2017 MERCEDES-BENZ S CLASS ECU

Child-proof locks for the rear doors
You secure each door individually with the child-
proof locks on the rear doors. A door secured
with a child-proof lock cannot be opened from
inside the vehicle. When the vehicle is unlocked,
the door can be opened from the outside. X
To activate: press the child-proof lock lever
up in the direction of arrow C .X
Make sure that the child-proof locks are work-
ing properly. X
To deactivate: press the child-proof lock
lever down in the direction of arrow D .
Override feature for the rear side win-
dows
X
To activate/deactivate: press button D .
If indicator lamp C is lit, operation of the rear
side windows is disabled. Operation is only
possible using the switches in the driver's
door. If indicator lamp C is off, operation is
possible using the switches in the rear com-
partment. When the override feature is activated, the con-
trols in the rear compartment are disabled for: R
the rear side windows R
adjustment of the front-passenger seat from
the rear compartment R
the sunblinds: -
of the rear side windows -
of the rear window -
in the roof
Pets in the vehicle
G WARNING
If you leave animals unattended or unsecured
in the vehicle, they could press buttons or
switches, for example.
As a result, they could: R
activate vehicle equipment and become
trapped, for example R
activate or deactivate systems, thereby
endangering other road users
Unsecured animals could also be flung around
the vehicle in the event of an accident or sud-
den steering or braking, thereby injuring vehi-
cle occupants. There is a risk of an accident
and injury.
Never leave animals unattended in the vehi-
cle. Always secure animals properly during
the journey, e.g. use a suitable animal trans-
port box.
Driving safety systems
Overview of driving safety systems In this section, you will find information about
the following driving safety systems: R
ABS ( A nti-lock B raking S ystem)
( Y
page 66) R
BAS ( B rake A ssist S ystem) ( Y
page 66)R
BAS PLUS ( B rake A ssist S ystem PLUS) with
Cross-Traffic Assist ( Y
page 67)R
COLLISION PREVENTION ASSIST PLUS
( Y
page 68)Driving safety systems 65
Safety Z

Door s
Important safet y notes
G WARNING
If children are lef t unsupervised in th e vehicle,
they could: R
ope n th e doors , thus endangerin g other
people or road users. R
get out and disrup t traffic .R
operat e th e vehicle' s equipment.
Additionally, children could set th e vehicle in
motion if, fo r example, they:R
release th e parking brake .R
shiftin g th e automatic transmissio n out of
par k position PR
Start th e engine.
There is a ris k of an acciden t and injury.
Whe n leavin g th e vehicle, always take th e
SmartKey wit h you and loc k th e vehicle. Never
leav e children or animals unattended in th e
vehicle. Always keep th e SmartKey out of
reach of children .
Unlockin g an d opening doors from
th e insideYou can ope n a doo r from insid e th e vehicle
eve n if it has bee n locked. You can only ope n th e
rea r doors from insid e th e vehicle if they are no t
secure d by th e child-proof locks ( Y
page 65). If
th e vehicle has bee n locke d wit h th e SmartKey
or wit h KEYLESS-GO , opening a doo r from th e
insid e will trigger th e anti-thef t alar m system.
Switc h of f th e alar m ( Y
page 76) . X
To unlock an d ope n a front door: pull doo r
handle D .
If th e doo r is locked, locking knob C pop s up.
The doo r is unlocke d and opens .X
To unlock a rear door: pull rea r doo r handle.
The locking knob on th e rea r doo r pop s up and
th e rea r doo r unlocks .X
To ope n a rear door: pull rea r doo r handle
again .
The rea r doo r opens .
Centrally locking an d unlocking th e
vehicle from th e insideYou can centrall y loc k and unloc k th e vehicle
from th e inside. The buttons are located on bot h
fron t doors .
X
To unlock : press butto n C .X
To lock : press butto n D .
If th e front-passenger doo r is closed, th e vehi-
cl e locks .
If th e driver's doo r is open, th e doo r stays
unlocked.
Meanwhile, th e fue l filler flap will no t be locke d
or unlocked.
You canno t unloc k th e vehicle centrall y from th e
insid e if th e vehicle has bee n locke d wit h th e
SmartKey or KEYLESS-GO .
The doors can be opene d from th e inside. You
can only ope n th e rea r doors from insid e th e
vehicle if they are no t secure d by th e child-proof
locks ( Y
page 65).
If th e vehicle has bee n locke d wit h th e SmartKey
or wit h KEYLESS-GO , opening a doo r from th e
insid e will trigger th e anti-thef t alar m system.
Switc h of f th e alar m ( Y
page 76) .Doors 83
Opening and closing Z

X
To lock: turn the mechanical key clockwise as
far as it will go to position G .X
To unlock: turn the mechanical key counter-
clockwise as far as it will go to position G .
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 76).
Trunk
Important safety notes
G WARNING
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. Exhaust
gases can enter the vehicle interior if the
trunk lid is open when the engine is running,
especially if the vehicle is in motion. There is a
risk of poisoning.
Always switch off the engine before opening
the trunk lid. Never drive with the trunk lid
open.
G WARNING
If objects, luggage or loads are not secured or
not secured sufficiently, they could slip, tip
over or be flung around and thereby hit vehicle
occupants. There is a risk of injury, particu-
larly in the event of sudden braking or a sud-
den change in direction.
Always store objects so that they cannot be
flung around. Secure objects, luggage or
loads against slipping or tipping before the
journey. ! The trunk lid swings upwards when opened.
Therefore, make sure that there is sufficient
clearance above the trunk lid.
You can limit the opening angle of the trunk lid in
the multimedia system; see the Digital Opera-
tor's Manual.
The opening dimensions of the trunk lid can be
found in the "Vehicle data" section
( Y
page 376).
Do not leave the SmartKey in the trunk. You
could otherwise lock yourself out.
You should preferably place luggage or loads in
the trunk. Observe the loading guidelines
( Y
page 281).
Obstruction detection with reversing
feature for the trunk lid Vehicles with trunk lid remote closing fea-
ture:
The trunk lid is equipped with automatic
obstruction detection with a reversing feature. If
a solid object blocks or restricts the trunk lid
when automatically opening or closing, this pro-
cedure is stopped. If the trunk lid is stopped
during the closing procedure, it will open again
automatically. The automatic obstruction detec-
tion with reversing feature is only an aid. It is not
a substitute for your attentiveness when open-
ing and closing the trunk lid.
G WARNING
The reversing feature does not respond: R
to soft, light and thin objects, e.g. fingers R
over the last 1/3 in (8 mm) of the closing
movement
The reversing feature cannot prevent some-
one being trapped in these situations in par-
ticular. There is a risk of injury.
Make sure that no body parts are in close
proximity during the closing procedure.
If somebody becomes trapped: R
press the T button on the SmartKey, or R
pull or press the remote operating switch
on the driver's door or R
press the closing or locking button on the
trunk lid, or R
pull on the trunk lid handle Trunk 85
Opening and closing Z

vehicle. Always keep the SmartKey out of
reach of children.
G WARNING
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. Inhaling
these exhaust gases leads to poisoning. There
is a risk of fatal injury. Therefore never leave
the engine running in enclosed spaces with-
out sufficient ventilation.
G WARNING
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 higher
speeds to enable the catalytic converter to
reach its operating temperature. The sound of
the engine may change during this time.
Automatic transmission X
Shift the transmission to position P
( Y
page 152).
The transmission position display in the mul-
tifunction display shows P ( Y
page 154).
You can start the engine in transmission posi-
tion P and N .
Starting procedure with the SmartKey To start the engine using the SmartKey instead
of the Start/Stop button, pull the Start/Stop
button out of the ignition lock. X
Turn the SmartKey to position 3 in the ignition
lock and release it as soon as the engine is
running ( Y
page 145). Starting procedure with the Start/Stop
button The Start/Stop button can be used to start the
vehicle manually without inserting the SmartKey
into the ignition lock. The Start/Stop button
must be inserted in the ignition lock and the
SmartKey must be in the vehicle. This mode for
starting the engine operates independently of
the ECO start/stop automatic engine start func-
tion.
You can start the engine if a valid SmartKey is in
the vehicle. Always take 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. X
Depress the brake pedal and keep it
depressed. X
Press the Start/Stop button once
( Y
page 145).
The engine starts.
Starting procedure via smartphone Observe the important safety notes on starting
the engine ( Y
page 146).
You can also start your engine via your smart-
phone from outside the vehicle. In this case, the
previously selected climate control setting is
activated. In this way you can cool or heat the
interior of the vehicle before starting the jour-
ney.
Only start the engine via your smartphone if it is
safe to start and run the engine where your vehi-
cle is parked.
Observe the legal stipulations in the area where
your vehicle is parked. Engine start via smart-
phone may be limited to certain countries or
regions.
You can execute a maximum of two consecutive
starting attempts via your smartphone. If you
insert the SmartKey into the ignition lock, you
can carry out two more starting attempts.
Once you have started the engine, you can
switch the engine off via your smartphone at any
time.
You can only start the engine via your smart-
phone if: R
the SmartKey is in the ignition lock R
park position P is selected R
the accelerator pedal is not depressed R
the anti-theft alarm system is not activated Driving 147
Driving and parking Z

R
the panic alarm is not activated R
the hazard warning lamps are switched off R
the hood is closed. R
the doors are closed and locked R
the windows and sliding sunroof are closed
Also make sure that: R
the fuel tank is sufficiently filled R
the starter battery is sufficiently charged
G WARNING
Limbs could be crushed or trapped if the
engine is started unintentionally during ser-
vice or maintenance work. There is a risk of
injury.
Always secure the engine against uninten-
tional starting before carrying out mainte-
nance or repair work.
Make sure that the engine cannot be started via
your smartphone before carrying out mainte-
nance or repairs. You can prevent an engine
start via your smartphone, for example, if you: R
switch on the hazard warning lamps R
do not lock the doors R
open the hood
Pulling away
General notes
G WARNING
If the engine speed is above the idling speed
and you engage transmission position D or R ,
the vehicle could pull away suddenly. There is
a risk of an accident.
When engaging transmission position D or R ,
always firmly depress the brake pedal and do
not simultaneously accelerate.
Depress the accelerator carefully when pulling
away.
The vehicle locks centrally once you have pulled
away. The locking knobs in the doors drop down.
You can open the doors from the inside at any
time.
You can also deactivate the automatic locking
feature ( Y
page 84). It is only possible to shift the transmission from
position P to the desired position if you depress
the brake pedal. Only then is the parking lock
released.
If you do not depress the brake pedal, the
DIRECT SELECT lever can still be moved but the
parking lock remains engaged.
i Upshifts take place at higher engine speeds
after a cold start. This helps the catalytic con-
verter to reach its operating temperature
more quickly.
Information on the automatic release of the
electric parking brake ( Y
page 164).
Hill start assist Hill start assist helps you when pulling away for-
wards or in reverse on an uphill gradient. It holds
the vehicle for a short time after you have
removed your foot from the brake pedal. This
gives you enough time to move your foot from
the brake pedal to the accelerator pedal and to
depress it before the vehicle begins to roll.
G WARNING
After a short time, hill start assist will no lon-
ger brake your vehicle and it could roll away.
There is a risk of an accident and injury.
Therefore, quickly move your foot from the
brake pedal to the accelerator pedal. Never
leave the vehicle when it is held by hill start
assist.
Hill start assist is not active if: R
you are pulling away on a level road or on a
downhill gradient. R
the transmission is in position \\ .R
the electric parking brake is applied. R
ESP ®
is malfunctioning.
ECO start/stop function
Introduction
Hybrid vehicles: observe the notes on the ECO
start/stop function in the separate operating
instructions.
The ECO start/stop function switches the
engine off automatically if the vehicle is stopped
under certain conditions.148
Driving
Dr ivi ng an d parking

The engine starts automatically when the driver
wants to pull away again. The ECO start/stop
function thereby helps you to reduce the fuel
consumption and emissions of your vehicle.
Important safety notes
G WARNING
If the engine is switched off automatically and
you exit the vehicle, the engine is restarted
automatically. The vehicle may begin moving.
There is a risk of accident and injury.
If you wish to exit the vehicle, always turn off
the ignition and secure the vehicle against
rolling away.
General notes
C
ECO start/stop display
The ECO start/stop function is activated when-
ever you switch on the engine using the Smart-
Key or the Start/Stop button.
If the engine has been switched off automati-
cally by the ECO start/stop function, the

Parking
Important safety notes
G WARNING
Flammable material such as leaves, grass or
twigs may ignite if they come into contact with
hot parts of the exhaust system or exhaust
gas flow. There is a risk of fire.
Park the vehicle so that no flammable mate-
rials come into contact with parts of the vehi-
cle which are hot. Take particular care not to
park on dry grassland or harvested grain
fields.
G WARNING
If you leave children unsupervised in the vehi-
cle, they could set it in motion by, for example: R
release the parking brake. R
shift the automatic transmission out of the
parking position P .R
start the engine.
In addition, they may operate vehicle equip-
ment and become trapped. 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 unsupervised in the vehicle.
! Always secure the vehicle correctly against
rolling away. Otherwise, the vehicle or its driv-
etrain could be damaged.
To ensure that the vehicle is secured against
rolling away unintentionally: R
the electric parking brake must be applied. R
the transmission must be in position P and the
SmartKey must be removed from the ignition
lock. R
the front wheels must be turned towards the
curb on steep uphill or downhill gradients. R
the empty vehicle must be secured at the
front axle with a wheel chock or similar, for
example, on uphill or downhill gradients. R
a laden vehicle must also be secured at the
rear axle with a wheel chock or similar, for
example, on uphill or downhill gradients. Switching off the engine
G WARNING
The automatic transmission switches to neu-
tral position N when you switch off the engine.
The vehicle may roll away. There is a risk of an
accident.
After switching off the engine, always switch
to parking position P . Prevent the parked vehi-
cle from rolling away by applying the parking
brake. X
Apply the electric parking brake. X
Shift the transmission to position P .X
With the SmartKey: turn the SmartKey to
position 0 in the ignition lock and remove it.
The immobilizer is activated. X
With the Start/Stop button: press the
Start/Stop button ( Y
page 145).
The engine stops and all the indicator lamps in
the instrument cluster go out.
When the driver's door is closed, this corre-
sponds to SmartKey position 1 . When the
driver's door is open, this corresponds to
SmartKey position 0 : "Key removed".
If you switch the engine off with the transmis-
sion in position R or D , the automatic transmis-
sion shifts to N automatically.
With the SmartKey: if you then open the driv-
er's door or the front-passenger door or remove
the SmartKey from the ignition, the automatic
transmission shifts to P automatically.
With the Start/Stop button: if you then open
the driver's door or the front-passenger door,
the automatic transmission shifts to P automat-
ically.
If you want the automatic transmission to
remain in neutral N , e.g. when having the vehicle
cleaned in an automatic car wash with a towing
system: X
Remove the Start/Stop button from the igni-
tion lock. X
Insert the SmartKey into the ignition lock. X
Switch on the ignition. X
Depress the brake pedal and keep it
depressed. X
Shift to neutral N .X
Release the brake pedal.162
Parking
Driving and parking

X
Releas e th e electric parking brake.X
Switc h off th e ignition and leav e th e SmartKey
in th e ignition lock.
The engin e can be switched off in an emergenc y
while th e vehicl e is in motion by pressin g and
holding th e Start/Sto p butto n for three sec -
onds. This function operate s independentl y of
th e ECO start/sto p automatic engin e switch-off
function .
Electric parking brake
General notes
G WARNIN G
If you leav e children unsupervised in th e vehi-
cle , they could set it in motion by, for example: R
release th e parking brake.R
shif t th e automatic transmission out of th e
parking position P .R
start th e engine.
In addition , they may operate vehicl e equip-
men t and become trapped . There is a ris k of
an acciden t and injury.
When leaving th e vehicle, always tak e th e
SmartKey wit h you and loc k th e vehicle. Never
leav e children unsupervised in th e vehicle.
The function of th e electric parking brak e is
dependen t on th e on-board voltage. If th e on -
boar d voltag e is low or there is a malfunction in
th e system, it may no t be possibl e to apply th e
release d parking brake.X
If this is th e case, only park th e vehicl e on
level ground and secure it to preven t it rollin g
away. X
Shift th e automatic transmission to position
P .
It may no t be possibl e to release an applie d
parking brak e if th e on-board voltag e is low or
there is a malfunction in th e system. Contac t a
qualified specialist workshop.
The electric parking brak e performs a function
test at regular intervals while th e engin e is
switched off . The sounds that can be hear d while
this is occurrin g are normal. Applying or releasing manually X
To engage: push handle C .
When th e electric parking brak e is applied,
th e red I (US A only) or $ (Canada
only) indicator lamp lights up in th e instru-
men t cluster.
The electric parking brak e can also be applie d
when th e SmartKey is removed. X
To release: pull handle C .
The red I (US A only) or $ (Canada
only) indicator lamp in th e instrumen t cluste r
goes out .
The electric parking brak e can only be released:R
when th e SmartKey is in position 1 or 2 in th e
ignition loc k ( Y
page 145) or R
if th e ignition was switched on usin g th e
Start/Sto p butto n
Applying automatically The electric parking brak e is automatically
applie d when th e transmission is in position P
and : R
th e engin e is switched off or R
th e driver is no t wearing a seat belt and th e
driver' s door is opened
To preven t th e electric parking brak e from bein g
automatically applied, pull handle C .
The electric parking brak e is also engage d auto -
matically if: R
DISTRONI C PLU S brings th e vehicl e to a
standstill or R
th e HOLD function is keepin g th e vehicl e sta-
tionary R
Active Parking Assis t is keepin g th e vehicl e
stationary Parking 163
Driving and parking Z