warning lights MERCEDES-BENZ CLA 2017 User Guide

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

operates independently of the ECO start/stop
automatic engine switch-off function.
Key positions with the Start/Stop button
C
Start/Stop buttonD
Ignition lock
As soon as the ignition is switched on, all the
indicator lamps in the instrument cluster light
up.
For further information on situations in which an
indicator lamp either fails to go out after the
engine is started or lights up while driving,
please refer to "Warning and indicator lamps in
the instrument cluster" ( Y
page 217).
If Start/Stop button C has not yet been
pressed, this corresponds to the SmartKey
being removed from the ignition. X
To switch on the power supply: press
Start/Stop button C once.
The power supply is switched on. You can now
activate the windshield wipers, for example.
The power supply is switched off again if: R
the driver's door is opened and R
you press Start/Stop button C twice when in
this position X
To switch on the ignition: press Start/Stop
button C twice.
The ignition is switched on.
If you press Start/Stop button C once when
in this position, the ignition is switched off
again.
Removing the Start/Stop button
You can remove the Start/Stop button from the
ignition lock and start the vehicle as normal
using the SmartKey.
You can only switch between Start/Stop button
mode and SmartKey operation when the vehicle
is stationary. You must also engage park position P .X
Remove Start/Stop button C from ignition
lock D .
You do not have to remove the Start/Stop but-
ton from the ignition lock when you leave the
vehicle. You should, however, always take the
SmartKey with you when leaving the vehicle. As
long as the SmartKey is in the vehicle: R
the vehicle can be started using the Start/
Stop button R
the electrically powered equipment can be
operated
Starting the engine
Important safety notes
G WARNING
If children are left unsupervised in the vehicle,
they could: R
open the doors, thus endangering other
people or road users. R
get out and disrupt traffic. R
operate the vehicle's equipment.
Additionally, children could set the vehicle in
motion if, for example, they: R
release the parking brake. R
shifting the automatic transmission out of
park position P R
Start the engine.
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 or animals unattended in the
vehicle. Always keep the SmartKey out of
reach of children.
G WARNING
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. Inhaling
these exhaust gases leads to poisoning. There
is a risk of fatal injury. Therefore never leave
the engine running in enclosed spaces with-
out sufficient ventilation.122
Driving
Driving and parking

the SmartKey from the ignition, the automatic
transmission shifts to P automatically.
With the Start/Stop button: if you then open
the driver's door or the front-passenger door,
the automatic transmission shifts to P automat-
ically.
If you want the automatic transmission to
remain in neutral N , e.g. when having the vehicle
cleaned in an automatic car wash with a towing
system: X
Vehicles with the Start-Stop button:
remove the Start-Stop button from the igni-
tion lock. X
Insert the SmartKey into the ignition lock. X
All vehicles: switch the ignition on.X
Depress the brake pedal and keep it
depressed. X
Shift to neutral N .X
Release the brake pedal. X
Release the electric parking brake. X
Switch off the ignition and leave the SmartKey
in the ignition lock.
Electric parking brake
General notes
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. The function of the electric parking brake is
dependent on the on-board voltage. If the on-
board voltage is low or there is a malfunction in
the system, it may not be possible to apply the
released parking brake. X
If this is the case, only park the vehicle on
level ground and secure it to prevent it rolling
away. X
Shift the automatic transmission to position
P .
It may not be possible to release an applied
parking brake if the on-board voltage is low or
there is a malfunction in the system. Contact a
qualified specialist workshop.
The electric parking brake performs a function
test at regular intervals while the engine is
switched off. The s ounds that can be heard while
th is is occurring are normal.
Applying or releasing manually
X
To engage: push handle C .
When the electric parking brake is applied,
the red I (USA only) or $ (Canada
only) indicator lamp lights up in the instru-
ment cluster.
The electric parking brake can also be applied
when the SmartKey is removed. X
To release: pull handle C .
The red I (USA only) or $ (Canada
only) indicator lamp in the instrument cluster
goes out.
The electric parking brake can only be
released: R
when the SmartKey is in position 1 or 2 in
the ignition lock ( Y
page 121) orR
if the ignition was switched on using the
Start/Stop button Parking 141
Driving an d parking Z

Limited braking performance on salt-
treated roads If you drive on salted roads, a layer of salt resi-
due may form on the brake discs and brake
pads. This can result in a significantly longer
braking distance. R
In order to prevent any salt build-up, apply the
brakes occasionally while paying attention to
the traffic conditions. R
Carefully depress the brake pedal and the
beginning and end of a journey. R
Maintain a greater distance to the vehicle
ahead.
Servicing the brakes
! The brake fluid level may be too low, if: R
if the red brake warning lamp lights up in
the instrument cluster and R
you hear a warning tone while the engine is
running
Observe additional warning messages in the
multifunction display.
The brake fluid level may be too low due to
brake pad wear or leaking brake lines.
Have the brake system checked immediately.
Consult a qualified specialist workshop to
arrange this.
! A function or performance test should only
be carried out on a 2-axle dynamometer. If
you wish to operate the vehicle on such a
dynamometer, please consult a qualified spe-
cialist workshop in advance. You could oth-
erwise damage the drive train or the brake
system.
! As the ESP ®
system operates automatically,
the engine and the ignition must be switched
off (the SmartKey must be in position 0 or 1 in
the ignition lock) if: R
the electric parking brake is tested on a
brake dynamometer (for a maximum of
ten seconds) R
the vehicle is towed with the front axle
raised.
Braking triggered automatically by ESP ®
may
seriously damage the brake system.
All checks and maintenance work on the brake
system must be carried out at a qualified spe-
cialist workshop. Have brake pads installed and brake fluid
replaced at a qualified specialist workshop.
If the brake system has only been subject to
moderate loads, you should test the functional-
ity of your brakes at regular in t ervals.
You can find a description of Brake Assist (BAS)
on ( Y
page 60).
Mercedes-Benz recommends that you only have
brake pads/linings installed on your vehicle
which have been approved for Mercedes-Benz
vehicles or which correspond to an equivalent
quality standard. Brake pads/linings which have
not been approved for Mercedes-Benz vehicles
or which are not of an equivalent quality could
affect your vehicle's operating safety.
Mercedes-Benz recommends that you only use
brake fluid that has been specially approved for
your vehicle by Mercedes-Benz, or which corre-
sponds to an equivalent quality standard. Brake
fluid which has not been approved for
Mercedes-Benz vehicles or which is not of an
equivalent quality could affect your vehicle's
operating safety.
Checking brake lining thickness You can measure the break pad/lining thick-
ness using a test gage. Color-coding (green or
red) on the test gage allows you to determine
whether the brake pad/lining thickness is still
sufficient. The test gage is in the vehicle docu-
ment wallet in the glove box.
Front wheel146
Driving tips
Driving and parking

i Parking Assist PARKTRONIC is automati-
cally activated when you turn the SmartKey to
position 2 in the ignition lock.
Problems with Parking Assist PARKTRONIC Problem
Possible causes/consequences and P Solutions
Only the red segments in
the Parking Assist
PARKTRONIC warning
displays are lit. You also
hear a warning tone for
approximately two sec-
onds.
Parking Assist
PARKTRONIC is then
deactivated and the indi-
cator lamp on the
PARKTRONIC button
lights up. Parking Assist PARKTRONIC has malfunctioned and has been deacti-
vated. X
If problems persist, have Parking Assist PARKTRONIC checked at a
qualified specialist workshop.
Only the red segments in
the Parking Assist
PARKTRONIC warning
displays are lit. Parking
Assist PARKTRONIC is
then deactivated. The Parking Assist PARKTRONIC sensors are dirty or there is inter-
ference. X
Clean the Parking Assist PARKTRONIC sensors ( Y
page 262).X
Switch the ignition back on.
The problem may be caused by an external source of radio or ultra-
sound waves. X
Check to see if Parking Assist PARKTRONIC works at a different
location.
Parking Pilot
General notes Parking Pilot is an electronic parking aid with
ultrasound. It measures the road on both sides
of the vehicle. A parking symbol indicates a suit-
able parking space. Active steering intervention
and brake application can assist you during
parking and when exiting a parking space. Park-
ing Assist PARKTRONIC is also available
( Y
page 160).
Important safety notes
Parking Pilot is only an aid. It is not a replace-
ment for your attention to your immediate sur-
roundings. You are always responsible for safe
maneuvering, parking and exiting a parking
space. Make sure that no persons, animals or
objects are in the maneuvering range. When Parking Assist PARKTRONIC is deactiva-
ted, Parking Pilot is also unavailable.
G WARNING
While parking or pulling out of a parking
space, the vehicle swings out and can drive
onto areas of the oncoming lane. This could
result in a collision with another road user.
There is a risk of an accident.
Pay attention to other road users. Stop the
vehicle if necessary or cancel the Parking Pilot
parking procedure.
! If unavoidable, you should drive over obsta-
cles such as curbs slowly and not at a sharp
angle. Otherwise, you may damage the
wheels or tires.162
Driving systems
Driving and parking