2017 MERCEDES-BENZ CLA maintenance

Overview of climate control systems
General notes Observe the settings recommended on the fol-
lowing pages. The windows could otherwise fog
up.
To prevent the windows from fogging up: R
switch off climate control only briefly R
switch on air-recirculation mode only briefly R
switch on the cooling with air dehumidifica-
tion function R
switch on the defrost windshield function
briefly, if required
The air-conditioning system or dual-zone auto-
matic climate control regulates the temperature
and the humidity of the vehicle interior and fil-
ters undesirable substances from the air.
The air-conditioning system or dual-zone auto-
matic climate control can only be operated
when the engine is running. Optimum operation
is only achieved with the side windows and pan-
orama roof with power tilt/sliding panel closed.
If you start the engine using your smartphone,
the last selected climate control setting is reac-
tivated ( Y
page 122).
The residual heat function can only be activated
or deactivated with the ignition switched off
( Y
page 118). Always keep the ventilation flaps behind the
side trim panel in the cargo compartment clear
( Y
page 105). Otherwise the vehicle will not be
ventilated correctly.
i Ventilate the vehicle for a brief period during
warm weather, e.g. using the convenience
opening feature ( Y
page 82). This will speed
up the cooling process and the desired inte-
rior temperature will be reached more
quickly.
i The integrated filter filters out most parti-
cles of dust and soot and completely filters
out pollen. It also reduces gaseous pollutants
and odors. A clogged filter reduces the
amount of air supplied to the vehicle interior.
For this reason, you should always observe
the interval for replacing the filter, which is
specified in the Maintenance Booklet. As it
depends on environmental conditions, e.g.
heavy air pollution, the interval may be
shorter than stated in the Maintenance Book-
let.
i It is possible that under certain circumstan-
ces the residual heat function may be activa-
ted automatically an hour after the SmartKey
has been removed in order to dry the aut o-
mat ic climate control. The vehicle is then ven-
tilated for 30 minutes.Overview of climate control systems 109
Climate control

vice or maintenance work. There is a risk of
injury.
Always secure the engine against uninten-
tional starting before carrying out mainte-
nance or repair work.
Make sure that the engine cannot be started via
your smartphone before carrying out mainte-
nance or repairs. You can prevent an engine
start via your smartphone, for example, if you: R
switch on the hazard warning lamps R
do not lock the doors R
open the hood
Pulling away
General notes
G WARNING
If the engine speed is above the idling speed
and you engage transmission position D or R ,
the vehicle could pull away suddenly. There is
a risk of an accident.
When engaging transmission position D or R ,
always firmly depress the brake pedal and do
not simultaneously accelerate.
Depress the accelerator carefully when pulling
away.
The vehicle locks centrally once you have pulled
away. The locking knobs in the doors drop down.
You can open the doors from the inside at any
time.
You can also deactivate the automatic locking
feature ( Y
page 184).
It is only possible to shift the transmission from
position P to the desired position if you depress
the brake pedal. Only then can the parking lock
be deactivated.
All vehicles (except Mercedes-AMG vehi-
cles): if you do not depress the brake pedal, the
DIRECT SELECT lever can still be moved but the
parking lock remains engaged.
Mercedes-AMG vehicles: if you do not depress
the brake pedal, the selector lever can still be
moved but the parking lock remains engaged.
At transmission fluid temperatures below

Drivin g tips
General notes
Important safet y notes
G WARNING
If you switch of f th e ignition whil e driving,
safety-relevant function s are only available
wit h limitations, or no t at all. Thi s could affect,
fo r example, th e powe r steerin g and th e brake
boostin g effect . You will require considerably
more effort to steer and brake . There is a ris k
of an accident.
Do no t switch of f th e ignition whil e driving.
G WARNING
If you operat e mobile communication equip -
men t whil e driving, you will be distracted from
traffic conditions. You could also los e contro l
of th e vehicle. There is a ris k of an accident.
Only operat e this equipmen t when th e vehicle
is stationary.
Observ e th e lega l requirements fo r th e country
in whic h you are driving. Some jurisdiction s pro -
hibi t th e driver from usin g a mobile phone whil e
drivin g a vehicle.
If you mak e a cal l whil e driving, always use
hands-free mode. Only operat e th e telephon e
when th e traffic situation permits. If you are
unsure , pull over to a saf e location and stop
befor e operatin g th e telephone.
Bear in min d that at a speed of only 30 mph
(approximately 50 km/h), th e vehicle cover s a
distanc e of 44 ft (approximately 14 m) per sec-
ond.
Drive sensibly – save fuel Observe the following tips to save fuel: R
The tires should always be inflated to the rec-
ommended tire pressure. R
Remove unnecessary loads. R
Remove roof racks when they are not needed. R
Warm up the engine at low engine speeds. R
Avoid frequent acceleration or braking. R
Have all maintenance work carried out as
indicated by the service intervals in the Main- tenance Booklet or by the service interval dis-
play.
Fuel consumption also increases when driving in
cold weather, in stop-start traffic and in hilly ter-
rain.
Drinking and driving
G WARNING
Drinking and driving and/or taking drugs and
driving are very dangerous combinations.
Even a small amount of alcohol or drugs can
affect your reflexes, perceptions and judg-
ment.
The possibility of a serious or even fatal acci-
dent is greatly increased when you drink or
take drugs and drive.
Do not drink or take drugs and drive or allow
anyone to drive who has been drinking or tak-
ing drugs.
Emission control
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.
Certain engine systems are designed to keep
the level of poisonous components in exhaust
fumes within legal limits.
These systems only work at peak efficiency if
they are serviced exactly in accordance with the
manufacturer's specifications. Always have
work on the engine carried out at a qualified
specialist workshop. Mercedes-Benz recom-
mends that you use an authorized Mercedes-
Benz Center for this purpose. In particular, work
relevant to safety or on safety-related systems
must be carried out at a qualified specialist
workshop.
The engine settings must not be changed under
any circumstances. Furthermore, all specific
service work must be carried out at regular
intervals and in accordance with the Mercedes-
Benz service requirements. Details can be found
in the Maintenance Booklet. Driving tips 143
Driving and 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

Engine compartment
Hood
Important safety notes
G WARNING
If the hood is unlatched, it may open up when
the vehicle is in motion and block your view.
There is a risk of an accident.
Never unlatch the hood while driving. Before
every trip, ensure that the hood is locked.
G WARNING
When opening and closing the hood, it may
suddenly fall into the closed position. There is
a risk of injury to persons within range of
movement of the hood.
Open and close the hood only when no one is
within its range of movement.
G WARNING
Opening the hood when the engine is over-
heated or when there is a fire in the engine
compartment could expose you to hot gases
or other service products. There is a risk of
injury.
Let an overheated engine cool down before
opening the hood. If there is a fire in the
engine compartment, keep the hood closed
and contact the fire department.
G WARNING
The engine compartment contains moving
components. Certain components, such as
the radiator fan, may continue to run or start
again suddenly when the ignition is off. There
is a risk of injury.
If you need to do any work inside the engine
compartment: R
switch off the ignition R
never reach into the area where there is a
risk of danger from moving components,
such as the fan rotation area R
remove jewelry and watches R
keep items of clothing and hair, for exam-
ple, away from moving parts
G WARNING
The ignition system and the fuel injection sys-
tem work under high voltage. If you touch
components which are under voltage, you
could get an electric shock. There is a risk of
injury.
Never touch components of the ignition sys-
tem or fuel injection system when the ignition
is switched on.
Opening the hood
G WARNING
Certain components in the engine compart-
ment, such as the engine, radiator and parts
of the exhaust system, can become very hot.
Working in the engine compartment poses a
risk of injury.
Where possible, let the engine cool down and
touch only the components described in the
following.
G WARNING
When the hood is open and the windshield
wipers are set in motion, you can be injured by
the wiper linkage. There is a risk of injury.
Always switch off the windshield wipers and
the ignition before opening the hood.
! Make sure that the windshield wipers are
not folded away from the windshield. You
could otherwise damage the windshield wip-
ers or the hood.254
Engine compartment
Maintenance and care

ASSYST PLUS
Service message The ASSYS T PLU S servic e interval display
inform s you of th e next servic e due date.
You can fin d information on th e typ e of servic e
and servic e intervals in th e Maintenance Book -
let .
You can obtain further information from an
authorize d Mercedes-Benz Cente r or at
http://www.mbusa.co m (US A only).
i The ASSYS T PLU S servic e interval display
does no t sho w any information on th e engin e
oil level. Observ e th e note s on th e engin e oil
level ( Y
page 255).
The multifunction display shows a servic e mes -
sage for several seconds, e.g. :R
Servic e A in .. day sR
Servic e A dueR
Servic e A overdu e by .. day s
Dependin g on th e operating condition s of th e
vehicle, th e remaining time or distanc e until th e
next servic e due dat e is displayed.
The lette r A or B , possibl y in connection wit h a
number or another letter, indicates th e typ e of
service. A stand s for a minor servic e and B for a
major service.
You can obtain further information from an
authorize d Mercedes-Benz Center.
The ASSYS T PLU S servic e interval display does
no t tak e int o accoun t any periods of time during
whic h th e battery is disconnected.
Maintainin g th e time-dependen t servic e sched-
ule: X
Not e down th e servic e due dat e displayed in
th e multifunction display before disconnect -
ing th e battery.
or X
Afte r reconnecting th e battery, subtrac t th e
battery disconnection periods from th e ser -
vic e dat e shown on th e display.
Hiding a service message X
Press th e v or 8 butto n on th e steering
wheel. Displaying service messages X
Switc h on th e ignition .X
Press th e Y or e butto n to select th e
Serv. menu. X
Press th e c or d butto n to select th e
ASSYST PLU S submen u and confirm by press-
ing th e v button.
The servic e due dat e appear s in th e multi-
function display.
Infor ma ti on about Service
Resetting the ASSYST PLUS service
interval display
! If th e ASSYS T PLU S servic e interval display
has been inadvertentl y reset , this setting can
be correcte d at a qualified specialist work-
shop.
Hav e servic e wor k carrie d out as described in
th e Maintenance Booklet . This may otherwise
lead to increased wear and damag e to th e
major assemblies or th e vehicle.
A qualified specialist workshop , e.g. an author-
ized Mercedes-Benz Center, will reset th e
ASSYS T PLU S servic e interval display after th e
servic e wor k has been carrie d out . You can also
obtain further information on maintenance
work, for example.
Special service requirements The specifie d maintenance interval takes only
th e normal operation of th e vehicl e int o
account. Under arduous operating condition s or
increased load on th e vehicle, maintenance
wor k mus t be carrie d out mor e frequently, for
example: R
regular cit y drivin g wit h frequen t intermediat e
stops R
if th e vehicl e is primarily used to travel short
distances R
use in mountainous terrain or on poor road
surfaces R
if th e engin e is often lef t idlin g for lon g periodsR
in particularly dust y conditions, or if air-recir-
culation mod e is frequentl y used
In these or similar operating conditions, hav e
th e interior filter, engin e air cleaner, engin e oil
and oil filter, for example, changed mor e fre-258
ASSYST PLUS
Maintenance and care

quently. Under arduous operating conditions,
the tires must be checked more often. Further
information can be obtained at a qualified spe-
cialist workshop, e.g. an authorized Mercedes-
Benz Center.
Driving abroad An extensive Mercedes-Benz Service network is
also available in other countries. You can obtain
further information from any authorized
Mercedes-Benz Center.
Care
General notes
H Environmental note
Dispose of empty packaging and cleaning
cloths in an environmentally responsible man-
ner.
! For cleaning your vehicle, do not use any of
the following: R
dry, rough or hard cloths R
abrasive cleaning agents R
solvents R
cleaning agents containing solvents
Do not scrub.
Do not touch the surfaces or protective films
with hard objects, e.g. a ring or ice scraper.
You could otherwise scratch or damage the
surfaces and protective film.
! Do not park your vehicle for a long period of
time directly after cleaning, particularly after
cleaning the wheel rim with wheel cleaner.
Wheel cleaner can lead to the increased cor-
rosion of the brake discs and pads. Therefore,
drive for a few minutes after cleaning. By
heating up the brakes, the brake discs and
pads dry. The vehicle can then be parked for a
long period of time.
Regular care of your vehicle is a condition for
retaining the quality in the long term.
Use care products and cleaning agents recom-
mended and approved by Mercedes-Benz. Washing the vehicle and cleaning the
paintwork
Automatic car wash
G WARNING
Braking efficiency is reduced after washing
the vehicle. There is a risk of an accident.
After the vehicle has been washed, brake
carefully while paying attention to the traffic
conditions until full braking power is restored.
! When Distance Pilot DISTRONIC or the
HOLD function is activated, the vehicle
brakes automatically in certain situations.
To avoid damage to the vehicle, deactivate
Distance Pilot DISTRONIC and the HOLD
function in the following or similar situations: R
when towing the vehicle R
in the car wash
! Never clean your vehicle in a Touchless
Automatic Car Wash as these use special
cleaning agents. These cleaning agents can
damage the paintwork or plastic parts.
! Make sure that the automatic transmission
is in position N when washing your vehicle in
a tow-through car wash. The vehicle could be
damaged if the transmission is in another
position.
! Make sure that: R
the side windows and the sliding sunroof
are fully closed. R
the ventilation/heating is switched off (the
OFF button has been pressed/the airflow
control is set to position 0 ).R
the windshield wiper switch is in position 0 .
Otherwise, the vehicle might be damaged.
You can wash the vehicle in an automatic car
wash from the very start.
If the vehicle is very dirty, pre-wash it before
cleaning it in an automatic car wash.
After using an automatic car wash, wipe off wax
from the windshield and the wiper blades. This
will prevent smears and reduce wiping noises
caused by residue on the windshield. Care 259
Maintenance and care Z

Washing by hand In some countries, washing by hand is only
allowed at specially equipped washing bays.
Observe the legal requirements in each country. X
Do not use hot water and do not wash the
vehicle in direct sunlight. X
Use a soft sponge to clean. X
Use a mild cleaning agent, such as a car
shampoo approved by Mercedes-Benz. X
Thoroughly hose down the vehicle with a gen-
tle jet of water. X
Do not point the water jet directly towards the
air inlet. X
Use plenty of water and rinse out the sponge
frequently. X
Rinse the vehicle with clean water and dry
thoroughly with a chamois. X
Do not let the cleaning agent dry on the paint-
work.
Carefully remove all deposits of road salt as
soon as possible when driving in winter.
Power washers
G WARNING
The water jet from a circular jet nozzle (dirt
blasters) can cause invisible exterior damage
to the tires or chassis components. Compo-
nents damaged in this way may fail unexpect-
edly. There is a risk of an accident.
Do not use power washers with circular jet
nozzles to clean the vehicle. Have damaged
tires or chassis components replaced imme-
diately.
! Always maintain a distance of at least
11.8 in (30 cm) between the vehicle and the
power washer nozzle. Information about the
correct distance is available from the equip-
ment manufacturer.
Move the power washer nozzle around when
cleaning your vehicle.
Do not aim directly at any of the following: R
Tires R
Door gaps, roof gaps, joints, etc. R
Electrical components R
Battery R
Connectors R
Lamps R
Seals R
Trim R
Ventilation slots
Damaged seals or electrical components can
lead to leaks or failures.
! Vehicles with decorative film: parts of your
vehicle are covered with a decorative film.
Maintain a distance of at least 27.5 in (70 cm)
between the parts of the vehicle covered with
the film and the nozzle of the high pressure
cleaner.
Information about the correct distance is
available from the equipment manufacturer.
Move the power washer nozzle around when
cleaning your vehicle.
Cleaning the paintwork
! Do not affix: R
stickers R
films R
magnetic plates or similar items
to painted surfaces. You could otherwise
damage the paintwork.
Scratches, corrosive deposits, areas affected by
corrosion and damage caused by inadequate
care cannot always be completely repaired. In
such cases, visit a qualified specialist workshop. X
Remove dirt immediately, where possible,
while avoiding rubbing too hard. X
Soak insect remains with insect remover and
rinse off the treated areas afterwards. X
Soak bird droppings with water and rinse off
the treated areas afterwards. X
Remove coolant, brake fluid, tree resin, oils,
fuels and greases by rubbing gently with a
cloth soaked in petroleum ether or lighter
fluid. X
Use tar remover to remove tar stains. X
Use silicone remover to remove wax.
If water no longer forms "beads" on the paint
surface, use the paint care products recommen-
ded and approved by Mercedes-Benz. This is the
case approximately every three to five months,
depending on the climate conditions and the
care product used.
If dirt has penetrated the paint surface or if the
paint has become dull, the paint cleaner recom-260
Care
Maintenance and care