2018 MERCEDES-BENZ CLS ECU

R
Make sure that the positive terminal of a
connected battery does not come into con-
tact with vehicle parts. R
Never place metal objects or tools on a bat-
tery. R
It is important that you observe the descri-
bed 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 dis-
connecting the jumper cables. R
Never connect or disconnect the battery
terminals while the engine is running.
G WARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with skin, eyes or clothing. Do
not inhale any battery gases. Do not lean over
the battery. Keep children away from batter-
ies. Wash away battery acid immediately with
plenty of clean water and seek medical atten-
tion.
H Environmental note
Batteries contain dangerous
substances. It is against the
law to dispose of them with
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.
! Always have work on batteries carried out at
a qualified specialist workshop. Should it, in
exceptional circumstances, be absolutely
necessary to disconnect the 12-volt battery
yourself, observe the following: R
secure the vehicle to prevent it from rolling
away. R
switch off the ignition. R
always disconnect the negative terminal
clamp first, followed by the positive termi-
nal clamp.
After the battery has been disconnected, the
transmission is locked in position P .
After the work has been done, install the bat-
tery and replace the cover of the positive ter-
minal clamp firmly.
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 byBattery (vehicle) 283
Breakdown assistance Z

Removing the towing eye X
Unscrew and remove the towing eye. X
Position cover C on top of the bumper and
press it in at the bottom until it engages. X
Attach cover D to the bumper and press until
it engages. X
Place the towing eye in the vehicle tool kit.
Towing a vehicle with both axles on
the ground It is important that you observe the safety
instructions when towing away your vehicle
( Y
page 287).
The automatic transmission automatically shifts
to position P when you open the driver's or front-
passenger door or when you remove the Smart-
Key from the ignition lock. In order to ensure
that the automatic transmission stays in posi-
tion N when towing the vehicle, you must
observe the following points: X
Make sure that the vehicle is stationary. X
Turn the SmartKey to position 2 in the ignition
lock.
On vehicles with KEYLESS-GO, use the Smart-
Key instead of the Start/Stop button
( Y
page 124). X
Depress and hold the brake pedal. X
Shift the automatic transmission to position
N . X
Release the brake pedal. X
Release the parking brake. X
Switch on the hazard warning lamps
( Y
page 107). X
Leave the SmartKey in position 2 in the igni-
tion lock.
In order to signal a change of direction when
towing the vehicle with the hazard warning
lamps switched on, use the combination switch
as usual. In this case, only the turn signals for
the desired direction flash. After resetting the
combination switch, the hazard warning lamp
starts flashing again. Towing the vehicle with the rear axle
raised
! Vehicles with 4MATIC must not be towed
with either the front or the rear axle raised, as
doing so will damage the transmission.
! Vehicles with automatic transmission must
not be towed with the rear axle raised. The
vehicle/trailer combination may otherwise
swerve or even roll over.
Transporting the vehicle
4MATIC vehicles/vehicles with auto-
matic transmission
! When the vehicle is loaded for transport, the
front and rear axles must be stationary and on
the same transportation vehicle. Positioning
over the connection point of the transport
vehicle is not permitted. The drive train may
otherwise be damaged.
All vehicles
! You may only secure the vehicle by the
wheels, not by parts of the vehicle such as
axle or steering components. Otherwise, the
vehicle could be damaged.
The towing eye can be used to pull the vehicle
onto a trailer or transporter for transporting pur-
poses. X
Turn the SmartKey to position 2 in the ignition
lock. X
Shift the automatic transmission to position
N .Towing and tow-starting 289
Breakdown assistance Z

As soon as the vehicle has been loaded:X
Prevent the veh icle from rolling away by
applyin g the parking brake.X
Sh ift the automat ic transmission to posi-
tion P .X
Turn the Sm artKey to position 0 in the ignition
lock and remove it. X
Secure the veh icle .
Notes on 4MATIC vehicles
! Veh icle s wit h 4MATIC must not be towed
wit h either the front or the rear axle raised, as
doin g so will damage the transmission.
If the veh icle has transmission damage or dam-
age to the front or rear axle, have it transported
on a transporter or trailer.
In the event of da ma ge to the electrical sys-
tem
If the battery is defective, the automat ic trans-
mission will be locked in position P . To shift the
automat ic transmission to position N , you must
pro vide power to the veh icle 's electrical system
in the same way as when jump-starting
( Y
page 285).
Have the veh icle transported on a transporter or
trailer.
Tow-starting (emergency engine
starting)
! Veh icle s wit h automat ic transmission must
not be started by tow-starting. This could oth-
erwise damage the transmission.
i You can find information on "Jump-starting"
under ( Y
page 285).
Fuses
Important safety notes
G WAR NING
If you man ipulat e or brid ge a faulty fuse or if
you replace it wit h a fuse wit h a higher amper-
age, the electr ic cables could be overloaded.
This could result in a fire. There is a risk of an
acc iden t and injury. Alwa ys replace faulty fuses wit h the specified
new fuses having the correct amperage.
Blo wn fuses must be replaced wit h fuses of the
same rating, whic h you can recognize by the
color and value. The fuse ratings are listed in the
fuse allocation chart.
The fuse allocation chart is located in the vehicle
tool kit in the stowage compartment under the
trunk floor ( Y
page 277).
If a ne wly inserted fuse also blows, have the
cause traced and rectified at a qualified special-
ist worksho p, e.g. an authorized Mercedes-Benz
Center.
! Only use fuses that have been appr oved for
Mercedes-Benz vehicles and whic h have the
correct fuse rating for the system concerned.
Otherwise, components or systems could be
damaged.
! Make sure that no moisture can enter the
fuse box when the cover is open.
! When closing the cover, make sure that it is
lying correctly on the fuse box. Moisture seep-
ing in or dirt could otherwise impair the oper-
ation of the fuses.
The fuses in your vehicle ser ve to close down
faulty circuits. If a fuse blows, all the compo-
nents on the circuit and their functions stop
operating.
Before changing a fuse Pay attention to the important safety notes
( Y
page 290). X
Swit ch off the engine. X
Swit ch off all electrical consumers. X
Make sure that the ignition is swit ched off
( Y
page 123).
or X
When using the SmartKey, turn the SmartKey
to position 0 in the ignition lock and remove it
( Y
page 123). X
Secure the vehicle against rolling away
( Y
page 141).
All indicator lamps in the instrument cluster
must be off.290
Fuses
Breakdown assistance

The fuses are located in various fuse boxes: R
Fuse box in the engine compartment on the
left-hand side of the vehicle, when viewed in
the direction of travel R
Fuse box in the trunk on the right-hand side of
the vehicle, when viewed in the direction of
travel
Fuse box in the engine compartment Pay attention to the important safety notes
( Y
page 290).
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.
X
Make sure that the windshield wipers are
turned off. X
Open the hood ( Y
page 265).X
Use a dry cloth to remove any moisture from
the fuse box. X
To open: take lines C out of the guides.X
Move lines C to one side.X
Open retaining clamps D .X
Remove the fuse box cover forwards. X
To close: check whether the seal is lying cor-
rectly in the cover. X
Insert the cover at the rear of the fuse box into
the retainer. X
Fold down the cover and close clamps D .X
Secure lines C in the guides.X
Close the hood. Fuse box in the trunk Pay attention to the important safety notes
( Y
page 290).
X
Open the trunk lid. X
To open: release cover C at the top right and
left-hand sides with a flat object. X
Open cover C downwards in the direction of
the arrow. Fuses 291
Breakdown assistance Z

Overinflated tires may: R
increase the braking distance R
adversely affect handling R
wear excessively and/or unevenly R
have an adverse effect on ride comfort R
be more susceptible to damage
Maximum tire pressures
C
Example: maximum permissible tire pres-
sure
Never exceed the maximum permissible tire
inflation pressure. Always observe the recom-
mended tire pressure for your vehicle when
adjusting the tire pressure ( Y
page 295).
i The actual values for tires are vehicle-spe-
cific and may deviate from the values in the
illustration.
Checking the tire pressures
Important safety notes Observe the notes on tire pressure
( Y
page 295).
Information on air pressure for the tires on your
vehicle can be found: R
on the vehicle's Tire and Loading Information
placard on the B-pillar R
in the tire pressure table in the fuel filler flap
( Y
page 139)R
in the "Tire pressure" section Checking tire pressures manually To determine and set the correct tire pressure,
proceed as follows: X
Remove the valve cap of the tire that is to be
checked. X
Press the tire pressure gauge securely onto
the valve. X
Read the tire pressure and compare it to the
recommended value on the Tire and Loading
Information placard or the tire pressure table
( Y
page 295). X
If the tire pressure is too low, increase the tire
pressure to the recommended value. X
If the tire pressure is too high, release air. To
do so, press down the metal pin in the valve,
using the tip of a pen for example. Then check
the tire pressure again using the tire pressure
checker. X
Screw the valve cap onto the valve. X
Repeat these steps for the other tires.
Tire pressure loss warning system
(Canada only)
General notes While the vehicle is in motion, the tire pressure
loss warning system monitors the set tire pres-
sure using the rotational speed of the wheels.
This enables the system to detect significant
pressure loss in a tire. If the speed of rotation of
a wheel changes as a result of a loss of pressure,
a corresponding warning message will appear in
the multifunction display.
You can recognize the tire pressure loss warning
by the Run Flat Indicator Active Press
'OK' to Restart message which appears in
the Serv. menu of the multifunction display.
Information on the message display can be
found in the "Restarting the tire pressure loss
warning system" section ( Y
page 299).
Important safety notes
The tire pressure warning system does not warn
you of an incorrectly set tire pressure. Observe
the notes on the recommended tire pressure
( Y
page 295).
The tire pressure loss warning does not replace
the need to regularly check the tire pressure. An
even loss of pressure on several tires at the298
Tire pressure
Wheels and tires

Speed rating The speed rating is part of the tire identification.
It specifies the speed range for which the tire is
approved.
GVW (Gross Vehicle Weight) The gross vehicle weight includes the weight of
the vehicle including fuel, tools, the spare wheel,
accessories installed, occupants, luggage and
the drawbar noseweight, if applicable. The gross
vehicle weight must not exceed the gross vehi-
cle weight rating GVWR as specified on the vehi-
cle identification plate on the B-pillar on the
driver's side.
GVWR (Gross Vehicle Weight Rating) The GVWR is the maximum permissible gross
weight of a fully loaded vehicle (the weight of the
vehicle including all accessories, occupants,
fuel, luggage and the drawbar noseweight, if
applicable). The gross vehicle weight rating is
specified on the vehicle identification plate on
the B-pillar on the driver's side.
Maximum loaded vehicle weight The maximum weight is the sum of: R
the curb weight of the vehicle R
the weight of the accessories R
the load limit R
the weight of the factory installed optional
equipment
Kilopascal (kPa) Metric unit for tire pressure. 6.9 kPa corre-
sponds to 1 psi. Another unit for tire pressure is
bar. 100 kilopascals (kPa) are the equivalent of
1 bar.
Load index
In addition to the load-bearing index, the load
index may also be imprinted on the sidewall of
the tire. This specifies the load-bearing capacity
more precisely.
Curb weight
The weight of a vehicle with standard equipment
including the maximum capacity of fuel, oil and
coolant. It also includes the air-conditioning sys-
tem and optional equipment if these are instal-
led in the vehicle, but does not include passen-
gers or luggage. Maximum load rating The maximum tire load is the maximum permis-
sible weight in kilograms or lbs for which a tire is
approved.
Maximum permissible tire pressure Maximum permissible tire pressure for one tire.
Maximum load on one tire Maximum load on one tire. This is calculated by
dividing the maximum axle load of one axle by
two.
PSI (pounds per square inch) A standard unit of measure for tire pressure.
Aspect ratio Relationship between tire height and tire width
in percent.
tire pressure Pressure inside the tire applying an outward
force to every square inch of the tire's surface.
The tire pressure is specified in pounds per
square inch (psi), in kilopascal (kPa) or in bar.
The tire pressure should only be corrected when
the tires are cold.
Cold tire pressure The tires are cold: R
if the vehicle has been parked with the tires
out of direct sunlight for at least three hours
and R
if the vehicle has not been driven further than
1 mile (1.6 km)
Tread
The part of the tire that comes into contact with
the road.
Bead
The tire bead ensures that the tire sits securely
on the wheel. There are several steel wires in the
bead to prevent the tire from coming loose from
the wheel rim.
Sidewall
The part of the tire between the tread and the
bead.All about wheels and tires 311
Wheels and tires Z

Direction of rotation Tires wit h a specifie d direction of rotation hav e
additional benefits, e.g. if there is a ris k of hydro-
planing. These advantages can only be gained if
th e tires are installed correspondin g to th e
direction of rotation .
An arrow on th e sidewall of th e tire indicates it s
correc t direction of rotation .
Storing wheel sStor e wheels that are no t bein g used in a cool,
dry and preferably dar k place. Protec t th e tires
from oil, grease , gasolin e and diesel.
Mounting a wheel
Preparing th e vehicleX
Stop th e vehicle on solid, non-slipper y and
level ground. X
Apply th e parking brake .X
Brin g th e fron t wheels into th e straight-ahead
position .X
Shift th e transmissio n to position P .X
Vehicles wit h AIRMATIC : mak e sur e that "nor-
mal" level is selecte d ( Y
page 159).X
Switc h of f th e engine.X
Remov e th e SmartKey from th e ignition lock.
or , on vehicles wit h KEYLESS ‑ GO :X
Ope n th e driver's door.
The vehicle electronic s no w hav e status 0 .
Thi s is th e sam e as th e SmartKey havin g bee n
removed. X
Remov e th e Start/Sto p butto n from th e igni-
tion loc k ( Y
page 123).X
If included in th e vehicle equipment, remov e
th e tire-chang e tool ki t from th e vehicle
( Y
page 277). X
Safeguar d th e vehicle against rollin g away. Securing th e vehicle to preven t it from
rollin g awa y
If your vehicle is equipped wit h a whee l chock, it
can be found in th e tire-chang e tool ki t
( Y
page 277).
The foldin g whee l choc k is an additional safet y
measur e to preven t th e vehicle from rollin g
away, fo r example when changin g a wheel.X
Fold bot h plates upwards C .X
Fold out lowe r plat e D .X
Guide th e lugs on th e lowe r plat e full y into th e
opening s in base plat e

must be positioned vertically, directly under
the jacking point of the vehicle.
! The jack is designed exclusively for jacking
up the vehicle at the jacking points. Other-
wise, your vehicle could be damaged.
Observe the following when raising the vehicle: R
To raise the vehicle, only use the vehicle-spe-
cific jack that has been tested and approved
by Mercedes-Benz. If used incorrectly, the
jack could tip over with the vehicle raised. R
The jack is designed only to raise and hold the
vehicle for a short time while a wheel is being
changed. It must not be used for performing
maintenance work under the vehicle. R
Avoid changing the wheel on uphill and down-
hill slopes. R
Before raising the vehicle, secure it from roll-
ing away by applying the parking brake and
inserting wheel chocks. Do not disengage the
parking brake while the vehicle is raised. R
The jack must be placed on a firm, flat and
non-slip surface. On a loose surface, a large,
flat, load-bearing underlay must be used. On a
slippery surface, a non-slip underlay must be
used, e.g. rubber mats. R
Do not use wooden blocks or similar objects
as a jack underlay. Otherwise, the jack will not
be able to achieve its load-bearing capacity
due to the restricted height. R
Make sure that the distance between the
underside of the tires and the ground does not
exceed 1.2 in (3 cm). R
Never place your hands and feet under the
raised vehicle. R
Do not lie under the vehicle. R
Do not start the engine when the vehicle is
raised. R
Do not open or close a door or the trunk lid
when the vehicle is raised. R
Make sure that no persons are present in the
vehicle when the vehicle is raised.
Vehicles with alloy wheels and hub caps: the
wheel bolts are covered by a hub cap. Before y ou
ca n unscrew the wheel bolts, you must remove
the hub cap. X
To remove: take socket D and lug wrench