2017 MERCEDES-BENZ S CLASS change key battery

KEYLESS- GO start function
Gene ra l notesBear in min d that th e engin e can be started by
any of th e vehicl e occupant s if there is a Smart -
Key in th e vehicl e ( Y
page 147).
Changing the settings of the locking
system You can chang e th e setting s of th e locking sys-
tem. This mean s that only th e driver's door and
th e fuel filler flap are unlocke d when th e vehicl e
is unlocked. This is useful if you frequentl y travel
on your own .X
To change th e setting: press and hold down
th e 6 and 7 buttons simultaneousl y
for approximately six seconds until th e bat -
tery chec k lamp ( Y
page 80 ) flashes twice .
If th e setting of th e locking system is changed
within th e signal range of th e vehicle, pressing
th e 7 or 6 button:R
locks or R
unlocks th e vehicl e
The SmartKey no w function s as follows :X
To unlock: press th e 6 butto n once .X
To unlock centrally: press th e 6 butto n
twice .X
To lock: press th e 7 button.
The KEYLESS-GO function s can be changed as
follows :X
To unlock th e driver's door : touch th e inner
surfac e of th e door handle on th e driver's
door .X
To unlock centrally: touch th e inner surfac e
of th e door handle on th e front-passenger
door or th e rear door .X
To lock centrally: touch th e outer sensor
surfac e on on e of th e door handles .X
To restor e th e factory settings: press and
hold th e 6 and 7 buttons simu ltane -
o
usl y for approximately six seconds until th e
battery chec k lamp ( Y
page 80) flashes
twice . Mechanical key
Gene ra l notesIf th e vehicl e can no longer be locke d or
unlocke d wit h th e SmartKey or KEYLESS-GO ,
use th e mechanical key.
If you use th e mechanical ke y to unloc k and
open th e driver's door , th e anti-thef t alarm sys-
te m will be triggered . Switc h off th e alarm
( Y
page 76) .
If you unloc k th e vehicl e usin g th e mechanical
key, th e fuel filler flap will no t be unlocke d auto -
matically. X
To unlock th e fuel filler flap: insert th e
SmartKey int o th e ignition lock.
Removing the me chanical key
X
Push release catch C in th e direction of th e
arrow and at th e sam e time remove mechan -
ical ke y D from th e SmartKey.
Fo r further information about :R
Locking/unlocking th e driver's door
( Y
page 84 ) R
Unlocking th e trunk ( Y
page 90 )
Inserting the me chanical key X
Push mechanical ke y D completely int o th e
SmartKey until it engage s and release
catch C is bac k in it s basic position .SmartKey 79
Opening and closing Z

SmartKey battery
Important safety notes
G WARNING
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.
H Environmental 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 perchlorate
material, which may require special handling
and regard for the environment. National guide-
lines must be observed during disposal. In Cal-
ifornia, see www.dtsc.ca.gov/
HazardousWaste/Perchlorate/index.cfm .
Mercedes-Benz recommends that you have the
batteries replaced at a qualified specialist work-
shop. Checking the battery X
Press the 7 or 6 button.
The battery is working properly if battery
check lamp C lights up briefly.
The battery is discharged if battery check
lamp C does not light up briefly. X
Change the battery ( Y
page 80).
If the SmartKey battery is checked within the
signal reception range of the vehicle, pressing
the 7 or 6 button: R
locks or R
unlocks the vehicle
i You can obtain a battery from any qualified
specialist workshop.
Replacing the battery You require a CR 2025 3 V cell battery. X
Take the mechanical key out of the SmartKey
( Y
page 79).
X
Press mechanical key D into the SmartKey
opening in the direction of the arrow until bat-
tery compartment cover C opens. Do not
hold battery compartment cover C closed
while doing so. X
Remove battery compartment cover C .80
SmartKey
Opening and closing

Problem
Possible causes/consequences and P Solutions
KEYLESS-GO is malfunctioning. X
Lock/unlock the vehicle using the remote control function of the
SmartKey. X
Have the vehicle and SmartKey checked at a qualified specialist
workshop.
If the vehicle can also not be locked/unlocked using the remote con-
trol function: X
Lock or unlock the vehicle using the mechanical key ( Y
page 84).X
Have the vehicle and SmartKey checked at a qualified specialist
workshop.
The engine cannot be
started using the Smart-
Key. The on-board voltage is too low. X
Switch off non-essential consumers, e.g. seat heating or interior
lighting, and try to start the engine again.
If this does not work: X
Check the starter battery and charge it if necessary ( Y
page 334).
or X
Jump-start the vehicle ( Y
page 335).
or X
Consult a qualified specialist workshop.
The engine cannot be
started using the Start/
Stop button. The Smart-
Key is in the vehicle. The vehicle is locked. X
Unlock the vehicle and try to start the vehicle again.
The SmartKey battery is discharged or nearly discharged. X
Check the SmartKey battery ( Y
page 80) and replace it if necessary
( Y
page 80).
If this does not work: X
Start your vehicle with the SmartKey in the ignition lock.
There is interference from a powerful source of radio waves. X
Start your vehicle with the SmartKey in the ignition lock.
You have lost a Smart-
Key. X
Have the SmartKey deactivated at a qualified specialist workshop. X
Report the loss immediately to the vehicle insurers. X
If necessary, have the locks changed as well.
You have lost the
mechanical key. X
Report the loss immediately to the vehicle insurers. X
If necessary, have the locks changed as well.82
SmartKey
Opening and closing

The battery must be connected and charged.
Otherwise, you: R
cannot turn the SmartKey to position 2 in the
ignition lock R
cannot release the electric parking brake R
cannot shift the automatic transmission to
position N
Disarm the automatic locking feature before the
vehicle is towed ( Y
page 84). You could other-
wise be locked out when pushing or towing the
vehicle.
If the vehicle is in a dangerous area, it can be
towed out of that area with both axles on the
ground. In this case, the towing distance must
not be greater than 165 ft (50 m) and must not
exceed a towing speed of 6 mph (10 km/h). For
longer distances, have the vehicle loaded and
transported.
Installing/removing the towing eye
Installing the towing eye
G WARNING
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 particular
care when removing the rear cover.
The brackets for the screw-in towing eye are
located in the bumpers. They are at the rear and
at the front, under covers C . X
Remove the towing eye from the vehicle tool
kit or the stowage tray ( Y
page 327).X
Press the mark on cover C inwards in the
direction of the arrow. X
Remove cover C from the opening.X
Screw in the towing eye clockwise as far as it
will go and tighten it.
Removing the towing eye X
Unscrew and remove the towing eye. X
Attach cover C to the bumper and press until
it engages. X
Place the towing eye in the vehicle tool kit or
the stowage tray.
Towing a vehicle with both axles on
the ground It is important that you observe the safety
instructions when towing away your vehicle
( Y
page 338).
The automatic transmission automatically shifts
to position P when you open the driver's or front-
passenger door or when you remove the Smart-
Key from the ignition lock.
In order to ensure that the automatic transmis-
sion stays in position N when towing the vehicle,
you must observe the following points: X
You must use the SmartKey instead of the
Start/Stop button ( Y
page 145).X
Make sure that the vehicle is stationary and
that the key is in position 0 in the ignition lock.X
Turn the SmartKey to position 2 in the ignition
lock. X
Depress and hold the brake pedal. X
Shift the automatic transmission to position
N . X
Release the brake pedal. X
Release the electric parking brake. X
Leave the SmartKey in position 2 in the igni-
tion lock. X
Switch on the hazard warning lamps
( Y
page 126).
In order to signal a change of direction when
towing the vehicle with the hazard warning
lamps switched on, use the combination switch
as usual. In this case, only the indicator lamps
for the direction of travel flash. After resettingTowing and tow-starting 339
Breakdown assistance Z