2019 MERCEDES-BENZ SLC warning

Always make sure that neither you nor the bat-tery is electrostatically charged. A build-up ofelectrostatic charge can be caused, for exam-ple:
Rby wearing clothing made from syntheticfibers
Rdue to friction between clothing and seats
Rif you push or pull the battery across thecarpet or other synthetic materials
Rif you wipe the battery with a cloth
GWARNING
During the charging process, a battery pro-
duces 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
contact with vehicle parts.
RNever place metal objects or tools on a
battery.
RIt is important that you observe the
described order of the battery terminals
when connecting and disconnecting a bat-
tery.
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
batteries. Wash away battery acid immedi-
ately with plenty of clean water and seek
medical attention.
HEnvironmental note
Batteries contain pollutants.
It is illegal to dispose of
them with the household
rubbish. They must be col-
lected separately and dis-
posed of in an environmen-
tally responsible recycling
system.
Dispose of batteries in an
environmentally responsible
manner. Take discharged
batteries to a qualified spe-
cialist workshop or to a col-
lection point for used bat-
teries.
!Have the battery regularly checked at aqualified specialist workshop.
Comply with the service intervals in theMaintenance Booklet, or contact a qualifiedspecialist workshop for more information.
!Always have work on batteries carried outat a qualified specialist workshop.
Should it, in exceptional circumstances, beabsolutely necessary to disconnect the 12-volt battery yourself, please observe the fol-lowing:
RSecure the vehicle to prevent it from roll-ing away.
RSwitch off the ignition.
RDisconnect the negative terminal first andthen the positive terminal.
The transmission is locked in position]after disconnecting the battery.
After the work has been done, install thebattery and replace the cover of the positiveterminal clamp firmly.
Comply with safety precautions and take pro-tective measures when handling batteries.
Risk of explosion.
Fire, open flames and smoking areprohibited when handling the bat-tery. Avoid creating sparks.
258Battery (vehicle)
Breakdo wn assis tan ce

Battery acid is caustic. Avoid con-tact with skin, eyes or clothing.
Wear suitable protective clothing,especially gloves, apron and face-guard.
Rinse any acid spills immediatelywith clear water. Contact a physi-cian 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 havebeen tested and approved for your vehicle byMercedes-Benz. These batteries provideincreased impact protection to prevent vehicleoccupants from suffering acid burns shouldthe battery be damaged in the event of anaccident.
In order for the battery to achieve the maxi-mum possible service life, it must always besufficiently charged.
Like other batteries, the vehicle battery maydischarge over time if you do not use the vehi-cle. In this case, have the battery disconnec-ted at a qualified specialist workshop. You canalso charge the battery with a charger recom-mended by Mercedes-Benz. Contact a quali-fied specialist workshop for further informa-tion.
Have the battery condition of charge checkedmore frequently if you use the vehicle mainlyfor short trips or if you leave it standing idlefor a lengthy period. Consult a qualified spe-cialist workshop if you wish to leave your vehi-cle parked for a long period of time.
Remove the SmartKey if you park the vehicleand do not require any electrical consumers.The vehicle will then use very little energy,thus conserving battery power.
If the power supply has been interrupted, e.g.if you reconnect the battery, you will have to:
Rreset the function for automatically foldingthe exterior mirrors in/out by folding themirrors out once (Ypage 93)
Rset the clock
On vehicles with a multimedia system, thetime is set automatically.
Charging the battery
GWARNING
During charging and jump-starting, explosive
gases can escape from the battery. There is
a risk of an explosion.
Particularly avoid fire, open flames, creating
sparks and smoking. Ensure there is suffi-
cient ventilation while charging and jump-
starting. Do not lean over a battery.
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
batteries. Wash away battery acid immedi-
ately with plenty of clean water and seek
medical attention.
GWARNING
A discharged battery can freeze at tempera-
tures below freezing point. When jump-start-
ing 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.
!Only use battery chargers with a maximumcharging voltage of 14.8V.
!Onlycharge the battery using the jump-starting connection point.
The jump-starting connection point is in theengine compartment.
Battery (vehicle)259
Breakdown assistance
Z

If the indicator/warning lamps do not light upat low temperatures, it is very likely that thedischarged 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 char-acteristics can be impaired, particularly at lowtemperatures. Have the thawed-out batterychecked at a qualified specialist workshop.
Read the battery charger's operating instruc-tions before charging the battery.
XOpen the hood.
XConnect the battery charger to the positiveterminal and ground point in the same orderas when connecting the donor battery in thejump-starting procedure (Ypage 260).
Replacing the 12 V battery
Observe the notes on the 12 V battery(Ypage 257).
Mercedes-Benz recommends that you havethe 12 V battery replaced at a qualified spe-cialist workshop, e.g. at an authorizedMercedes-Benz Center.
If you want to replace the battery yourself,observe the following notes:
RAlways replace a defective battery with abattery which meets the specific require-ments of the vehicle.
The vehicle is equipped with an AGM(Absorbent Glass Mat) technology battery.Full vehicle functionality is only guaranteedwith an AGM battery. For safety reasons,Mercedes-Benz recommends that you onlyuse batteries which have been tested andapproved for your vehicle by Mercedes-Benz.
RUse detachable parts such as breatherhoses, angled connecting pieces or terminalcovers from the battery which is to bereplaced.
RMake sure that the vent hose is always con-nected to the original opening on the bat-tery side.
RInstall existing or supplied cell caps to pre-vent gases or battery acid from escaping.
RMake sure that the detachable parts areconnected again in the same way.
Jump-starting
For the jump-starting procedure, use only the jump-starting connection point in the engine com-partment, consisting of a positive terminal and a ground point.
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 batteries. Wash away battery acid immediately with plenty of
clean water and seek medical attention.
GWARNING
During charging and jump-starting, explosive gases can escape from the battery. There is a
risk of an explosion.
Particularly avoid fire, open flames, creating sparks and smoking. Ensure there is sufficient
ventilation while charging and jump-starting. Do not lean over a battery.
GWARNING
During the charging process, a battery produces hydrogen gas. If a short circuit occurs or
sparks are created, the hydrogen gas can ignite. There is a risk of an explosion.
260Jump-starting
Breakdown assistance

RMake sure that the positive terminal of a connected battery does not come into contact with
vehicle parts.
RNever place metal objects or tools on a battery.
RIt is important that you observe the described order of the battery terminals when connect-
ing 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 disconnect-
ing the jumper cables.
RNever connect or disconnect the battery terminals while the engine is running.
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 explo-
sion.
Allow the frozen battery to thaw out before charging it or jump-starting.
!Avoid repeated and lengthy starting attempts. Otherwise, the catalytic converter could bedamaged by the non-combusted fuel.
If the indicator/warning lamps do not light up at low temperatures, it is very likely that the dis-charged battery has frozen. In this case, you may neither charge the battery nor jump-start thevehicle. The service life of a thawed-out battery may be shorter. The starting characteristics canbe impaired, particularly at low temperatures. Have the thawed-out battery checked at a quali-fied specialist workshop.
Do not start the vehicle using a rapid charging device. If your vehicle's battery is discharged, theengine can be jump-started from another vehicle or from a donor 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 donor battery or a jump-starting device.
RYou may only jump-start the vehicle when the engine and exhaust system are cold.
RDo not start the engine if the battery is frozen. Let the battery thaw first.
ROnly jump-start from batteries with a 12 V voltage rating.
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 connectedfor 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 thejumper cables are connected to the battery.
RThe jumper cables cannot come into contact with parts which can move when the engine isrunning, such as the V-belt pulley or the fan.
XSecure the vehicle by applying the electric parking brake.
XShift the transmission to position].
XMake sure that the ignition is switched off. All indicator lamps in the instrument cluster mustbe off. When using the SmartKey, turn the SmartKey to position

Towing and tow-starting
Important safety notes
GWARNING
When towing or tow-starting another vehicle
and its weight is greater than the permissi-
ble 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 vehi-
cle, its weight should not be greater than
the permissible gross weight of your vehicle.
Details on the permissible gross vehicle weightof your vehicle can be found on the vehicleidentification plate (Ypage 297).
!When Active Brake Assist, Active DistanceAssist DISTRONIC or the HOLD function isactivated, the vehicle brakes automaticallyin certain situations.
To avoid damage to the vehicle, deactivatethese systems in the following or similar sit-uations:
Rwhen towing the vehicle
Rin the car wash
!Only secure the tow rope or tow bar at thetowing eyes. Otherwise, the vehicle could bedamaged.
!Do not use the towing eye for recovery,this could damage the vehicle. If in doubt,recover the vehicle with a crane.
!When towing, pull away slowly andsmoothly. If the tractive power is too high,the vehicles could be damaged.
!Do not tow with sling-type equipment. Thiscould damage the vehicle.
!When towing away vehicles with KEYLESS-GO, use the key instead of the Start/Stopbutton. The automatic transmission mayotherwise shift to position]when youopen the driver's or front-passenger door,which could damage the transmission.
!Make sure that the electric parking brakeis released. If the electric parking brake isfaulty, visit a qualified specialist workshop.
!You may tow the vehicle for a maximumdistance of 30 miles (50 kilometers). A tow-ing speed of 30 mph (50 km/h) must not beexceeded.
For towing distances over 30 miles(50 kilometers), the entire vehicle must beraised and transported.
!When you are tow-starting or towinganother vehicle, its weight must not exceedthe maximum permissible gross weight ofyour vehicle.
It is better to have the vehicle transportedthan to have it towed away.
The automatic transmission must be in posi-tion\\when the vehicle is being towed away.
The battery must be connected and charged.Otherwise, you:
Rcannot turn the SmartKey to positionHinthe ignition lock
Rcannot shift the automatic transmission toposition\\
Deactivate the automatic locking featurebefore the vehicle is towed (Ypage 178). Youcould otherwise be locked out when pushingor 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 particu-
lar care when removing the rear cover.
Towing and tow-starting263
Breakdown assistance
Z

The brackets for the screw-in towing eye arelocated in the bumpers. They are at the frontand at the rear, behind the covers.
XRemove the towing eye from the vehicle toolkit (Ypage 252).
XPress the mark on coverCinwards in thedirection of the arrow.
XTake coverCoff the opening.
XScrew in the towing eye clockwise as far asit will go and tighten it.
Removing the towing eye
XUnscrew and remove the towing eye.
XAttach coverCto the bumper and pressuntil it engages.
XPlace the towing eye in the vehicle tool kit.
Towing a vehicle with both axles on
the ground
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.
The automatic transmission shifts to position]automatically when you open the driver'sor front-passenger door or when you removethe SmartKey from the ignition lock.
In order to ensure that the automatic trans-mission stays in position\\when towingaway the vehicle, you must observe the follow-ing points:
XSwitch on the hazard warning lamps(Ypage 99).
XTurn the SmartKey to positionHin the igni-tion lock.
On vehicles with KEYLESS-GO, use theSmartKey instead of the Start/Stop button(Ypage 118).
XDepress and hold the brake pedal.
XShift the transmission to position\\.
XRelease the brake pedal.
XRelease the electric parking brake.
XLeave the SmartKey in positionHin theignition lock.
In order to signal a change of direction whentowing the vehicle with the hazard warninglamps switched on, use the combinationswitch as usual. In this case, only the indicatorlamps for the direction of travel flash. Whenyou reset the combination switch, the hazardwarning flashers start flashing again.
It is important that you observe the safetyinstructions when towing away your vehicle(Ypage 263).
Permitted towing methods
Mercedes-Benz recommends transporting yourvehicle in the case of a breakdown, rather thantowing it away.
When towing away, use a towing rope or atowing bar with both axles on the ground. Donot use any tow bar systems.
Towing the vehicle with the rear axle
raised
!The ignition must be switched off if youare towing the vehicle with the rear axle
raised. Intervention by ESP®could other-wise damage the brake system.
!Vehicles with automatic transmission mustnot be towed with the rear axle raised. Thevehicle/trailer combination may otherwiseswerve or even roll over.
264Towing and tow-starting
Breakdown assistance

Important safety notes
GWARNING
If you install wheels and tires with incorrect
dimensions, the service brake or wheel sus-
pension components may be damaged.
There is a risk of an accident.
Always replace wheels and tires with ones
that comply with the specifications of the
original part.
When replacing wheels, pay attention to the:
RDesignation
RModel
When replacing tires, pay attention to the:
RDesignation
RManufacturer
RModel
GWARNING
A flat tire will severely affect the driving
characteristics as well as the steering and
braking of the vehicle. There is a risk of an
accident.
Tires without run-flat characteristics:
RDo not drive on with a flat tire.
RChange the flat tire immediately with an
emergency spare wheel or spare wheel.
Alternatively, consult a qualified specialist
workshop.
Tires with run-flat characteristics:
RObserve the information and warning
notes on MOExtended tires (run-flat tires).
Accessories that are not approved for yourvehicle by Mercedes-Benz or are not beingused correctly can impair the operating safety.
Before purchasing and using non-approvedaccessories, visit a qualified specialist work-shop and ask about:
Rsuitability
Rlegal stipulations
Rfactory recommendations
Further information regarding wheels and tirescan be found under "Wheel/tire combinations"(Ypage 292).
You can ask for information regarding permit-ted wheel/tire combinations at an authorizedMercedes-Benz Center.
Information on tire pressure can be found:
Ron the Tire and Loading Information placardon the B-pillar on the driver's side(Ypage 279)
Rin the tire pressure table in the fuel filler flap(Ypage 133)
Rin the "Tire pressure" section
Operation
Information on driving
Check the tire pressure when the vehicle isheavily laden and adjust prior to a trip.
While driving, pay attention to vibrations,noises and unusual handling characteristics,e.g. pulling to one side. This may indicate thatthe wheels or tires are damaged. If you sus-pect that a tire is defective, reduce your speedimmediately. Stop the vehicle as soon as pos-sible to check the wheels and tires for dam-age. Hidden tire damage could also be causingthe unusual handling characteristics. If youfind no signs of damage, have the tires andwheels checked at a qualified specialist work-shop.
When parking your vehicle, make sure that thetires do not get deformed by the curb or otherobstacles. If they cannot be avoided, driveover obstacles such as curbs slowly and at anobtuse angle. Otherwise, you may damage thewheels or tires.
Regular checking of wheels and tires
GWARNING
Damaged tires can cause tire inflation pres-
sure loss. As a result, you could lose control
of your vehicle. There is a risk of accident.
Check the tires regularly for signs of dam-
age and replace any damaged tires immedi-
ately.
Operation267
Wheels and ti res
Z

Check wheels and tires for damage at leastonce a month. Check wheels and tires afterdriving off-road or on rough roads. Damagedwheels can cause a loss of tire pressure. Payparticular attention to damage such as:
Rcuts in the tires
Rpunctures in the tires
Rtears in the tires
Rbulges on tires
Rdeformation or severe corrosion on wheels
Regularly check the tire tread depth and thecondition of the tread across the whole widthof all tires (Ypage 268). If necessary, turn thefront wheels to full lock in order to inspect theinner side of the tire surface.
All wheels must have a valve cap to protectthe valve against dirt and moisture. Do notmount anything onto the valve other than thestandard valve cap or other valve capsapproved by Mercedes-Benz for your vehicle.Do not use any other valve caps or systems,e.g. tire pressure monitoring systems.
Regularly check the pressure of all the tiresparticularly prior to long trips. Adjust the tirepressure as necessary (Ypage 270).
Observe the notes on the emergency sparewheel (Ypage 293).
The service life of tires depends, among otherthings, on the following factors:
RDriving style
RTire pressure
RDistance covered
Notes on tire tread
GWARNING
If there is insufficient tire tread, the tire trac-
tion decreases. The tire tread is no longer
able to dissipate water. This increases the
risk of hydroplaning when the road surface
is wet, particularly when the vehicle's speed
is not adapted to the road conditions. There
is a risk of an accident.
When the tire pressure is too high or too
low, tires may wear differently at different
points on the tire tread. Therefore, regularly
check the tire tread depth and the condition
of the tread across the whole width of all
tires.
Minimum tire tread depth on:
RSummer tires: