2017 MERCEDES-BENZ CLA length

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

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

Applying automatically The electric parking brak e is automatically
applie d when th e transmission is in position P
and : R
th e engin e is switched off orR
th e driver is no t wearing a seat belt and th e
driver's door is opened
To preven t th e electric parking brak e from bein g
automatically applied, pull handle C .
The electric parking brak e is also engage d auto -
matically if: R
Distanc e Pilo t DISTRONI C bring s th e vehicl e
to a standstill orR
th e HOLD function is keepin g th e vehicl e sta-
tionary R
Parking Pilo t is keepin g th e vehicl e stationary
In addition , at least on e of th e followin g condi-
tion s mus t be fulfilled :R
th e engin e is switched offR
th e driver is no t wearing a seat belt and th e
driver's door is opened R
there is a system malfunctionR
th e powe r supply is insufficien tR
th e vehicl e is stationary for a lengthy period
The red I (US A only) or $ (Canada only)
indicator lamp in th e instrumen t cluste r goe s
out .
The electric parking brak e is no t automatically
engage d if th e engin e is switched off by th e ECO
start/sto p function .
Releasing automatically Your vehicle's electric parking brak e is auto -
matically release d if all of th e followin g condi-
tion s are met :R
th e engin e is running.R
th e transmission is in position D or R .R
th e seat belt has been fastened.R
you depress th e accelerato r pedal .
If th e transmission is in position R , th e trunk lid
mus t be closed. If your seat belt is no t fastened, th e followin g
condition s mus t be fulfilled to automatically
release th e electric parking brake: R
th e driver's door is closed. R
you hav e shifte d out of transmission position
P or you hav e previously driven faste r than
2 mph (3 km/h).
Ensur e that you do no t depress th e accelerato r
pedal unintentionally. Otherwise th e parking
brak e will be release d and th e vehicl e will start
to move.
Eme rg ency brakingThe vehicl e can also be braked during an emer-
gency by usin g th e electric parking brake. X
Whil e driving, push handle C of th e electric
parking brak e ( Y
page 141).
The vehicl e is braked as lon g as you keep
handle C of th e electric parking brak e
pressed. The longer th e electric parking brak e
handle C is depressed, th e greate r th e brak -
ing force .
During braking : R
a warning tone sounds R
th e Releas e Parkin g Brake message
appear s R
th e red I (US A only) or $ (Canada
only) indicator lamp in th e instrumen t cluste r
flashes
When th e vehicl e has been braked to a stand -
still, th e electric parking brak e is engaged.
Pa rk ing the vehicle for a long period If you leav e th e vehicl e parked for longer than
four weeks, th e battery may be damaged by
exhaustive discharging.
If you leav e th e vehicl e parked for longer than six
weeks, th e vehicl e may suffer damag e as a
result of lack of use. X
Visit a qualified specialist workshop and see k
advice .
i You can obtain information about trickle
chargers from a qualified specialist work-
shop.142
Parking
Driving and parking

R
that are parallel to the direction of travel and
at least 39.5 in (1.0 m) longer than your vehi-
cle R
that are at right angles to the direction of
travel and at least 39.5 in (1.0 m) wider than
your vehicle
i Note that Parking Pilot cannot measure the
length of a parking space if it is at right angles
to the direction of travel. You will need to
judge whether your vehicle will fit into the
parking space.
When driving at speeds below 19 mph
(30 km/h), you will see parking symbol D as a
status indicator in the instrument cluster. When
a parking space has been detected, an arrow
towards the right or the left also appears. Park-
ing Pilot only displays parking spaces on the
front-passenger side as standard. Parking
spaces on the driver's side are displayed as
soon as the turn signal on the driver's side is
activated. When parking on the driver's side,
this must remain activated until you confirm the
use of Parking Pilot by pressing the v button
on the multifunction steering wheel. The system
automatically determines whether the parking
space is parallel or at right-angles to the direc-
tion of travel.
A parking space is displayed while you are driv-
ing past it, and until you are approximately 50 ft
(15 m) away from it.
Parking
G WARNING
If you leave the vehicle when it is only being
braked by Parking Pilot, it could roll away if: R
there is a malfunction in the system or in
the voltage supply. R
the electrical system in the engine com-
partment, the battery or the fuses are tam-
pered with. R
the battery is disconnected. R
the vehicle is accelerated, e.g. by a vehicle
occupant.
There is a risk of an accident.
Before leaving the vehicle, always secure it
against rolling away.
i If Parking Assist PARKTRONIC detects
obstacles, Parking Pilot brakes automatically whilst the vehicle is parking. You are respon-
sible for braking in good time. X
Stop the vehicle when the parking space sym-
bol shows the desired parking space in the
instrument cluster. X
Shift the transmission to position R .
The Start Parking Pilot? Yes: OK No:
8 message appears in the multifunction
display. X
To cancel the procedure: press the 8
button on the multifunction steering wheel or
pull away.
or X
To park using Parking Pilot: press the v
button on the multifunction steering wheel.
The Parking Pilot Active Accelerate
and Brake Observe Surroundings mes-
sage appears in the multifunction display. X
Let go of the multifunction steering wheel. X
Back up the vehicle, being ready to brake at all
times. When backing up, drive at a speed
below approximately 6 mph (10 km/h). Oth-
erwise Parking Pilot is canceled.
Parking Pilot brakes the vehicle to a standstill
when the vehicle approaches the rear border
of the parking space.
Maneuvering may be required in tight parking
spaces.
The Parking Pilot Active Select D
Observe Surroundings message appears in
the multifunction display. X
Shift the transmission to position D while the
vehicle is stationary.
Parking Pilot immediately steers in the other
direction.
The Parking Pilot Active Accelerate
and Brake Observe Surroundings mes-
sage appears in the multifunction display.
i You will achieve the best results by waiting
for the steering procedure to complete before
pulling away. X
Drive forwards and be ready to brake at all
times.
Parking Pilot brakes the vehicle to a standstill
when the vehicle approaches the front border
of the parking space.
Maneuvering may be required in tight parking
spaces.
The Parking Pilot Active Select R
Observe Surroundings message appears in
the multifunction display.164
Driving systems
Driving and parking

(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 the time has been set incorrectly R
in active driving situations, such as when you
change lanes or change your speed
ATTENTION ASSIST is reset when you continue
your journey and starts assessing your tiredness
again 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 182) of
the on-board computer. X
Select the Assistance display for Attention
Assist using the on-board computer
( Y
page 182).
The following information is displayed: R
Length of the journey since the last break. R
The Attention Level determined by ATTEN-
TION ASSIST, 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 output a warn-
ing, the System Passive message appears.
The bar display then changes the display,
such as when 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 183).
The system determines the attention level of
the driver depending on the setting selected:
Standard selected: the sensitivity with which
the system determines the attention level is set
to normal.
Sensitive selected: the sensitivity is set
higher. The attention level detected by Attention
Assist is adapted accordingly and the driver is
warned earlier.
When ATTENTION ASSIST is deactivated, the

the household rubbish. They
must be collected separately
and recycled to protect the
environment.
Dispose of batteries in an
environmentally friendly
manner. Take discharged
batteries to a qualified spe-
cialist workshop or a special
collection point for used bat-
teries.
! Have the battery checked regularly at a
qualified specialist workshop.
Observe the service intervals in the Mainte-
nance Booklet or contact a qualified specialist
workshop for more information.
! You should have all work involving the bat-
tery carried out at a qualified specialist work-
shop. In the exceptional case that it is neces-
sary for you to disconnect the battery your-
self, make sure that: R
you switch off the engine and remove the
key. On vehicles with KEYLESS-GO, ensure
that the ignition is switched off. Check that
all the indicator lamps in the instrument
cluster are off. Otherwise, electronic com-
ponents, such as the alternator, may be
damaged. R
you first remove the negative terminal
clamp and then the positive terminal
clamp. Never swap the terminal clamps.
Otherwise, the vehicle's electronic system
may be damaged. R
in vehicles with automatic transmission,
the transmission is locked in position P
after disconnecting the battery. The vehicle
is s ecured against rolling away. You can
th
en no longer move the vehicle.
The battery and the cover of the positive ter-
minal clamp must be installed securely during
operation.
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.
Battery acid is caustic. Avoid contact
with skin, eyes or clothing.
Wear suitable protective clothing,
especially gloves, apron and face-
guard.
Rinse any acid spills immediately
with clear water. Contact 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.
Like other batteries, the vehicle battery may
discharge 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.
Only replace a battery with a battery that has
been recommended by Mercedes-Be nz.272
Battery (vehicle)
Breakdown assistance

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 ven-
tilation while charging and jump-starting. Do not lean over a battery.
G WARNING
During the charging process, a battery produces hydrogen gas. If a short circuit occurs or sparks
are created, the hydrogen gas can ignite. There is a risk of an explosion. R
Make sure that the positive terminal of a connected battery does not come into contact with
vehicle parts. R
Never place metal objects or tools on a battery. R
It is important that you observe the described order of the battery terminals when connecting
and disconnecting a battery. R
When jump-starting, make sure that the battery poles with identical polarity are connected. R
It is particularly important to observe the described order when connecting and disconnecting
the jumper cables. R
Never connect or disconnect the battery terminals while the engine is running.
G WARNING
A discharged battery can freeze at temperatures below freezing point. When jump-starting 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.
! Avoid repeated and lengthy starting attempts. Otherwise, the catalytic converter could be
damaged by the non-combusted fuel.
If the indicator/warning lamps do not light up in the instrument cluster at low temperatures, it is very
likely that the discharged battery has frozen. In this case you may neither jump-start the vehicle nor
charge the battery. Let the battery thaw first. The service life of a thawed-out battery may be shorter.
The starting characteristics can be impaired, particularly at low temperatures. Have the thawed-out
battery checked at a qualified specialist workshop.
Do not start the vehicle using a rapid charging device. If your vehicle's battery is discharged, the
engine can be jump-started from another vehicle or from a second battery using jumper cables.
Observe the following points: R
The battery is not accessible in all vehicles. If the other vehicle's battery is not accessible, jump-
start the vehicle using a second battery or a jump-starting device. R
You may only jump-start the vehicle when the engine and exhaust system are cold. R
Do not start the engine if the battery is frozen. Let the battery thaw first. R
Only jump-start from batteries with a 12 V voltage rating. R
Only use jumper cables that are not damaged and have a sufficient cross-section and insulated
terminal clamps. R
Make sure that the two vehicles do not touch.274
Jump-starting
Breakdown assistance