2018 MERCEDES-BENZ C-CLASS SEDAN ECU

The highly flammable gas mixture forms when
charging the battery as well as when jump-start-
ing.
Always make sure that neither you nor the bat-
tery is electrostatically charged. A build-up of
electrostatic charge can be caused, for exam-
ple:
Rby wearing clothing made from synthetic
fibers
Rdue to friction between clothing and seats
Rif you push or pull the battery across the car-
pet or other synthetic materials
Rif you rub the battery with a cloth
GWARNING
During the charging process, a battery produ-
ces hydrogen gas. If a short circuit occurs or
sparks are created, the hydrogen gas can
ignite. There is a risk of an explosion.
RMake sure that the positive terminal of a
connected battery does not come into con- tact with vehicle parts.
RNever place metal objects or tools on a bat-
tery.
RIt is important that you observe the descri-
bed order of the battery terminals when
connecting and disconnecting a battery.
RWhen jump-starting, make sure that the
battery poles with identical polarity are
connected.
RIt is particularly important to observe the
described order when connecting and dis-
connecting the jumper cables.
RNever connect or disconnect the battery
terminals while the engine is running.
GWARNING
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.
All vehicles:
HEnvironmental 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, please observe the fol-
lowing:
RSecure the vehicle to prevent it from rolling
away.
RSwitch off the ignition.
RDisconnect the negative terminal first and
then the positive terminal.
The transmission is locked in position j
after disconnecting the battery.
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 (vehicle)323
Breakdown assistance
Z

GWARNING
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.
If the warning and indicator lamps do not light up on the instrument cluster when temperatures are low, it is probably because the discharged battery has frozen. In this case, you may neither charge
the battery nor jump-start the vehicle. 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.
All vehicles:
!Vehicles with a gasoline engine: avoid repeated and lengthy starting attempts. Otherwise, the
catalytic converter could be damaged by non-combusted fuel.
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:
RThe 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.
RVehicles with a gasoline engine: only jump-start the vehicle when the engine and exhaust
system are cold.
RAll vehicles except vehicles with a lithium-ion battery: do not start the engine if the battery
is frozen. Let the battery thaw first.
RJump-starting may be performed only using batteries with a nominal voltage of 12 V.
ROnly use jumper cables which have a sufficient cross-section and insulated terminal clamps.
RIf the battery is fully discharged, leave the battery that is being used to jump-start connected for
a few minutes before attempting to start. This charges the battery slightly.
RMake sure that the two vehicles do not touch.
Make sure that:
RThe jumper cables are not damaged.
RBare parts of the terminal clamp do not come into contact with other metal parts while the jumper
cables are connected to the battery.
RThe jumper cables cannot come into contact with parts that can move when the engine is running,
such as the V-belt pulley or the fan.
XSecure the vehicle by applying the electric parking brake.
XShift the transmission to position j.
XMake sure that the ignition is switched off. All indicator lamps in the instrument cluster must be
off. When using the SmartKey, turn the SmartKey to position uin the ignition lock and remove it
(
Ypage 136).
XSwitch off all electrical consumers, e.g. rear window defroster, lighting, etc.
XOpen the hood.
326Jump-starting
Breakdown assistance

If your vehicle is being towed, much more
force may be necessary to steer or brake.
There is a risk of an accident.
In such cases, use a tow bar. Before towing,
make sure that the steering moves freely.
GWARNING
You can no longer steer the vehicle if the
steering wheel lock has been engaged. There
is a risk of an accident.
Always switch off the ignition when towing the
vehicle with a tow cable or a tow bar.
GWARNING
When towing or tow-starting another vehicle
and its weight is greater than the permissible
gross weight of your vehicle, the:
Rthe towing eye could detach itself
Rthe vehicle/trailer combination could roll-
over.
There is a risk of an accident.
When towing or tow-starting another vehicle,
its weight should not be greater than the per- missible gross weight of your vehicle.
Details on the permissible gross vehicle weight
of your vehicle can be found on the vehicle iden-
tification plate (
Ypage 360).
!When Active Brake Assist, Distance Pilot
DISTRONIC or the HOLD function is activated,
the vehicle brakes automatically in certain
situations.
To avoid damage to the vehicle, deactivate
these systems in the following or similar sit-
uations:
Rwhen towing the vehicle
Rin the car wash
!Make sure that the electric parking brake is
released. If the electric parking brake is faulty,
visit a qualified specialist workshop.
!Secure the tow rope or tow bar to the towing
eye only. Otherwise, the vehicle could
become damaged.
!Do not use the towing eye for recovery. This
could damage the vehicle. If in doubt, have
the vehicle recovered using a crane.
!When towing, pull away slowly and
smoothly. If the tractive power is too high, the
vehicles could be damaged.
!Shift the automatic transmission to position
i and do not open the driver's or front pas-
senger's door during towing. The automatic
transmission may otherwise shift to position
j, which could damage the transmission.
!Do not tow with sling-type equipment. This
could damage the vehicle.
!The vehicle can be towed a maximum of
30 miles (50km). The towing speed of 30 mph (50 km/h) must not be exceeded.
If the vehicle has to be towed more than
30 miles (50km), the entire vehicle must be
raised and transported.
It is better to have the vehicle transported than
to have it towed away.
If the vehicle has suffered transmission damage,
have it transported on a transporter or trailer.
The automatic transmission must be in position
i w

hen the vehicle is being towed. If the auto-
matic transmission cannot be shifted to position
i, have the vehicle transported on a trans-
porter or trailer.
The battery must be connected and charged.
Otherwise, you:
Rcannot turn the SmartKey to position 2in
the ignition lock
Rcannot release the electric parking brake
Rcannot shift the automatic transmission to
position i
Disarm the automatic locking feature before the vehicle is towed (
Ypage 85). You could other-
wise be locked out when pushing or towing the
vehicle.
Installing/removing the towing eye
Installing the towing eye
GWARNING
The exhaust tail pipe may be very hot. There is
a risk of burns when removing the rear cover.
Do not touch the exhaust pipe. Take particular
care when removing the rear cover.
328Towing and tow-starting
Breakdown assistance

vehicle is not permitted. The drive train may
otherwise be damaged.
Vehicles with ADS PLUS (Adaptive
Damping System PLUS)
GWARNING
The weaker damping forces of the vehicle to
be transported can cause the vehicle/trailer
combination to swing.
As a result, when transporting vehicles with
Adaptive Damping System PLUS, the vehicle/
trailer combination may start to skid. Conse-
quently, you could lose control of the vehicle.
There is a risk of accident and injury.
When transporting, make sure that:
Rthe vehicle is has been loaded onto the
transporter correctly
Rthe vehicle is secured at all four wheels with
suitable tensioning straps
Ryou do not exceed the maximum permissi-
ble speed of 35 mph (60 km/h)
!After loading, the vehicle must be secured at
all four wheels. Otherwise, the vehicle could
be damaged.
A minimum distance of 8 in (20 cm) up and
4 in (10 cm) down must be maintained to the
transport platform.
XSecure all four wheels after loading the vehi-
cle.
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.
XTurn the SmartKey to position 2in the igni-
tion lock.
XShift the automatic transmission to position
i. As soon as the vehicle has been loaded:
XPrevent the vehicle from rolling away by
applying the electric parking brake.
XShift the automatic transmission to position
j.
XTurn the SmartKey to position
uin the igni-
tion lock and remove it.
XSecure the vehicle.
Notes on 4MATIC vehicles
!
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 4MATIC may either be towed away with both axles on the ground or be loaded up
and transported.
If the vehicle's transmission, front, or rear axle is
damaged, have the vehicle transported on a
truck or trailer.
In the event of damage to the electrical sys-
tem: if the battery is defective, the automatic
transmission will be locked in position P. To shift
the automatic transmission to position N, you
must provide power to the vehicle's electrical
system in the same way as when jump-starting
(
Ypage 325).
Have the vehicle transported on a transporter or
trailer.
Tow-starting (emergency engine
starting)
!
Vehicles with automatic transmission must
not be tow-started. You could otherwise dam-
age the automatic transmission.
iYou can find information on "Jump-starting"
under (Ypage 325).
Fuses
Important safety notes
GWARNING
If you manipulate or bridge a faulty fuse or if
you replace it with a fuse with a higher amper- age, the electric cables could be overloaded.
330Fuses
Breakdown assistance

This could result in a fire. There is a risk of anaccident and injury.
Always replace faulty fuses with the specified
new fuses having the correct amperage.
Blown fuses must be replaced with fuses of the same rating, which you can recognize by the
color and value. The fuse ratings are listed in the
fuse allocation chart.
The fuse allocation chart is on the fuse box in the
trunk (
Ypage 332).
If a newly inserted fuse also blows, have the
cause traced and rectified at a qualified special-
ist workshop, e.g. an authorized Mercedes-Benz
Center.
!Only use fuses that have been approved for
Mercedes-Benz vehicles and which 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 serve 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
Observe the important safety notes
(Ypage 330)
XSwitch off the engine.
XSwitch off all electrical consumers.
XMake sure that the ignition is switched off
(Ypage 137).
or
XWhen using the SmartKey, turn the SmartKey
to position uin the ignition lock and remove
it (
Ypage 136).
XSecure the vehicle against rolling away
(Ypage 161).
All indicator lamps in the instrument cluster
must be off. The fuses are located in various fuse boxes:
RFuse box on the driver's side of the dashboard
RFuse box in the front-passenger footwell
RFuse box in the engine compartment on the
driver's side
RFuse box under the trunk floor on the right-
hand side of the vehicle, when viewed in the
direction of travel
Dashboard fuse box
The fuse box is under a cover on the side of the
dashboard. You can obtain further information
from an authorized Mercedes-Benz Center.
Fuse box in the front-passenger foot-
well
XOpen the front-passenger door.
XTo open: fold cover :out towards the rear
and remove it.
XTo close: clip in cover :at the rear.
XFold cover :forwards until it engages.
Fuse box in the engine compartment
GWARNING
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.
Fuses331
Breakdown assistance
Z

Important safety notes
GWARNING
If wheels and tires of th ewrong siz eare used,
th ewhee lbrakes or suspension component s
may be damaged. Ther eis aris kof an acci-
dent.
Always replace wheels and tires wit hthose
that fulfill th especification sof th eoriginal
part .
When replacing wheels, mak esur eto use th e
correct:
Rdesignation
Rmodel
When replacing tires ,mak esur eto use th e
correct:
Rdesignation
Rmanufacturer
Rmodel
GWARNIN G
A flat tire severely impairs th edriving ,steer -
ing and braking characteristics of th evehicle.
Ther eis aris kof accident.
Tires without run-flat characteristics :
Rdo notdriv ewit h a flat tire.
Rimmediately replace th eflat tire wit hyour
emergenc yspar ewhee lor spar ewheel, or
consult aqualified specialist workshop.
Tires wit hrun-flat characteristics :
Rpay attention to theinformation and warn -
ing notice son MOExtended tires (tire swit h
run-flat characteristics).
Accessories that are no tapprove dfor your vehi-
cle by Mercedes-Ben zor are no tbein gused cor-
rectl ycan impair th eoperating safety.
Before purchasing and usin gnon-approve d
accessories, visit aqualified specialist work-
sho pand inquire about :
Rsuitability
Rlegal stipulation s
Rfactory recommendation sFurther information regarding wheels and tires
can be foun
dunder "Wheel/tire combinations"
(
Ypage 357).
You can ask for information regarding permitte d
wheel-tire combination sat an authorize d
Mercedes-Ben zCenter.
Information on tire pressur ecan be found:
Ron th eTir eand Loading Information placard
on th eB-pillar on th edriver' sside
(
Ypage 343)
Rin th etire pressur etable in th efuel filler flap
(Ypage 336)
Runder "Tir epressure" (Ypage 336)
Operation
Information on driving
Checkth etire pressur ewhen th evehicl eis
heavily laden and adjust prio rto atrip.
While driving ,pay attention to vibrations, noises
and unusual handlin gcharacteristics ,e.g. pull-
ing to on eside .This may indicat ethat th e
wheels or tires are damaged. If you suspec tthat
a tire is defective, reduce your spee dimmedi-
ately. Stop th evehicl eas soo nas possible to
chec kth ewheels and tires for damage. Hidden
tire damag ecould also be causing th eunusual
handlin gcharacteristics .If you fin dno sign sof
damage, hav eth etires and wheels checke dat a
qualified specialist workshop.
When parking your vehicle, mak esur ethat th e
tires do no tget deformed by th ecur bor other
obstacles. If they canno tbe avoided, driv eove r
obstacles suc has curbs slowly and at an obtuse
angle. Otherwise, you may damag eth ewheels
or tires .
Notes on high performance tires
GWARNIN G
Due to th especial tire tread in combination
wit hth eoptimized rubber compound ,there is
an increased ris kof hydroplaning and skid-
din gon damp or wet road surfaces. In addi-
tion ,tire traction is significantly reduce dat
low outside temperatures and low tire-oper -
ating temperatures .Ther eis aris kof an acci-
dent.
Operation333
Wheels and tires
Z

Maximum tire pressures
: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 (
Ypage 336).
iThe 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
(Ypage 336).
Information on air pressure for the tires on your
vehicle can be found:
Ron the vehicle's Tire and Loading Information
placard on the B-pillar
Rin the tire pressure table in the fuel filler flap
(Ypage 156)
Rin the "Tire pressure" section
Checking tire pressures manually
To determine and set the correct tire pressure,
proceed as follows:
XRemove the valve cap of the tire that is to be
checked.
XPress the tire pressure gauge securely onto
the valve.
XRead the tire pressure and compare it to the
recommended value on the Tire and Loading
Information placard or the tire pressure table (
Ypage 336).
XIf the tire pressure is too low, increase the tire
pressure to the recommended value.
XIf 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.
XScrew the valve cap onto the valve.
XRepeat these steps for the other tires.
Tire pressure loss warning system
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 Restartmessage which appears in
the Servicemenu of the multifunction display.
Information on the message display can be
found in the "Restarting the tire pressure loss
warning system" section (
Ypage 340).
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
(
Ypage 336).
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 the
same time cannot be detected by the tire pres-
sure loss warning system.
The tire pressure monitor is not able to warn you
of a sudden loss of pressure, e.g. if the tire is
penetrated by a foreign object. In the event of a
sudden loss of pressure, bring the vehicle to a
halt by braking carefully. Avoid abrupt steering
movements.
The function of the tire pressure loss warning
system is limited or delayed if:
Rsnow chains are mounted on your vehicle's
tires.
Rroad conditions are wintry.
Tire pressure339
Wheels and tires
Z

Ryou are drivingon san dor gravel .
Ryou adop t averysport ydrivin gstyle (corner-
in gat high speeds or drivin gwit hhigh rates of
acceleration).
Ryou are drivin gwit h a heav yload (in th evehi-
cle or on th eroof).
Resta rting the ti repressure loss warn-
ing system
Restart th etire pressur eloss warnin gsystem if
you have:
Rchanged th etire pressur e
Rchanged thewheels or tires
Rmounte dne wwheels or tires
XBefor erestarting ,mak esur ethat th etire
pressures are set properly on all fou rtires for
th erespective operating conditions.
The recommended tire pressur ecan be found
on th eTir eand Loadin gInformation placard
on th eB-pillar .Additionally, atire pressur e
table is attached to th efuel filler flap .The tire
pressur eloss warnin gsystem can only giv e
reliable warnings if you hav eset th ecorrec t
tire pressure. If an incorrec ttire pressur eis
set ,these incorrec tvalue swill be monitored.
XAlso observ eth enote sin th esection on tire
pressures (Ypage 336).
XMakesur ethat th eSmartKey is in position 2
in th eignition loc k (Ypage 136).
XPressòon thesteerin gwhee lto cal lup
th emen ulist .
XPress 9or: on thesteerin gwhee lto
select th eServic emenu.
XConfirmby pressing aon thesteerin g
wheel.
XPress 9or: to select TirePres‐sur e.
XPress ato confirm .
The Run Fla tIndicator ActivePress'OK 'to Restar tmessage is shown in th e
multifunction display.
If you wish to confir mtherestart:
XPress th ea button.
The TirePressure Now OK?message is
shown on th emultifunction display.
XPress 9or: to select Yes.
XPressato confirm .
The Run Fla tIndicator Restartedmes -
sage is shown on th emultifunction display. Afte
r ateach-i nperiod, th etire pressur eloss
warnin gsystem will monitor th eset tire pres-
sures of all fou rtires .
If you wish to cancel th erestart :
XPress th e% button.
or
XIf th eTir ePressure Now OK?message
appears ,press 9or: to select Can‐
cel.
XPress ato confirm .
The tire pressur evalue sstore dat th elast
restar twill continue to be monitored.
Ti re pressure mo nitor
Gene ral notes
Ifatire pressur emonitor is installed ,th evehi-
cle's wheels hav esensor sthat monitor th etire
pressures in all fou rtires .The tire pressur emon -
itor warn syou if th epressur edrops in on eor
mor eof th etires .The tire pressur emonitor only
function sif th ecorrespondin gsensor sare
installed in all wheels.
Information on tire pressures is displayed in th e
multifunction display. Afte r afew minute sof
driving, th ecurren ttire pressur eof eac htire is
shown in th eServic e
menuof th emultifunction
display; see illustration (example).
Information on th emessage display can be
found in th e"Checking th etire pressur eelec -
tronically" section (
Ypage 342).
Important safety notes
GWARNIN G
Eac htire, includin gth espar e(if provided),
should be checke dat leas tonce every tw o
340Tire pressure
Wheels and tires