Index MERCEDES-BENZ CLA 2019 Owner's Manual

and to have any malfunctioning air bagsrepaired. This will help to make sure the air bagscontinue to perform their protective function forthe vehicle occupants in the event of a crash.
GWARNING
Emergency Tensioning Devices that have
deployed pyrotechnically are no longer opera-
tional and are unable to perform their inten-
ded 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.
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 your hear-ing. The powder that is released generally doesnot constitute a health hazard, but it may causeshort-term breathing difficulties in people withasthma or other respiratory problems. Providedit is safe to do so, you should leave the vehicleimmediately or open the window in order to pre-vent breathing difficulties.
Air bags and pyrotechnic Emergency TensioningDevices (ETDs) contain perchlorate material,which may require special handling and regardfor the environment. National guidelines mustbe observed during disposal. In California, seewww.dtsc.ca.gov/HazardousWaste/Perchlorate/index.cfm.
Method of operation
During the first stage of a collision, the restraintsystem control unit evaluates important physi-cal data relating to vehicle deceleration or accel-eration, 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 41)
Rthe seat belt buckle tongue has engaged inthe belt buckle of the respective front seat
The Emergency Tensioning Devices in the rearpassenger compartment are triggered inde-pendently of the lock status of the seat belts.
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
RWindow curtain air bag, if the system deter-mines that deployment can offer additionalprotection to that provided by the seat belt
Depending on the person in the front-passengerseat, the front-passenger front air bag is eitherdisabled or enabled. The front-passenger frontair bag can be deployed in an accident only if thePASSENGER AIR BAG OFF indicator lamp is off.Observe the information on the PASSENGER AIRBAG indicator lamps (Ypage 41).
Your vehicle has two-stage front air bags. At thefirst deployment threshold the front air bag fillswith gas. If the second deployment threshold isthen reached within a few milliseconds, the frontair bag is filled with the maximum quantity ofgas.
The activation threshold of the Emergency Ten-sioning Devices and the air bags is determinedby evaluating the rate of vehicle deceleration oracceleration which occurs at various points inthe vehicle. This process is pre-emptive innature. Deployment should take place in goodtime at the start of the collision.
The rate of vehicle deceleration or accelerationand the direction of the force are essentiallydetermined by:
Rthe distribution of forces during the collision
Rthe collision angle
Rthe deformation characteristics of the vehicle
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 a deci-
Occupant safety53
Safety
Z

SmartKey battery
Important safety notes
GWARNING
Batteries contain toxic and corrosive substan-
ces. If batteries are swallowed, it can result in
severe health problems. There is a risk of fatal
injury.
Keep batteries out of the reach of children. If
a battery is swallowed, seek medical attention
immediately.
The SmartKey batteries contain perchloratematerial, which may require special handlingand regard for the environment. National guide-lines must be observed during disposal. In Cal-ifornia, seewww.dtsc.ca.gov/HazardousWaste/Perchlorate/index.cfm.
Mercedes-Benz recommends that you have thebattery replaced at a qualified specialist work-shop.
Checking the battery
XPress the7or6button.The battery is working properly if batterycheck lampClights up briefly.
The battery is discharged if battery checklampCdoes not light up briefly.
XChange the battery (Ypage 73).
iIf the SmartKey battery is checked withinthe signal reception range of the vehicle,pressing the7or6button:
Rlocks or
Runlocks the vehicle
iYou can get a battery at any qualified spe-cialist workshop.
Replacing the battery
You require a CR 2025 3 V cell battery.
XTake the mechanical key out of the SmartKey(Ypage 72).
XPress mechanical keyDinto the opening inthe SmartKey in the direction of the arrowuntil battery tray coverCopens. When doingso, do not hold coverCshut.
XRemove battery tray coverC.
XRepeatedly tap the SmartKey against yourpalm until battery

XMake sure that the engine cannot be startedvia your smartphone (Ypage 124).
XMake sure that the passengers are not endan-gered as they do so. Make sure that no one isnear the danger area while a wheel is beingchanged. Anyone who is not directly assistingin the wheel change should, for example,stand behind the barrier.
XGet out of the vehicle. Pay attention to trafficconditions when doing so.
XClose the driver's door.
MOExtended tires (tires with run-flat
properties)
General notes
With MOExtended tires (tires with run flat char-acteristics), you can continue to drive your vehi-cle even if there is a total loss of pressure in oneor more tires. The affected tire must not showany clearly visible damage.
You can recognize a MOExtended tire by theMOExtended marking which appears on thesidewall of the tire. You will find this markingnext to the tire size designation, the load-bear-ing capacity and the speed index (Ypage 305).
MOExtended tires may be used only in conjunc-tion with an activated tire pressure loss warningsystem (Canada only) or tire pressure monitor(USA only).
If a pressure loss warning message appearsin the multifunction display:
Robserve the instructions in the display mes-sages (Ypage 213).
Rcheck the tire for damage
Rif driving on, observe the following notes
The driving distance possible in run-flat mode isapproximately 50 miles (80 km) when the vehi-cle is partially laden. When the vehicle is fullyladen it is approximately 19 miles (30 km).
In addition to the vehicle load, the driving dis-tance possible depends upon:
Rvehicle speed
Rroad condition
Routside temperature
The driving distance possible in run-flat modemay be reduced by extreme driving conditionsor maneuvers, or it can be increased through amoderate style of driving.
The driving distance possible in run-flat mode iscounted from the moment the tire pressure losswarning appears in the multifunction display.
You must not exceed a maximum speed of50 mph (80 km/h).
When replacing one or all tires, please observethe following specifications for your vehicle'stires:
Rsize
Rtype and
Rthe "MOExtended" marking
If a tire has gone flat and cannot be replacedwith a MOExtended tire, a standard tire may beused as a temporary measure. Make sure thatyou use the proper size and type (summer orwinter tire).
Vehicles equipped with MOExtended tires arenot equipped with a TIREFIT kit at the factory. Itis therefore recommended that you additionallyequip your vehicle with a TIREFIT kit if you mounttires that do not feature run-flat properties, e.g.winter tires. A TIREFIT kit may be obtained froma qualified specialist workshop.
Important safety notes
GWARNING
When driving in emergency mode, the driving
characteristics deteriorate, e.g. when corner-
ing, accelerating quickly and when braking.
There is a risk of an accident.
Do not exceed the stated maximum speed.
Avoid abrupt steering and driving maneuvers,
and driving over obstacles (curbs, potholes,
off-road). This applies in particular to a laden
vehicle.
Stop driving in emergency mode if:
Ryou hear banging noises.
Rthe vehicle starts to shake.
Ryou see smoke and smell rubber.
RESP®is intervening constantly.
Rthere are tears in the sidewalls of the tire.
After driving in emergency mode, have the
wheel rims checked at a qualified specialist
workshop with regard to their further use. The
defective tire must be replaced in every case.
Flat tire275
Breakdown assistance
Z

the size description, depending on the man-ufacturer (e.g. 245/40 ZR18).
The service specification is made up of load-bearing index

Uniform Tire Quality Grading Standards
A uniform standard to grade the quality of tireswith regards to tread quality, tire traction andtemperature characteristics. The quality grad-ing assessment is made by the manufacturerfollowing specifications from the U.S. govern-ment. The ratings are molded into the sidewall ofthe tire.
Recommended tire pressures
The recommended tire pressure applies to thetires mounted at the factory.
The Tire and Loading Information placard con-tains the recommended tire pressures for coldtires on a fully loaded vehicle and for the maxi-mum permissible vehicle speed.
The tire pressure table contains the recommen-ded pressures for cold tires for various operat-ing conditions, i.e. differing load and speed con-ditions.
Increased vehicle weight due to optional
equipment
The combined weight of all standard andoptional equipment available for the vehicle,regardless of whether it is actually installed onthe vehicle or not.
Rim
This is the part of the wheel on which the tire ismounted.
GAWR (Gross Axle Weight Rating)
The GAWR is the maximum gross axle weightrating. The actual load on an axle must neverexceed the gross axle weight rating. The grossaxle weight rating can be found on the vehicleidentification plate on the B-pillar on the driver'sside.
Speed rating
The speed rating is part of the tire identification.It specifies the speed range for which the tire isapproved.
GVW (Gross Vehicle Weight)
The gross vehicle weight includes the weight ofthe vehicle including fuel, tools, the spare wheel,accessories installed, occupants, luggage andthe drawbar noseweight, if applicable. The grossvehicle weight must not exceed the gross vehi-cle weight rating GVWR as specified on the vehi-cle identification plate on the B-pillar on thedriver's side.
GVWR (Gross Vehicle Weight Rating)
The GVWR is the maximum permissible grossweight of a fully loaded vehicle (the weight of thevehicle including all accessories, occupants,fuel, luggage and the drawbar noseweight, ifapplicable). The gross vehicle weight rating isspecified on the vehicle identification plate onthe B-pillar on the driver's side.
Maximum loaded vehicle weight
The maximum weight is the sum of:
Rthe curb weight of the vehicle
Rthe weight of the accessories
Rthe load limit
Rthe weight of the factory installed optionalequipment
Kilopascal (kPa)
Metric unit for tire pressure. 6.9 kPa corre-sponds to 1 psi. Another unit for tire pressure isbar. 100 kilopascals (kPa) are the equivalent of1 bar.
Load index
In addition to the load-bearing index, the loadindex may also be imprinted on the sidewall ofthe tire. This specifies the load-bearing capacitymore precisely.
Curb weight
The weight of a vehicle with standard equipmentincluding the maximum capacity of fuel, oil andcoolant. 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 isapproved.
Maximum permissible tire pressure
Maximum permissible tire pressure for one tire.
Maximum load on one tire
Maximum load on one tire. This is calculated bydividing the maximum axle load of one axle bytwo.
All about wheels and tires309
Wheels and tires
Z

PSI (pounds per square inch)
A standard unit of measure for tire pressure.
Aspect ratio
Relationship between tire height and tire widthin percent.
Tire pressure
This is pressure inside the tire applying an out-ward force to each square inch of the tire's sur-face. The tire pressure is specified in pounds persquare inch (psi), in kilopascal (kPa) or in bar.The tire pressure should only be corrected whenthe tires are cold.
Cold tire pressure
The tires are cold:
Rif the vehicle has been parked with the tiresout of direct sunlight for at least three hoursand
Rif the vehicle has not been driven further than1 mile (1.6 km)
Tread
The part of the tire that comes into contact withthe road.
Bead
The tire bead ensures that the tire sits securelyon the wheel. There are several steel wires in thebead to prevent the tire from coming loose fromthe wheel rim.
Sidewall
The part of the tire between the tread and thebead.
Weight of optional extras
The combined weight of those optional extrasthat weigh more than the replaced standardparts and more than 2.3 kg (5 lbs). Theseoptional extras, such as high-performancebrakes, level control, a roof rack or a high-per-formance battery, are not included in the curbweight and the weight of the accessories.
TIN (Tire Identification Number)
This is a unique identifier which can be used bya tire manufacturer to identify tires, for examplefor a product recall, and thus identify the pur-chasers. The TIN is made up of the manufactur-er's identity code, tire size, tire type code andthe manufacturing date.
Load bearing index
The load bearing index (also load index) is a codethat contains the maximum load bearing capa-city of a tire.
Traction
Traction is the result of friction between the tiresand the road surface.
Treadwear indicators
Narrow bars (tread wear bars) that are distrib-uted over the tire tread. If the tire tread is levelwith the bars, the wear limit of