2017 MERCEDES-BENZ CLA warning lights

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 OFF indicator
lamp is off, the front-passenger front air bag
may deploy in the event of an accident. The
child could be struck by the air bag. This poses
an increased risk of injury or even fatal injury.
Make sure that the front-passenger front air
bag has been disabled. The PASSENGER AIR
BAG OFF indicator lamp must be lit.
If the PASSENGER AIR BAG OFF indicator lamp
stays off, do not install a rearward-facing child
restraint system on the front-passenger seat.
You can find more information on OCS under
"Problems with the Occupant Classification Sys-
tem" ( Y
page 50).
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 OFF indicator lamp is off
This poses an increased risk of injury or even
fatal injury.
Always move the front-passenger seat as far
back as possible and fully retract the seat
cushion length. Always make sure that the
shoulder belt strap is correctly routed from
the vehicle belt sash guide to the shoulder belt guide on the child restraint system. The
shoulder belt strap must be routed forwards
and downwards from the vehicle belt sash
guide. If necessary, adjust the vehicle belt
sash guide and the front-passenger seat
accordingly. Always observe the child
restraint system manufacturer's installation
instructions.
If OCS determines that: R
the front-passenger seat is unoccupied, the
PASSENGER AIR BAG OFF indicator lamp
lights up after the system self-test and
remains lit. This indicates that the front-
passenger front air bag is deactivated. R
the front-passenger seat is occupied by a
child of up to twelve months old, in a standard
child restraint system, the PASSENGER AIR
BAG OFF indicator lamp lights up after the
system self-test and remains lit. This indi-
cates that the front-passenger front air bag is
deactivated.
But even in the case of a twelve-month-old
child, in a standard child restraint system, the
PASSENGER AIR BAG OFF indicator lamp can
go out after the system self-test. This indi-
cates that the front-passenger front air bag is
activated. The result of the classification is
dependent on, among other factors, the child
restraint system and the child's stature. It is
recommended that you install the child
restraint system on a suitable rear seat. R
the front-passenger seat is occupied by a per-
son of smaller stature (e.g. a teenager or
small adult), the PASSENGER AIR BAG OFF
indicator lamp lights up and remains lit after
the system self-test depending on the result
of the classification or, alternatively, goes out. -
If the PASSENGER AIR BAG OFF indicator
lamp is off, move the front-passenger seat
as far back as possible. Alternatively, a per-
son of smaller stature can sit on a rear seat. -
If the PASSENGER AIR BAG OFF indicator
lamp is lit, a person of smaller stature
should not use the front-passenger seat. R
the front-passenger seat is occupied by an
adult or a person of adult stat ure, the
PASSENGER AIR BAG OFF indicator lamp
goes out after the system self-test. This indi-
cates that the front-passenger front air bag is
activated.48
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

Drivin g safet y systems
Overview of drivin g safet y systemsIn this section , you will fin d information about
th e followin g drivin g safet y systems :R
AB S ( A n ti-loc k B rakin g S ystem)
( Y
page 60)R
BA S ( B rak e A ssist S ystem) ( Y
page 60)R
Active Brak e Assis t ( Y
page 61 )R
ES P ®
( E lectronic S t ability P r ogram)
( Y
page 63)R
EB D ( E lectroni c B rak e forc e D istribution )
( Y
page 66 )R
ADAPTIV E BRAKE ( Y
page 66 )R
STEE R CONTROL ( Y
page 66)
Important safet y notesIf you fail to adapt your drivin g style or if you are
inattentive , th e drivin g safet y systems can nei-
ther reduce th e ris k of an acciden t no r override
th e laws of physics. Driving safet y systems are
merely aids designed to assist driving. You are
responsible fo r maintainin g th e distanc e to th e
vehicle in front, fo r vehicle speed, fo r braking in
goo d time, and fo r stayin g in lane. Always adapt
your drivin g style to suit th e prevailin g road and
weather condition s and maintain a saf e distanc e
from th e vehicle in front. Drive carefully.
The drivin g safet y systems described only wor k
as effectively as possible when there is ade-
quat e contact between th e tires and th e road
surface. Please pay special attention to th e
note s on tires , recommended minimum tire
tread depths, etc. ( Y
page 282).
In wintr y drivin g conditions, always use winte r
tires (M+ S tires )a nd if necessary, snow chains.
Only in this way will the driving safety systems
described in this section work as effectively as
possible.
ABS (Anti-lock Braking System)
General information
ABS regulates brake pressure in such a way that
the wheels do not lock when you brake. This
allows you to continue steering the vehicle when
braking. The % ABS warning lamp in the instrument
cluster lights up when the ignition is switched
on. It goes out when the engine is running.
ABS works from a speed of about 5 mph
(8 km/h), regardless of road-surface conditions.
ABS works on slippery surfaces, even when you
only brake gently.
Important safety notes
i Observe the "Important safety notes" sec-
tion ( Y
page 60).
G WARNING
If ABS is faulty, the wheels could lock when
braking. The steerability and braking charac-
teristics may be severely impaired. Addition-
ally, further driving safety systems are deac-
tivated. There is an increased danger of skid-
ding and accidents.
Drive on carefully. Have ABS checked imme-
diately at a qualified specialist workshop.
When ABS is malfunctioning, other systems,
including driving safety systems, will also
become inoperative. Observe the information
on the ABS warning lamp ( Y
page 218) and dis-
play messages which may be shown in the
instrument cluster ( Y
page 189).
Braking X
If ABS intervenes: continue to depress the
brake pedal vigorously until the braking sit-
uation is over. X
To make a full brake application: depress
the brake pedal with full force.
If ABS intervenes when braking, you will feel a
pulsing in the brake pedal.
The pulsating brake pedal can be an indication
of hazardous road conditions, and functions as a
reminder to take extra care while driving.
BAS (Brake Assist System)
General information
BAS operates in emergency braking situations.
If you depress the brake pedal quickly, BAS
automatically boosts the braking force, thus
shortening the stopping distance.60
Driving safety systems
Safety

R
Traction control is still activated. R
STEER CONTROL is no longer active R
ESP ®
still provides support when you brake
firmly.
Deactivating/activating ESP ®
(Mercedes ‑ AMG vehicles)Important safety notes
i Observe the "Important safety notes" sec-
tion ( Y
page 60).
You can select between the following states of
ESP ®
: R
ESP ®
is activated.R
SPORT handling mode is activated. R
ESP ®
is deactivated.
G WARNING
When SPORT handling mode is activated,
there is a greater risk of skidding and acci-
dents.
Only activate SPORT handling mode in the sit-
uations described in the following.
G WARNING
If you deactivate ESP ®
, ESP ®
no longer sta-
bilizes the vehicle. There is an increased risk
of skidding and an accident.
Only deactivate ESP ®
in the situations descri-
bed in the following.
In the following situations, it may be better to
activate SPORT handling mode or deactivate
ESP ®
: R
when using snow chains R
in deep snow R
on sand or gravel R
on specially designated roads when the vehi-
cle's own oversteering and understeering
characteristics are desired
Driving in SPORT handling mode or without
ESP ®
requires an extremely qualified and expe-
rienced driver.
i Activate ESP ®
as soon as the situations
described above no longer apply. ESP ®
will
otherwise not be able to stabilize the vehicle if the vehicle starts to skid or a wheel starts to
spin.
! Avoid spinning the driven wheels for an
extended period with ESP ®
deactivated. You
could otherwise damage the drivetrain.
Deactivating/activating ESP ®
X
To activate SPORT handling mode: briefly
press button C .
The t SPORT handling mode warning
lamp in the instrument cluster lights up. The
SPORT handling mode
message appears in
the multifunction display. X
To deactivate SPORT handling mode:
briefly press button C .
The t SPORT handling mode warning
lamp in the instrument cluster goes out. X
To deactivate ESP ®
: press button C until
the

SmartKey battery
Important safety notes
G WARNING
Batteries contain toxic and corrosive substan-
ces. If batteries are swallowed, it can result in
severe health problems. There is a risk of fatal
injury.
Keep batteries out of the reach of children. If
a battery is swallowed, seek medical attention
immediately.
The SmartKey batteries contain perchlorate
material, which may require special handling
and regard for the environment. National guide-
lines must be observed during disposal. In Cal-
ifornia, see www.dtsc.ca.gov/
HazardousWaste/Perchlorate/index.cfm .
Mercedes-Benz recommends that you have the
battery replaced at a qualified specialist work-
shop.
Checking the battery
X
Press the 7 or 6 button.
The battery is working properly if battery
check lamp C lights up briefly.
The battery is discharged if battery check
lamp C does not light up briefly.X
Change the battery ( Y
page 72).
i If the SmartKey battery is checked within
the signal reception range of the vehicle,
pressing the 7 or 6 button:R
locks or R
unlocks the vehicle
i You can get a battery at any qualified spe-
cialist workshop. Replacing the battery You require a CR 2025 3 V cell battery. X
Take the mechanical key out of the SmartKey
( Y
page 71).
X
Press mechanical key D into the opening in
the SmartKey in the direction of the arrow
until battery tray cover C opens. When doing
so, do not hold cover C shut.X
Remove battery tray cover C .
X
Repeatedly tap the SmartKey against your
palm until battery

Mirrors
Rear-view mirror X
Anti-glare mode: flick anti-glare lever C for-
wards or back.
Exterior mirrors
Adjusting the exterior mirrors
G WARNING
You could lose control of your vehicle if you do
the following while driving: R
adjust the driver's seat, head restraint,
steering wheel or mirrors R
fasten the seat belt
There is a risk of an accident.
Adjust the driver's seat, head restraint, steer-
ing wheel and mirror and fasten your seat belt
before starting the engine.
G WARNING
The exterior mirror on the front-passenger
side reduces the size of the image. Visible
objects are actually closer than they appear.
This means that you could misjudge the dis-
tance from road users traveling behind, e.g.
when changing lane. There is a risk of an acci-
dent.
For this reason, always make sure of the
actual distance from the road users traveling
behind by glancing over your shoulder. X
Turn the SmartKey to position 1 or 2 in the
ignition lock ( Y
page 121). X
Exterior mirror on the front-passenger side:
press button D .
Exterior mirror on the driver's side: press but-
ton C .
The indicator lamp in the corresponding but-
ton lights up in red.
The indicator lamp goes out again after some
time. You can adjust the selected exterior
mirror using button

i If you activate the residual heat function at
high temperatures, only the ventilation will be
activated. The blower runs at medium speed.
i You cannot use the ventilation to cool the
vehicle interior to a temperature lower than
the outside temperature.
Activating/deactivating X
Turn the SmartKey to position 0 in the ignition
lock or remove it ( Y
page 121).X
Press the K button.
The indicator lamp in the K button lights
up or goes out.
The indicator lamp in the button indicates that
the respective function is activated.
i Residual heat is deactivated automatically: R
after approximately 30 minutes R
when the ignition is switched on R
if the battery voltage drops
Air vents
Important safety notes
G WARNING
Very hot or very cold air can flow from the air
vents. This could result in burns or frostbite in
the immediate vicinity of the air vents. There
is a risk of injury.
Make sure that all vehicle occupants always
maintain a sufficient distance to the air out-
lets. If necessary, redirect the airflow to
another area of the vehicle interior.
In order to ensure the direct flow of fresh air
through the air vents into the vehicle interior,
please observe the following notes: R
keep the air inlet between the windshield and
the hood free of blockages, such as ice, snow
or leaves. R
never cover the air vents or air intake grilles in
the vehicle interior.
i For optimal climate control in the vehicle,
open the air vents completely and set the
adjusters to the central position. Setting the air vents
C
Side window defroster vent D
Side air vent X
To open a side air vent: turn the adjuster in
side air vent D to the left. X
To close a side air vent: turn the adjuster in
side air vent D clockwise as far as it will go.
i The center and rear air vents are adjusted in
the same way. Air vents 119
Climate control Z