistics, children are
safer when properly restrained on the rear
seats than on the front-passenger seat. Thus, we strongly recommend that children be placed in the rear seats whenever possible.
Regardless of seating position, children 12
years old and under must be seated and prop- erly secured in an appropriate infant restraint,
toddler restraint, or booster seat recommen-
ded for the size and weight of the child.
The infant or child restraint must be properly
secured with the vehicle's seat belt, the seat
belt and Top Tether strap, or lower anchors
and Top Tether strap, fully in accordance with the child seat manufacturer's instructions.
Occupants, especially children, should always
sit as upright as possible, wear the seat belt
properly and use an appropriately sized infant
restraint, toddler restraint, or booster seat
recommended for the size and weight of the
child.
Children can be killed or seriously injured by
an inflating air bag. Note the following impor-
tant information when circumstances require you to place a child in the front-passenger
seat:
R Your vehicle is equipped with air bag tech-
nology designed to deactivate the front-
passenger front air bag in your vehicle
when the system senses the weight of a
typical 12-month-old child or less along
with the weight of a standard appropriate
child restraint on the front-passenger seat.
R A child in a rear-facing child restraint on the
front-passenger seat will be seriously
injured or even killed if the front-passenger
front air bag inflates in a collision which
could occur under some circumstances,
even with the air bag technology installed in your vehicle. The only means to eliminate
this risk completely is never to place a child
in a rear-facing child restraint in the front-
passenger seat. We therefore strongly rec- ommend that you always place a child in a
rear-facing child restraint on the rear seat.
R If you install a rear-facing child restraint on
the front-passenger seat, make sure the
00730074 indicator lamp is illuminated,
indicating that the front-passenger front air bag is deactivated. Should the 0073007448
Occupant safetySafety