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.
An electric motor is used by PRE-SAFE®to trig-ger the tightening of the seat belt in hazardoussituations. 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. The urestraint 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 44)
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 and driver's knee bag
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 44).
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-sive role in the deployment of an air bag. Nor do
56Occupant safety
Safety
Driving safety systems
Overview of driving safety systems
In this section, you will find information aboutthe following driving safety systems:
RABS (Anti-lockBrakingSystem)(Ypage 65)
RBAS (BrakeAssistSystem) (Ypage 66)
RActive Brake Assist (Ypage 66)
RESP®(ElectronicStabilityProgram)(Ypage 68)
REBD (ElectronicBrake forceDistribution)(Ypage 72)
RADAPTIVE BRAKE (Ypage 72)
RActive Brake Assist with cross-traffic function(Ypage 72)
RSTEER CONTROL (Ypage 75)
Important safety notes
If you fail to adapt your driving style or if you areinattentive, the driving safety systems can nei-ther reduce the risk of an accident nor overridethe laws of physics. Driving safety systems aremerely aids designed to assist driving. You areresponsible for maintaining the distance to thevehicle in front, for vehicle speed, for braking ingood time, and for staying in lane. Always adaptyour driving style to suit the prevailing road andweather conditions and maintain a safe distancefrom the vehicle in front. Drive carefully.
The driving safety systems described only workas effectively as possible when there is ade-quate contact between the tires and the roadsurface. Pay particular attention to the informa-tion regarding tires, recommended minimumtire tread depths etc. in the "Wheels and tires"section (Ypage 330).
In wintry driving conditions, always use wintertires (M+S tires)and if necessary, snow chains.Only in this way will the driving safety systemsdescribed in this section work as effectively aspossible.
ABS (Anti-lock Braking System)
General information
ABS regulates brake pressure in such a way thatthe wheels do not lock when you brake. Thisallows you to continue steering the vehicle whenbraking.
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 conditions.ABS works on slippery surfaces, even when youonly brake gently.
Important safety notes
iObserve the "Important safety notes" sec-tion (Ypage 65).
GWARNING
If ABS is faulty, the wheels could lock when
braking. The steerability and braking charac-
teristics may be severely impaired. Addition-
ally, further driving safety systems are deac-
tivated. There is an increased danger of skid-
ding 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 259) and dis-play messages which may be shown in theinstrument cluster (Ypage 228).
Braking
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 as areminder to take extra care while driving.
Driving safety systems65
Safety
Z
multimedia system; see the Digital Operator'sManual.
You will receive visual and acoustic locking con-firmation if all components were able to belocked.
When the locator lighting is activated via themultimedia system, it lights up when it is darkafter the vehicle is unlocked with the SmartKey;see the Digital Operator's Manual.
XTo open the tailgate automatically fromoutside the vehicle:press and hold the Tbutton until the tailgate opens.
XTo close the tailgate automatically fromoutside the vehicle:if the SmartKey is loca-ted in the immediate vicinity of the vehicle,press the Tbutton on the SmartKey.When the tailgate closes you can then releasethe button.
KEYLESS-GO
General notes
Bear in mind that the engine can be started byany of the vehicle occupants if there is a Smart-Key in the vehicle (Ypage 133).
Locking/unlocking centrally
You can start, lock or unlock the vehicle usingKEYLESS-GO. To do this, you only need carry theSmartKey with you. You can combine the func-tions of KEYLESS-GO with those of a conven-tional SmartKey. Unlock the vehicle by usingKEYLESS-GO, for instance, and lock it using the 7button on the SmartKey.
The driver's door and the door at which the han-dle is used, must both be closed. The SmartKeymust be outside the vehicle. When locking orunlocking with KEYLESS-GO, the distancebetween the SmartKey and the correspondingdoor handle must not be greater than 3 ft (1 m).
A brief radio connection between the vehicleand the SmartKey determines whether a validSmartKey is in, or in the direct vicinity of, thevehicle. This occurs, for example:
Rwhen starting the engine
Rwhile driving
Rwhen using HANDS-FREE ACCESS
Rwhen the external door handles are touched
Rduring convenience closing
XTo unlock the vehicle:touch the inner sur-face of the door handle.
XTo lock the vehicle:touch sensor surface Cor D.
Make sure that you do not touch the innersurface of the door handle.
XConvenience closing feature:touchrecessed sensor surface Dfor an extendedperiod.
Further information on the convenience clos-ing feature (Ypage 91).
XTo unlock the tailgate:push the top of staron the tailgate.
Deactivating and activating
If you do not intend to use a SmartKey for anextended period of time, you can deactivate theKEYLESS-GO function of the SmartKey. TheSmartKey will then use very little power, therebyconserving battery power. For the purposes ofactivation/deactivation, the vehicle must not benearby.
XTo deactivate:press the 7button on theSmartKey twice in rapid succession.The battery check lamp (Ypage 80) of theSmartKey flashes twice briefly and lights uponce, then KEYLESS-GO is deactivated.
XTo activate:press any button on the Smart-Key.
or
XInsert the SmartKey into the ignition lock.KEYLESS-GO and all of its associated featuresare available again.
78SmartKey
Opening and closing
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.
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.
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 thebatteries replaced at a qualified specialist work-shop.
Checking the battery
XPress the 7or 6button.The battery is working properly if batterycheck lamp Clights up briefly.
The battery is discharged if battery checklamp Cdoes not light up briefly.
XChange the battery (Ypage 80).
If the SmartKey battery is checked within thesignal reception range of the vehicle, pressingthe 7or 6button:
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 79).
XPress mechanical key Dinto the SmartKeyopening in the direction of the arrow until bat-tery compartment cover Copens. Do nothold battery compartment cover Cclosedwhile doing so.
XRemove battery compartment cover C.
80SmartKey
Opening and closing
Exterior lighting
General notes
USA only: if you wish to drive during the daytimewithout lights, switch off theDaytime Run‐Daytime Run‐ning Lightsning Lightsfunction via the on-board com-puter (Ypage 222).
Setting the exterior lighting
Setting options
Exterior lighting can be set using the:
Rlight switch (Ypage 109)
Rcombination switch (Ypage 110)
Ron-board computer (Ypage 222)
Light switch
Operation
G cLeft-hand standing lamps
H dRight-hand standing lamps
I `Parking lamps, license plate andinstrument cluster lighting
J XAutomatic headlamp mode, controlledby the light sensor
K XLow-beam/high-beam headlamps