2016 MERCEDES-BENZ S CLASS change key battery

conserving battery power. For the purposes of
activation/deactivation, the vehicle must not be
nearby. X
To deactivate: press the 7 button on the
SmartKey twice in rapid succession.
The battery check lamp ( Y
page 82) of the
SmartKey flashes twice briefly and lights up
once, then KEYLESS-GO is deactivated . X
To activate: press any button on the Smart-
Key.
or X
Insert the SmartKey into the ignition lock.
KEYLESS-GO and all of its associated features
are available again.
KEYLESS-GO start function
General notes Bear in mind that the engine can be started by
any of the vehicle occupants if there is a Smart-
Key in the vehicle ( Y
page 164).
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 and
the fuel filler flap are unlocked when the vehicle
is unlocked. This is useful if you frequently travel
on your own. X
To change the setting: press and hold down
the 6 and 7 buttons simultaneously
for approximately six seconds until the bat-
tery check lamp flashes twice ( Y
page 82).
If the setting of the locking system is changed
within the signal range of the vehicle, pressing
the 7 or 6 button:R
locks or R
unlocks the vehicle
The SmartKey now functions as follows: X
To unlock: press the 6 button once.X
To unlock centrally: press the 6 button
twice. X
To lock: press the 7 button. The KEYLESS-GO function is changed as fol-
lows: X
To unlock the driver's door: touch the inner
surface of the door handle on the driver's
door. X
To unlock centrally: touch the inner surface
of the door handle on the front-passenger
door or the rear door. X
To lock centrally: touch the outer sensor
surface on one of the door handles. X
To restore the factory settings: press and
hold the 6 and 7 buttons simultane-
ously for approximately six seconds until the
battery check lamp flashes twice
( Y
page 82).
Mechanical key
General notes If the vehicle can no longer be locked or
unlocked with the SmartKey or KEYLESS-GO,
use the mechanical key.
If you use the mechanical key to unlock and
open the driver's door, the anti-theft alarm sys-
tem will be triggered. Switch off the alarm
( Y
page 78).
If you unlock the vehicle using the mechanical
key, the fuel filler flap will not be unlocked auto-
matically. X
To unlock the fuel filler flap: insert the
SmartKey into the ignition lock.
Removing the mechanical key
X
Push release catch C in the direction of the
arrow and at the same time remove mechan-
ical key D from the SmartKey.SmartKey 81
Opening and closing Z

For further information about: R
unlocking the driver's door ( Y
page 87)R
unlocking the trunk ( Y
page 93)R
locking the vehicle ( Y
page 88)
Inserting the mechanical key X
Push mechanical key D completely into the
SmartKey until it engages and release
catch C is back in its basic position.
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 82).
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 81).
X
Press mechanical key D into the SmartKey
opening in the direction of the arrow until bat-82
SmartKey
Opening and closing

Problem
Possible causes/consequences and P Solutions
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 374).
or X
Jump-start the vehicle ( Y
page 376).
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 82) and replace it if necessary
( Y
page 82).
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.
Doors
Important safety notes
G WARNING
If children are left unsupervised in the vehicle,
they could: R
open the doors, thus endangering other
people or road users. R
get out and disrupt traffic. R
operate the vehicle's equipment. Additionally, children could set the vehicle in
motion if, for example, they: R
release the parking brake. R
shifting the automatic transmission out of
park position P R
Start the engine.
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 or animals unattended in the
vehicle. Always keep the SmartKey out of
reach of children. Doors 85
Opening and closing Z

Hybrid drive system Display messages
Possible causes/consequences and P Solutions
r Vehicle Operational
Switch the Ignition
Off Before Exiting PLUG-IN HYBRID vehicles:
You are leaving the vehicle when it is in a ready-to-drive state. The
READY indicator in the multifunction display is on. A warning tone also
sounds.
If you leave the vehicle: X
Secure the vehicle against rolling away ( Y
page 189).X
Switch off the ignition and remove the SmartKey.
If you do not leave the vehicle: X
Switch off the electrical consumers, e.g. automatic climate control,
seat heating.
Please note the following: the electrical consumers are supplied by the
12 V battery. If the vehicle is left in a ready-to-drive state for an exten-
ded period, it will switch off once the 12 V battery is almost empty. It
will then only be possible to start the vehicle using a second battery
(jump-starting).
Change the current
drive program
before changing the
operating mode. or
Exit manual drive
program M before
changing the operat‐
ing mode. PLUG-IN HYBRID vehicles:
You have attempted to change the operating mode when in automatic
drive program S (Sport) or manual drive program M .X
Activate the drive program E (Economy) or E+ (Economy Plus)
( Y
page 250). X
Select the preferred operating mode HYBRID , E-MODE , E-SAVE or
CHARGE ( Y
page 243).
E-MODE Currently
Unavailable PLUG-IN HYBRID vehicles:
The condition of charge of the high-voltage battery has dropped to the
lower limit and the E-MODE operating mode has been switched off.
Driving with the internal combustion engine is activated and the oper-
ating mode switches to the basic HYBRID setting.X
Continue driving using the internal combustion engine.
You can switch to the E-SAVE or CHARGE operating mode as
required ( Y
page 243).
If you select CHARGE , the high-voltage battery is charged.
Once the charge level display for the high-voltage battery has
increased slightly, you can switch to the E-MODE operating mode
again. Display messages 297
On-board computer and displays Z