2019 MERCEDES-BENZ CLA change key battery

Changing the settings of the locking
system
You can change the settings of the locking sys-tem. This means that only the driver's door andthe fuel filler flap are unlocked when the vehicleis unlocked. This is useful if you frequently travelon your own.
XTo change the setting:press and hold the6and7buttons simultaneously forapproximately six seconds until the batteryindicator lamp flashes twice (Ypage 73).
If the setting of the locking system is changedwithin the signal range of the vehicle, pressingthe7or6button:
Rlocks or
Runlocks the vehicle
The SmartKey now functions as follows:
XTo unlock:press the6button once.
XTo unlock centrally:press the6buttontwice.
XTo lock centrally:press the7button.
The KEYLESS-GO function is changed as fol-lows:
XTo unlock the driver's door:touch the innersurface of the door handle on the driver'sdoor.
XTo unlock centrally:touch the inner surfaceof the door handle on the front-passengerdoor or the rear door.
XTo lock centrally:touch the outer sensorsurface on one of the door handles.
XTo restore the factory settings:press andhold the6and7buttons simultane-ously for approximately six seconds until thebattery check lamp flashes twice(Ypage 73).
Mechanical key
General notes
If the vehicle can no longer be locked orunlocked with the SmartKey or KEYLESS-GO,use the mechanical key.
If you use the mechanical key to unlock andopen the driver's door or the trunk lid, the anti-theft alarm system will be triggered (Ypage 68).
There are several ways to turn off the alarm:
XTo deactivate the alarm with the key:pressthe6or7button on the key.
or
XInsert the SmartKey into the ignition lock.
or
XTo deactivate the alarm with KEYLESS-GO:press the Start/Stop button in the ignitionlock. The SmartKey must be in the vehicle.
or
XLock or unlock the vehicle using KEYLESS-GO. The SmartKey must be outside the vehi-cle.
If you unlock the vehicle using the mechanicalkey, the fuel filler flap will not be unlocked auto-matically.
XTo unlock the fuel filler flap:insert theSmartKey into the ignition lock.
Removing the mechanical key
XPush release catchCin the direction of thearrow and at the same time remove mechan-ical keyDfrom the SmartKey.
For further information about:
RUnlocking the driver's door (Ypage 77)
RUnlocking the trunk (Ypage 82)
RLocking the vehicle (Ypage 77)
Inserting the mechanical key
XPush mechanical keyDcompletely into theSmartKey until it engages and releasecatchCis back in its basic position.
72SmartKey
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.
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

ProblemPossible causes/consequences andPPSolutions
KEYLESS-GO is malfunctioning.
XLock/unlock the vehicle using the remote control function of theSmartKey.
XHave the vehicle and SmartKey checked at a qualified specialistworkshop.
If the vehicle can also not be locked/unlocked using the remote con-trol function:
XUnlock (Ypage 77) or lock (Ypage 77) the vehicle using themechanical key.
XHave the vehicle and SmartKey checked at a qualified specialistworkshop.
The engine cannot bestarted using the Smart-Key.
The on-board voltage is too low
XSwitch off non-essential consumers, e.g. seat heating or interiorlighting, and try to start the engine again.
If this does not work:
XCheck the starter battery and charge it if necessary (Ypage 281).
or
XJump-start the vehicle (Ypage 282).
or
XConsult a qualified specialist workshop.
The engine cannot bestarted using the Start/Stop button. The Smart-Key is in the vehicle.
The vehicle is locked.
XUnlock the vehicle and try to start the vehicle again.
The SmartKey battery is discharged or nearly discharged.
XCheck the SmartKey battery (Ypage 73) and replace it if necessary(Ypage 73).
If this does not work:
XStart your vehicle with the SmartKey in the ignition lock.
There is interference from a powerful source of radio waves.
XStart your vehicle with the SmartKey in the ignition lock.
You have lost a Smart-Key.XHave the SmartKey deactivated at a qualified specialist workshop.
XReport the loss immediately to the vehicle insurers.
XIf necessary, have the locks changed as well.
You have lost themechanical key.XReport the loss immediately to the vehicle insurers.
XIf necessary, have the locks changed as well.
SmartKey75
Opening and closing
Z

The three red indicator lamps in the button indi-cate the heating level you have selected.
The system automatically switches down fromlevel3to level2after approximately eightminutes.
The system automatically switches down fromlevel2to level1after approximately tenminutes.
The system automatically switches off approx-imately 20 minutes after it is set to level1.
XTurn the SmartKey to positionGorHin theignition lock (Ypage 123).
XTo switch on:press buttonCrepeatedlyuntil the desired heating level is set.
XTo switch off:press buttonCrepeatedlyuntil all the indicator lamps go out.
iIf the battery voltage is too low, the seatheating may switch off.
Problems with the seat heating
ProblemPossible causes/consequences andPPSolutions
The seat heating hasswitched off prematurelyor cannot be switchedon.
The on-board voltage is too low because too many electrical consum-ers are switched on.
XSwitch off electrical consumers that you do not need, such as therear window defroster or interior lighting.Once the battery is sufficiently charged, the seat heating will switchback on automatically.
Steering wheel
Important safety notes
GWARNING
You could lose control of your vehicle if you do
the following while driving:
Radjust the driver's seat, head restraint,
steering wheel or mirrors
Rfasten the seat belt
There is a risk of an accident.
Adjust the driver's seat, head restraint, steer-
ing wheel and mirror and fasten your seat belt
before starting the engine.
GWARNING
Children could injure themselves if they
adjust the steering wheel. There is a risk of
injury.
Never leave children unsupervised in the vehi-
cle.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. This
also applies for the Digital Vehicle Key if the
"Digital Vehicle Key" function is activated via
Mercedes me connect.
Adjusting the steering wheel
GWARNING
If the steering wheel is unlocked while the
vehicle is in motion, it could change position
unexpectedly. This could cause you to lose
control of the vehicle. There is a risk of an
accident.
96Steering wheel
Seats, steering wheel and mirrors

GWARNING
Flammable materials introduced through
environmental influence or by animals can
ignite if in contact with the exhaust system or
parts of the engine that heat up. There is a risk
of fire.
Carry out regular checks to make sure that
there are no flammable foreign materials in
the engine compartment or in the exhaust
system.
General notes
During a cold start, the engine runs at higherspeeds to enable the catalytic converter toreach its operating temperature. The sound ofthe engine may change during this time.
Automatic transmission
XShift the transmission to position](Ypage 132).The transmission position indicator on themultifunction display shows](Ypage 131).
iYou can start the engine in transmissionpositions]and\\.
Starting procedure with the SmartKey
To start the engine using the SmartKey insteadof the Start/Stop button, pull the Start/Stopbutton out of the ignition lock.
XTurn the SmartKey to positionIin the igni-tion lock (Ypage 123) and release it as soonas the engine is running.
Starting procedure with the Start/Stop
button
The Start/Stop button can be used to start thevehicle manually without inserting the SmartKeyinto the ignition lock. The Start/Stop buttonmust be inserted in the ignition lock and theSmartKey must be in the vehicle. This mode forstarting the engine operates independently ofthe ECO start/stop automatic engine start func-tion.
You can start the engine if a valid SmartKey is inthe vehicle. Switch off the engine and alwaystake the SmartKey with you when leaving the
vehicle, even if you only leave it for a short time.Pay attention to the important safety notes.
XDepress the brake pedal and keep itdepressed.
XPress the Start/Stop button once(Ypage 123).The engine starts.
Starting procedure via smartphone
Observe the important safety notes on startingthe engine (Ypage 124).
You can also start your engine via your smart-phone from outside the vehicle. In this case, thepreviously selected climate control setting isactivated. In this way you can cool or heat theinterior of the vehicle before starting the jour-ney.
Only start the engine via your smartphone if it issafe to start and run the engine where your vehi-cle is parked.
Observe the legal stipulations in the area whereyour vehicle is parked. Engine start via smart-phone may be limited to certain countries orregions.
You can execute a maximum of two consecutivestarting attempts via your smartphone. If youinsert the SmartKey into the ignition lock, youcan carry out two more starting attempts.
Once you have started the engine, you canswitch the engine off via your smartphone at anytime.
You can only start the engine via your smart-phone if:
Rthe SmartKey is in the ignition lock
Rpark position]is selected
Rthe accelerator pedal is not depressed
Rthe alarm for the anti-theft alarm system isnot set
Rthe panic alarm is not activated
Rthe hazard warning lamps are switched off
Rthe hood is closed
Rthe doors are closed and locked
Rthe windows and sliding sunroof are closed
Also make sure that:
Rthe fuel tank is sufficiently filled
Rthe starter battery has been sufficientlycharged
Driving125
Driving and parking
Z

ProblemPossible causes/consequences andPPSolutions
The engine does notstart. You cannot hearthe starter motor.
The on-board voltage is too low because the battery is too weak ordischarged.
XJump-start the vehicle (Ypage 282).
If the engine does not start despite attempts to jump-start it:
XConsult a qualified specialist workshop.
The starter motor was exposed to a thermal load that was too high.
XAllow the starter motor to cool down for approximately two minutes.
XTry to start the engine again.
If the engine still does not start:
XConsult a qualified specialist workshop.
The engine is not runningsmoothly and is misfir-ing.
There is a malfunction in the engine electronics or in a mechanicalcomponent of the engine management system.
XOnly depress the accelerator pedal slightly.Otherwise, non-combusted fuel may get into the catalytic converterand damage it.
XHave the cause rectified immediately at a qualified specialist work-shop.
The coolant temperaturegauge shows a valueabove 248 ‡ (120 †).The coolant warninglamp may also be on anda warning tone maysound.
The coolant level is too low. The coolant is too hot and the engine is nolonger being cooled sufficiently.
XStop as soon as possible and allow the engine and the coolant tocool down.
XCheck the coolant level (Ypage 263). Observe the warning notesas you do so and add coolant if necessary.
Notes on towing vehicles
The vehicle is not suitable for attaching tow barsystems, such as those used for flat towing ordinghy towing.
Attaching or using tow bar systems may result indamage to the vehicle.
When towing a vehicle with tow bar systems,safe driving characteristics cannot be guaran-teed for the towing vehicle or the towed vehicle.
The vehicle/trailer combination may swerve.
Observe the permissible towing methods(Ypage 287) and the notes on towing with bothaxles on the ground (Ypage 286).
DYNAMIC SELECT button (all vehicles
except Mercedes-AMG vehicles)
Use the DYNAMIC SELECT button to change thedrive program. Depending on the drive programselected the following vehicle characteristicswill change:
Rthe drive (engine and transmission manage-ment)
Rthe suspension (vehicles with damping sys-tem or AMG adaptive sport suspension sys-tem)
Rthe sound of the exhaust system (vehicleswith sports exhaust system)
Rthe steering
Rthe availability of the ECO start/stop function
Rthe climate control
Each time you start the engine with the Smart-Key or the Start/Stop button, drive programCis
DYNAMIC SELECT button (all vehicles except Mercedes-AMG vehicles)129
Driving and parking
Z