key MERCEDES-BENZ CLS 2018 Service Manual

Rear-compartment overhead control
panel
C
= Switches the right-hand reading lamp
on/offD
= Switches the left-hand reading lamp
on/off
Interior lighting control
General notes In order to prevent the vehicle's battery from
discharging, the interior lighting functions are
automatically deactivated after some time
except for when the SmartKey is in position 2 in
the ignition lock.
The color and brightness of the ambient lighting
may be set using the on-board computer
( Y
page 198).
Automatic interior lighting control X
To switch on or off: press the 3 button.
When the automatic interior lighting control is
activated, the button is flush with the over-
head control panel.
The interior lighting automatically switches on if
you: R
unlock the vehicle R
open a door. R
remove the SmartKey from the ignition lock
The interior light is activated for a short while
when the SmartKey is removed from the ignition
lock. You can activate this delayed switch-off
using the on-board computer ( Y
page 199). Replacing bulbs The front and rear light clusters of your vehicle
are equipped with LED light bulbs. Do not
replace the LED light sources of your vehicle
yourself. Contact a qualified specialist work-
shop which has the necessary specialist knowl-
edge and tools to carry out the work required.
Lamps are an important aspect of vehicle safety.
You must therefore make sure that these func-
tion correctly at all times. Have the headlamp
setting checked regularly.
Windshield wipers
Switching the windshield wipers
on/off
! Do not operate the windshield wipers when
the windshield is dry, as this could damage
the wiper blades. Moreover, dust that has col-
lected on the windshield can scratch the glass
if wiping takes place when the windshield is
dry.
If it is necessary to switch on the windshield
wipers in dry weather conditions, always use
washer fluid when operating the windshield
wipers.
! If the windshield wipers leave smears on the
windshield after the vehicle has been washed
in an automatic car wash, wax or other resi-
dues may be the reason for this. Clean the
windshield using washer fluid after washing
the vehicle in an automatic car wash.
! Intermittent wiping with rain sensor: due to
optical influences and the windshield becom-
ing dirty in dry weather conditions, the wind-
shield wipers may be activated inadvertently.
This could then damage the windshield wiper
blades or scratch the windshield.
For this reason, you should always switch off
the windshield wipers in dry weather.Windshield wipers 109
Lights and windshield wipers Z

Problems with the windshield wipers Problem
Possible causes/consequences and P Solutions
The windshield wipers
are jammed. Leaves or snow, for example, are obstructing windshield wiper move-
ment. The wiper motor has been deactivated. X
Switch off the engine. X
Remove the SmartKey from the ignition lock.
or, on vehicles with KEYLESS ‑ GO:X
Open the driver's door.
The vehicle electronics now have status 0 . This is the same as the
SmartKey having been removed. X
Remove the cause of the obstruction. X
Switch the windshield wipers back on.
The windshield wipers
fail completely. The windshield wiper drive is malfunctioning. X
Select another wiper speed on the combination switch. X
Have the windshield wipers checked at a qualified specialist work-
shop.
The windshield washer
fluid from the spray noz-
zles no longer hits the
center of the windshield. The spray nozzles are misaligned. X
Have the spray nozzles adjusted at a qualified specialist workshop. Windshield wipers 111
Lights and windshield wipers Z

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
Climate control regulates the temperature and
the humidity in the vehicle interior and filters
undesirable substances out of the air.
Climate control can only be operated when the
engine is running. Optimum operation is only
achieved with the side windows and roof closed.
The residual heat function can only be activated
or deactivated with the ignition switched off
( Y
page 120). i Ventilate the vehicle for a brief period during
warm weather, e.g. using the convenience
opening feature ( Y
page 88). 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 the residual heat function
may be activated automatically an hour after
the SmartKey is removed. The vehicle is then
ventilated for 30 minutes to dry the automatic
climate control.
Control panel for dual-zone automatic climate control
Canada only
C
Sets the temperature, left ( Y
page 117)
D
Defrosts the windshield ( Y
page 118)

Problems with the "Cooling with air dehumidification" function Problem
Possible causes/consequences and P Solutions
The indicator lamp in the
Z button flashes
three times or remains
off. The "Cooling with air
dehumidification" func-
tion cannot be switched
on. Cooling with air dehumidification has been deactivated due to a mal-
function. X
Visit a qualified specialist workshop.
Setting climate control to automatic
General notes In automatic mode, the set temperature is main-
tained automatically at a constant level. The
system automatically regulates the temperature
of the dispensed air, the airflow and the air dis-
tribution.
The "Cooling with air dehumidification" function
is activated automatically in automatic mode.
Automatic control X
Turn the SmartKey to position 2 in the ignition
lock ( Y
page 123).X
Set the desired temperature. X
To switch on: press the X button.
The indicator lamp in the X button lights
up. Automatic air distribution and airflow are
activated.
3-zone automatic climate control: when auto-
matic mode is activated, you can set the climate
mode ( Y
page 117).X
To switch to manual mode: press the

Switch off the "Windshield defrosting" function
as soon as the windshield is clear again. X
Turn the SmartKey to position 2 in the ignition
lock ( Y
page 123).X
To activate: press the d button.
The indicator lamp in the d button lights
up.
The climate control system switches to the
following functions: R
high airflow R
high temperature R
air distribution to the windshield and front
side windows R
air-recirculation mode off
If the battery is not sufficiently charged, blower
output may be reduced. Once the battery is suf-
ficiently charged again, full blower output will be
available again. X
To deactivate: press the d button.
The indicator lamp in the d button goes
out. The previously selected settings are
restored. Air-recirculation mode remains
deactivated.
MAX COOL maximum cooling The MAX COOL function is only available in vehi-
cles for the USA.
MAX COOL is only operational when the engine
is running. X
To activate: press the

Problems with the rear window defroster Problem
Possible causes/consequences and P Solutions
The rear window
defroster has deactiva-
ted prematurely or can-
not be activated. The battery has not been sufficiently charged. X
Switch off any consumers that are not required, e.g. reading lamps,
interior lighting or the seat heating.
When the battery is sufficiently charged, the rear window defroster
can be activated again.
Switching air-recirculation mode
on/off
General notes You can deactivate the flow of fresh air if
unpleasant odors are entering the vehicle from
outside. The air already inside the vehicle will
then be recirculated.
If you switch on air-recirculation mode, the win-
dows can fog up more quickly, in particular at
low temperatures. Only use air-recirculation
mode briefly to prevent the windows from fog-
ging up.
Activating/deactivating X
Turn the SmartKey to position 2 in the ignition
lock ( Y
page 123).X
To activate: press the r button.
The indicator lamp in the r button lights
up.
Dual-zone automatic climate control: air-recir-
culation mode is automatically activated at high
outside temperatures.
3-zone automatic climate control: air-recircula-
tion mode is automatically activated at high lev-
els of pollution or at high outside temperatures.
When air-recirculation mode is activated auto-
matically, the indicator lamp above the r
button does not light up. Outside air is added
after approximately 30 minutes. X
To deactivate: press the r button.
The indicator lamp in the r button goes
out. Air-recirculation mode deactivates automati-
cally: R
after approximately five minutes at outside
temperatures below approximately 41 ‡
(5 †) R
after approximately five minutes if cooling
with air dehumidification is deactivated R
after approximately 30 minutes at outside
temperatures above approximately 41 ‡
(5 †) if the "Cooling with air dehumidifica-
tion" function is activated
Switching the residual heat on or off
General notes The residual heat function is only available with
3-zone automatic climate control.
It is possible to make use of the residual heat of
the engine to continue heating the vehicle for
approximately 30 minutes after the engine has
been switched off. The heating time depends on
the set interior temperature.
Activating/deactivating X
Turn the SmartKey to position 0 in the ignition
lock or remove it ( Y
page 123).X
To switch on: press the K button.
The indicator lamp in the K button lights
up.
If the residual heat function is activated, the
windows may fog up on the inside.
The blower will run at a low speed regardless of
the airflow setting.
If you activate the residual heat function at high
temperatures, only the ventilation will be acti-
vated. The blower runs at medium speed.120
Operating the climate control systems
Climate control

for example, the power steering and the brake
boosting effect. You will require considerably
more effort to steer and brake. There is a risk
of an accident.
Do not switch off the ignition while driving.
G WARNING
If the parking brake has not been fully
released when driving, the parking brake can: R
overheat and cause a fire R
lose its hold function.
There is a risk of fire and an accident. Release
the parking brake fully before driving off.
! Do not warm up the engine with the vehicle
stationary. Drive off immediately. Avoid high
engine speeds and driving at full throttle until
the engine has reached its operating temper-
ature.
Only shift the automatic transmission to the
desired drive position when the vehicle is sta-
tionary.
Where possible, avoid spinning the drive
wheels when pulling away on slippery roads.
You could otherwise damage the drive train.
! Mercedes-AMG vehicles: at low engine oil
temperatures below 68 ‡ (+20 †), the max-
imum engine speed is restricted in order to
protect the engine. To protect the engine and
maintain smooth engine operation, avoid driv-
ing at full throttle when the engine is cold. Key positions
SmartKey
Z
To remove the SmartKey
(shift the transmission to position P )G
Power supply for some consumers, such as
the windshield wipers H
Ignition (power supply for all consumers)
and drive position I
To start the engine
i The SmartKey can be turned in the ignition
lock even if it is not the correct SmartKey for
the vehicle. The ignition is not switched on.
The engine cannot be started.
KEYLESS-GO
General notes Vehicles with KEYLESS-GO are equipped with
SmartKeys featuring the integrated KEYLESS-
GO function and a detachable Start/Stop but-
ton.
The Start/Stop button must be inserted in the
ignition lock and the SmartKey must be in the
vehicle.
When you insert the Start/Stop button into the
ignition lock, the system needs approximately
two seconds recognition time. You can then use
the Start/Stop button.
Pressing the Start/Stop button several times in
succession corresponds to the different Smart-
Key positions in the ignition lock. This is only the
case if you are not depressing the brake pedal.
If you depress the brake pedal and press the
Start/Stop button, the engine starts immedi-
ately.
A check which periodically establishes a radio
connection between the vehicle and the Smart-
Key determines whether a valid SmartKey is in Driving 123
Driving and parking Z

the vehicle. This occurs, for example, when
starting the engine.
To start the vehicle without actively using the
SmartKey: R
the Start/Stop button must be inserted in the
ignition lock. R
the SmartKey must be in the vehicle. R
the vehicle must not be locked with the
SmartKey or KEYLESS-GO ( Y
page 76).
Do not keep the KEYLESS-GO key: R
with electronic devices, e.g. a mobile phone
or another SmartKey. R
with metallic objects, e.g. coins or metal foil. R
inside metallic objects, e.g. a metal case.
This can affect the functionality of KEYLESS-GO.
If you lock the vehicle with the SmartKey's
remote control or with KEYLESS-GO, after a
short time: R
you will not be able to switch on the ignition
with the Start/Stop button. R
you will not be able to start the engine with the
Start/Stop button until the vehicle is
unlocked again.
The engine can be switched off while the vehicle
is in motion by pressing and holding the Start/
Stop button for three seconds. This function
operates independently of the ECO start/stop
automatic engine switch-off function.
Key positions with KEYLESS-GO
C
Start/Stop button
D
Ignition lock
As soon as the ignition is switched on, all the
indicator lamps in the instrument cluster light
up. Indicator and warning lamps, see
( Y
page 226). 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 deactivated
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.
It is only possible to switch between Start/Stop
button mode and SmartKey operation when the
transmission is in 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
vehi cle. 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.124
Driving
Dr ivi ng an d parking

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 PR
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.
G WARNING
Flammable materials introduced through
environmental influence or by animals can
ignite if in contact with the exhaust system or
parts of the engine that heat up. There is a risk
of fire.
Carry out regular checks to make sure that
there are no flammable foreign materials in
the engine compartment or in the exhaust
system.
General notes
i The catalytic converter is preheated for up
to 30 seconds after a cold start. The sound of
the engine may change during this time.
Automatic transmission X
Shift the transmission to position P .
The transmission position display in the mul-
tifunction display shows P .
i You can start the engine in transmission
position P and N . Starting procedure with the SmartKey
i To start the engine using the SmartKey
instead of KEYLESS-GO, pull the Start/Stop
button out of the ignition lock. X
Turn the SmartKey to position 3 in the ignition
lock ( Y
page 123 )a nd release it as soon as the
engine is running.
Using KEYLESS-GO to start the engine
i The Start/Stop button can be used to start
the vehicle manually without inserting the
SmartKey into the ignition lock. The Start/
Stop button must be inserted in the ignition
lock and the SmartKey must be in the vehicle.
This mode for starting the engine operates
independently of the ECO start/stop auto-
matic engine start function. X
Depress the brake pedal and keep it
depressed. X
Press the Start/Stop button once
( Y
page 123).
The engine starts.
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.
! If a warning tone sounds and the Release
Park. Brake message appears in the multi-
function display, the parking brake is still
applied. Release the parking brake.
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 199).Driving 125
Driving an d parking Z

X
To deactivate: press ECO button C .
Indicator lamp D goes out.X
To activate: press ECO button C .
Indicator lamp D lights up.
If indicator lamp D is off, the ECO start/stop
function has been deactivated manually or as the result of a malfunction. The engine will then
not be switched off automatically when the vehi-
cle stops.
Problems with the engine Problem
Possible causes/consequences and P Solutions
The engine does not
start. The HOLD function or DISTRONIC PLUS is activated. X
Deactivate the HOLD function ( Y
page 157) or DISTRONIC PLUS
( Y
page 155). X
Try to start the engine again.
The engine does not
start. The starter motor
can be heard. R
There is a malfunction in the engine electronics. R
There is a malfunction in the fuel supply.
Before attempting to start the engine again: X
Turn the SmartKey back to position 0 in the ignition lock.
or X
Press the Start/Stop button repeatedly until all indicator lamps in
the instrument cluster go out. X
Try to start the engine again ( Y
page 124). Avoid excessively long
and frequent attempts to start the engine as these will drain the
battery.
If the engine does not start after several attempts: X
Consult a qualified specialist workshop.
The engine does not
start. You cannot hear
the starter motor. The on-board voltage is too low because the battery is too weak or
discharged. X
Jump-start the vehicle ( Y
page 285).
If the engine does not start despite attempts to jump-start it: X
Consult a qualified specialist workshop.
The starter motor was exposed to a thermal load that was too high. X
Allow the starter motor to cool down for approximately two minutes. X
Try to start the engine again.
If the engine still does not start: X
Consult a qualified specialist workshop.128
Driving
Driving an d parking