MERCEDES-BENZ SLC 2019 Workshop Manual

deactivated in accordance with the per-
son in the front-passenger seat
Rthe person is seated properly with a cor-
rectly fastened seatbelt
Rthe front-passenger seat has been moved
as far back as possible
If the PASSENGER AIR BAG OFF indicator
lamp remains lit when it should not, the
front-passenger seat must not be used. Do
not install a child restraint system on the
front-passenger seat. Have the Occupant
Classification System (OCS) checked and
repaired immediately at a qualified specialist
workshop.
GWARNING
Objects between the seat surface and the
child restraint system could affect OCS
operation. This could result in the front-
passenger air bag not functioning as inten-
ded during an accident. This poses an
increased risk of injury or even fatal injury.
Do not place any objects between the seat
surface and the child restraint system. The
entire base of the child restraint system
must always rest on the seat cushion of the
front-passenger seat. The backrest of the
forward-facing child restraint system must,
as far as possible, be resting on the back-
rest of the front-passenger seat. Always
comply with the child restraint system man-
ufacturer's installation instructions.
After the self-test, the PASSENGER AIR BAGOFF or the PASSENGER AIR BAG ON indicatorlamp displays the status of the front-passenger front airbag (Ypage 46). If thefront-passenger front airbag is enabled, thePASSENGER AIR BAG ON indicator lamp lightsup for 60 seconds and then goes out.
If the PASSENGER AIR BAG ON indicator lampis off, only the PASSENGER AIR BAG OFF indi-cator lamp shows the status of the front-passenger front airbag. The PASSENGER AIRBAG OFF indicator lamp may be lit continu-ously or be off.
For more information about the OCS, see"Problems with the Occupant ClassificationSystem" (Ypage 49).
Problems with the Occupant Classification System (OCS)
Be sure to observe the notes on "System self-test" (Ypage 48).
Occupant safety49
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ProblemPossible causes/consequences andPPSolutions
The PASSENGER AIRBAG OFF indicator lamplights up and remainslit, even though thefront-passenger seat isoccupied by an adult ora person of a staturecorresponding to that ofan adult.
The classification of the person on the front-passenger seat is incor-rect.
XMake sure the conditions for a correct classification of the per-son on the front-passenger seat are met (Ypage 46).
XIf the PASSENGER AIR BAG OFF indicator lamp remains lit, thefront-passenger seat may not be used.
XHave OCS checked as soon as possible at an authorizedMercedes-Benz Center.
The PASSENGER AIRBAG OFF indicator lampdoes not light upand/or does not stayon.
The front-passengerseat is:
Runoccupied
Roccupied by theweight of a child upto twelve months oldin a child restraintsystem
OCS is malfunctioning.
XMake sure there is nothing between the seat cushion and thechild seat.
XMake sure that the entire base of the child restraint system restson the seat cushion of the front-passenger seat. The backrest ofthe forward-facing child restraint system must lie as flat as possi-ble against the backrest of the front passenger seat. If necessary,adjust the position of the front-passenger seat.
XWhen installing the child restraint system, make sure that theseat belt is tight. Do not pull the seat belt tight using the front-passenger seat adjustment. This could result in the seat belt andthe child restraint system being pulled too tightly.
XCheck for correct installation of the child restraint system.
Make sure that the head restraint does not apply a load to thechild restraint system. If necessary, adjust the head restraintaccordingly.
XMake sure that no objects are applying additional weight onto theseat.
XIf the PASSENGER AIR BAG OFF indicator lamp remains offand/or the PASSENGER AIR BAG ON indicator lamp lights up, donot install a child restraint system on the front-passenger seat.
XHave OCS checked as soon as possible at an authorizedMercedes-Benz Center.
Deployment of Emergency Tension-
ing Devices and air bags
Important safety notes
GWARNING
The air bag parts are hot after an air bag has
been deployed. There is a risk of injury.
Do not touch the air bag parts. Have a
deployed air bag replaced at a qualified spe-
cialist workshop as soon as possible.
GWARNING
A deployed air bag no longer offers any pro-
tection and cannot provide the intended pro-
tection in an accident. There is an increased
risk of injury.
Have the vehicle towed to a qualified spe-
cialist workshop in order to have a deployed
air bag replaced.
For your own safety and that of your frontpassenger, it is important that you havedeployed air bags replaced and defective airbags repaired. This will help to make sure theair bags continue to perform their protective
50Occupant safety
Safety

function for the vehicle occupants in the eventof a crash.
GWARNING
Emergency Tensioning Devices that have
deployed pyrotechnically are no longer
operational and are unable to perform their
intended protective function. This poses an
increased risk of injury or even fatal injury.
Have pyrotechnically triggered Emergency
Tensioning Devices replaced immediately at
a qualified specialist workshop.
An electric motor is used by PRE-SAFE®totrigger the tightening of the seat belt in haz-ardous situations. This procedure is reversible.
If Emergency Tensioning Devices are triggeredor air bags are deployed, you will hear a bang,and some powder may also be released. Theurestraint system warning lamp lights up.
Only in rare cases will the bang affect yourhearing. The powder that is released generallydoes not constitute a health hazard, but it maycause short-term breathing difficulties in peo-ple with asthma or other respiratory problems.Provided it is safe to do so, you should leavethe vehicle immediately or open the window inorder to prevent breathing difficulties.
Air bags and pyrotechnic Emergency Tension-ing Devices (ETDs) contain perchlorate mate-rial, which may require special handling andregard for the environment. National guide-lines must be observed during disposal. In Cal-ifornia, seewww.dtsc.ca.gov/HazardousWaste/Perchlorate/index.cfm.
Method of operation
During the first stage of a collision, therestraint system control unit evaluates impor-tant physical data relating to vehicle decelera-tion or acceleration, such as:
Rduration
Rdirection
Rintensity
Based on the evaluation of this data, therestraint system control unit triggers the Emer-gency Tensioning Devices during a head-on orrear-end collision.
An Emergency Tensioning Device can only betriggered, if:
Rthe ignition is switched on
Rthe components of the restraint system areoperational. You can find further informationunder "Restraint system warning lamp"(Ypage 39)
Rthe seat belt buckle tongue has engaged inthe belt buckle of the respective seat
If the restraint system control unit detects amore severe accident, further components ofthe restraint system are activated independ-ently of each other in certain frontal collisionsituations:
RFront air bags as well as driver's and front-passenger knee bags
Depending on the person in the front-passenger seat, the front-passenger front airbag is either enabled or disabled. The front-passenger front air bag can be deployed in anaccident only if the PASSENGER AIR BAG OFFindicator lamp is off. Observe the informationon the PASSENGER AIR BAG indicator lamps(Ypage 39).
Your vehicle has two-stage front air bags.
The activation threshold of the EmergencyTensioning Devices and the air bags is deter-mined by evaluating the rate of vehicle decel-eration or acceleration which occurs at variouspoints in the vehicle. This process is pre-emp-tive in nature. Deployment should take placein good time at the start of the collision.
The rate of vehicle deceleration or accelera-tion and the direction of the force are essen-tially determined by:
Rthe distribution of forces during the collision
Rthe collision angle
Rthe deformation characteristics of the vehi-cle
Rthe characteristics of the object with whichthe vehicle has collided
Factors which can only be seen and measuredafter a collision has occurred do not play adecisive role in the deployment of an air bag.Nor do they provide an indication of air bagdeployment.
The vehicle can be deformed considerably,without an air bag being deployed. This is thecase if only parts which are relatively easilydeformed are affected and the rate of deceler-ation is not high. Conversely, air bags may bedeployed even though the vehicle suffers only
Occupant safety51
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minor deformation. This is the case if, forexample, very rigid vehicle parts such as longi-tudinal body members are hit, and sufficientdeceleration occurs as a result.
If the restraint system control unit detects aside impact or if the vehicle rolls over, theapplicable components of the restraint systemare deployed independently of each otherdepending on the apparent type of accident.
RSide impact air bag on the side of impact,independently of the Emergency TensioningDevice and the use of the seat belt on thedriver's seat
The side impact air bag on the frontpassenger side deploys under the followingconditions:
-the OCS system detects that the frontpassenger seat is occupied or
-the seat belt buckle tongue is engaged inthe belt buckle of the front passengerseat
RHead bag on the side of impact, independ-ently of the use of the seat belt and inde-pendently of whether the front-passengerseat is occupied
REmergency Tensioning Devices, if the sys-tem determines that deployment can offeradditional protection in this situation
RHead bags on the driver's and front-passenger side in certain situations whenthe vehicle rolls over, if the system deter-mines that deployment can offer additionalprotection to that provided by the seat belt
iNot all air bags are deployed in an acci-dent. The different air bag systems workindependently of each other.
How the air bag system works is determinedby the severity of the accident detected,especially the vehicle deceleration or accel-eration and the apparent type of accident:
RHead-on collision
RSide impact
RRollover
NECK-PRO head restraints
Important safety notes
GWARNING
The function of the head restraint may be
impaired if you:
Rattach objects such as coat hangers to
the head restraints, for example
Ruse head restraint covers
If you do so, the head restraints cannot fulfill
their intended protective function in the
event of an accident. In addition, objects
attached to the head restraints could endan-
ger other vehicle occupants. There is an
increased risk of injury.
Do not attach any objects to the head
restraints and do not use head restraint cov-
ers.
Method of operation
NECK-PRO head restraints reduce the likeli-hood of head and chest injuries. The NECK-PRO head restraints on the driver's and front-passenger seats are moved forwards andupwards in the event of a rear-end collision ofa certain severity. This provides better headsupport.
If the NECK-PRO head restraints have beentriggered in an accident, you must reset theNECK-PRO head restraints on the driver’s andfront-passenger seat (Ypage 53). Other-wise, the additional protection will not beavailable in the event of another rear-end colli-sion. You can recognize when NECK-PRO headrestraints have been triggered by the fact thatthey have moved forwards and can no longerbe adjusted.
Mercedes-Benz recommends that you havethe NECK-PRO head restraints checked forfunctionality at a qualified specialist workshopafter a rear-end collision.
52Occupant safety
Safety

Resetting triggered NECK-PRO head
restraints
Do not insert your finger between the uphols-tery of the head restraint and the seat. Payparticular attention while resetting the NECK-PRO head restraints.
XTilt the top of the NECK-PRO head restraintcushion forwards in the direction ofarrowC.
XPush the NECK-PRO head restraint cushiondown as far as it will go in the direction ofarrowD.
XFirmly push the NECK-PRO head restraintcushion back in the direction of arrow

GWARNING
If you leave children unsupervised in the
vehicle, they could set it in motion by, for
example:
Rrelease the parking brake.
Rshift the automatic transmission out of
the parking positionP.
Rstart the engine.
In addition, they may operate vehicle equip-
ment and become trapped. 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 unsupervised in the
vehicle.
GWARNING
If persons, particularly children are subjec-
ted to prolonged exposure to extreme heat
or cold, there is a risk of injury, possibly
even fatal. Never leave children unattended
in the vehicle.
GWARNING
If the child restraint system is subjected to
direct sunlight, parts may get very hot. Chil-
dren may burn themselves on these parts,
particularly on the metal parts of the child
restraint system. There is a risk of injury.
If you leave the vehicle, taking the child with
you, always ensure that the child restraint
system is not exposed to direct sunlight.
Protect it with a blanket, for example. If the
child restraint system has been exposed to
direct sunlight, let it cool down before secur-
ing the child in it. Never leave children unat-
tended in the vehicle.
Always ensure that all vehicle occupants havetheir seat belts fastened correctly and are sit-ting properly. Particular attention must be paidto children.
Observe the safety notes on the seat belt(Ypage 40) and the notes on correct use ofseat belts (Ypage 41).
A booster seat may be necessary to achieveproper seat belt positioning for children over
40 lbs (18 kg) until they reach a height wherea three-point seat belt can be properly fas-tened without a booster seat.
Special seatbelt retractor
GWARNING
If the seat belt is released while driving, the
child restraint system will no longer be
secured properly. The special seat belt
retractor is disabled and the inertia real
draws in a portion of the seat belt. The seat
belt cannot be immediately refastened.
There is an increased risk of injury, possibly
even fatal.
Stop the vehicle immediately, paying atten-
tion to road and traffic conditions. Reacti-
vate the special seat belt retractor and
secure the child restraint system properly.
The seat belt on the front-passenger's side isequipped with a special seat belt retractor.When activated, the special seat belt retractorensures that the seat belt cannot slacken oncethe child seat is secured.
Installing a child restraint system:
XMake sure you observe the child restraintsystem manufacturer's installation instruc-tions.
XPull the seat belt smoothly out of the beltloop.
XEngage seat belt tongue in belt buckle.
Activating the special seat belt retractor:
XPull the seat belt out fully and let the inertiareel retract it again.While the seat belt is retracting, you shouldhear a ratcheting sound. The special seatbelt retractor is enabled.
XPush the child restraint system down so thatthe seat belt is tight and does not loosen.
54Children in the vehicle
Safety

Removing the child restraint system and deac-tivating the special seat belt retractor:
XMake sure you observe the child restraintsystem manufacturer's installation instruc-tions.
XPress the release button of the seat beltbuckle, hold the belt tongue and guide itback towards the belt loop.The special seat belt retractor is deactiva-ted.
Child restraint system
The use of seat belts and child restraint sys-tems is required by law in:
Rall 50 states
Rthe U.S. territories
Rthe District of Columbia
Rall Canadian provinces
You can obtain further information about thecorrect child restraint system from any author-ized Mercedes-Benz Center.
GWARNING
If the child restraint system is installed
incorrectly on a suitable seat, it cannot pro-
tect as intended. The child cannot then be
restrained in the event of an accident, heavy
braking or sudden changes of direction.
There is an increased risk of injury, possibly
even fatal.
Make sure that you observe the child
restraint system manufacturer's installation
instructions and the notes on use. Please
ensure, that the base of the child restraint
system is always resting completely on the
seat cushion. Never place objects, e.g. cush-
ions, under or behind the child restraint sys-
tem. Only use child restraint systems with
the original cover designed for them. Only
replace damaged covers with genuine cov-
ers.
GWARNING
If the child restraint system is installed
incorrectly or is not secured, it can come
loose in the event of an accident, heavy
braking or a sudden change in direction. The
child restraint system could be thrown
about, striking vehicle occupants. There is
an increased risk of injury, possibly even
fatal.
Always install child restraint systems prop-
erly, even if they are not being used. Make
sure that you observe the child restraint sys-
tem manufacturer's installation instructions.
Further information on stowing objects, lug-gage and loads securely can be found under“Stowing options/stowage compartments”(Ypage 225).
GWARNING
Child restraint systems or their securing sys-
tems which have been damaged or subjec-
ted to a load in an accident can no longer
protect as intended. The child cannot then
be restrained in the event of an accident,
heavy braking or sudden changes of direc-
tion. There is an increased risk of injury,
possibly even fatal.
Replace child restraint systems which have
been damaged or subjected to a load in an
accident as soon as possible. Have the
securing systems on the child restraint sys-
tem checked at a qualified specialist work-
shop, before you install a child restraint sys-
tem again.
The securing system of child restraint systemsis the seat belt system.
iIf you install a child restraint system onthe front passenger seat, be sure to observethe instructions and safety notes on the"Occupant Classification System (OCS)"(Ypage 46). There you will also find infor-mation on disabling the front passengerfront air bag.
All child restraint systems must meet the fol-lowing standards:
RU.S. Federal Motor Vehicle Safety Standards213 and 225
RCanadian Motor Vehicle Safety Standards213 and 210.2
Confirmation that the child restraint systemcorresponds to the standards can be found onan instruction label on the child restraint sys-
Children in the vehicle55
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tem. This confirmation can also be found inthe installation instructions that are includedwith the child restraint system.
Observe the warning labels in the vehicle inte-rior and on the child restraint system.
Child restraint system on the front-
passenger seat
General notes
If you install a child restraint system on thefront-passenger seat, always observe theinstructions and safety notes on the "Occu-pant Classification System (OCS)" (Ypage 46).
You can thus avoid the risks that could ariseas a result of:
Ran incorrectly categorized person in thefront-passenger seat
Rdeactivating the front passenger front airbag unintentionally
Rthe unsuitable positioning of the childrestraint system, e.g. too close to the dash-board
Rearward-facing child restraint system
If circumstances require you to secure a childin a rearward-facing child restraint system onthe front-passenger seat, always make surethat the front passenger front air bag is deacti-vated. Only if the PASSENGER AIR BAG OFFindicator lamp is lit continuously (Ypage 39),is the front passenger front air bag deactiva-ted.
Always observe the child restraint systemmanufacturer's installation and operatinginstructions.
Forward-facing child restraint system
If you secure a child in a forward-facing childrestraint system on the front-passenger seat,always move the front-passenger seat as farback as possible. The entire base of the childrestraint system must always rest on the seatcushion of the front-passenger seat. The back-rest of the child restraint system must lie asflat as possible against the backrest of thefront-passenger seat. The child restraint sys-tem must not touch the roof or be subjectedto a load by the head restraint. Adjust theangle of the seat backrest and the head
restraint position accordingly. Always makesure that the shoulder belt strap is correctlyrouted from the front-passenger seat beltguide to the shoulder belt guide on the childrestraint system. The shoulder belt strap mustbe routed forward and down from the front-passenger seat belt guide.
Always observe the child restraint systemmanufacturer's installation and operatinginstructions.
Pets in the vehicle
GWARNING
If you leave animals unsupervised or unse-
cured in the vehicle, they may press buttons
or switches, for instance.
In this way, animals may:
Ractivate vehicle equipment and become
trapped, for example
Rswitch systems on or off and thereby
endanger other road users
Furthermore, unsecured animals may be
flung around inside the vehicle in the event
of an accident or abrupt steering or braking
maneuver, and thereby injure vehicle occu-
pants. There is a risk of accident and injury.
Never leave animals unattended in the vehi-
cle.
Always secure animals properly when driv-
ing, for instance with a suitable pet carrier.
Driving safety systems
Overview of driving safety systems
In this section, you will find information aboutthe following driving safety systems:
RABS (Anti-lockBrakingSystem)(Ypage 57)
RBAS (BrakeAssistSystem) (Ypage 57)
RActive Brake Assist (Ypage 58)
RAdaptive brake lights (Ypage 60)
RESP®(ElectronicStabilityProgram)(Ypage 60)
56Driving safety systems
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REBD (ElectronicBrake forceDistribution)(Ypage 63)
RADAPTIVE BRAKE (Ypage 64)
Important safety notes
If you fail to adapt your driving style or if youare inattentive, the driving safety systems canneither reduce the risk of an accident noroverride the laws of physics. Driving safetysystems are merely aids designed to assistdriving.
You are responsible for maintaining the dis-tance to the vehicle in front, for vehicle speed,for braking in good time, and for staying inlane. Always adapt your driving style to suitthe prevailing road and weather conditions andmaintain a safe distance from the vehicle infront. Drive carefully.
The driving safety systems described onlywork as effectively as possible when there isadequate contact between the tires and theroad surface. Pay particular attention to theinformation regarding tires, recommendedminimum tire tread depths etc. in the "Wheelsand tires" section (Ypage 267).
In wintry driving conditions, always use wintertires (M+S tires) and if necessary, snowchains. Only in this way will the driving safetysystems described in this section work aseffectively as possible.
ABS (Anti-lock Braking System)
General information
ABS regulates brake pressure in such a waythat the wheels do not lock when you brake.This allows you to continue steering the vehi-cle when braking.
The%ABS warning lamp in the instrumentcluster lights up when the ignition is switchedon. It goes out when the engine is running.
ABS works from a speed of about 5 mph(8 km/h), regardless of road-surface condi-tions. ABS works on slippery surfaces, evenwhen you only brake gently.
Important safety notes
iObserve the "Important safety notes" sec-tion (Ypage 57).
GWARNING
If ABS is malfunctioning, the wheels could
lock when braking. The steerability and
braking characteristics would be severely
affected. There is an increased danger of
skidding and accidents.
Drive on carefully. Have ABS checked imme-
diately at a qualified specialist workshop.
When ABS is malfunctioning, other systems,including driving safety systems, will alsobecome inoperative. Observe the informationon the ABS warning lamp (Ypage 210) anddisplay messages which may be shown in theinstrument cluster (Ypage 183).
Brakes
XIf ABS intervenes:continue to depress thebrake pedal vigorously until the braking sit-uation is over.
XTo make a full brake application:depressthe brake pedal with full force.
If ABS intervenes when braking, you will feel apulsing in the brake pedal.
The pulsating brake pedal can be an indicationof hazardous road conditions, and functions asa reminder to take extra care while driving.
BAS (Brake Assist System)
General information
BAS operates in emergency braking situations.If you depress the brake pedal quickly, BASautomatically boosts the braking force, thusshortening the stopping distance.
Important safety notes
iObserve the "Important safety notes" sec-tion (Ypage 57).
Driving safety systems57
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GWARNING
If BAS is malfunctioning, the braking dis-
tance in an emergency braking situation is
increased. There is a risk of an accident.
In an emergency braking situation, depress
the brake pedal with full force. ABS prevents
the wheels from locking.
Braking
XKeep the brake pedal firmly depressed untilthe emergency braking situation is over.ABS prevents the wheels from locking.
The brakes will function as usual once yourelease the brake pedal. BAS is deactivated.
Active Brake Assist
General information
iObserve the "Important safety notes" sec-tion (Ypage 57).
Active Brake Assist consists of a distancewarning function with an autonomous brakingfunction and Adaptive Brake Assist.
Active Brake Assist can help you to minimizethe risk of a collision with the vehicle in frontor reduce the effects of such a collision.
If Active Brake Assist detects that there is arisk of collision, you will be warned visuallyand acoustically. If you do not react to the vis-ual collision warning or the warning tone,autonomous braking can be initiated in criticalsituations. If you apply the brake yourself in acritical situation, Adaptive Brake Assist of theActive Brake Assist system supports you.
Important safety notes
In particular, the detection of obstacles can beimpaired if:
Rthere is dirt on the sensors or anything elsecovering the sensors
Rthere is snow or heavy rain
Rthere is interference by other radar sources
Rthere are strong radar reflections, for exam-ple in parking garages
Ra narrow vehicle is traveling in front, e.g. amotorbike
Ra vehicle is traveling in front on a differentline
Ryou are driving a new vehicle or servicing onthe Active Brake Assist system has justbeen carried out
Observe the important safety notes in the"Breaking-in notes" section (Ypage 117).
Following damage to the front end of the vehi-cle, have the configuration and operation ofthe radar sensor checked at a qualified spe-cialist workshop. This also applies to collisionsat slow speeds where there is no visible dam-age to the front of the vehicle.
Activating/deactivating
Active Brake Assist is automatically activeafter switching on the ignition.
You can activate or deactivate Active BrakeAssist using the on-board computer(Ypage 175). When deactivated, the distancewarning function and the autonomous brakingfunction are also deactivated.
If Active Brake Assist is deactivated, the