MERCEDES-BENZ S CLASS 2017 Repair Manual

R
the front side windows are lowered R
the electrically adjustable steering wheel is
raised R
the engine is switched off and the fuel supply
is cut off R
vehicles with seat belt extenders: the seat-
belt buckles for the outer rear seats are illu-
minated and extend forwards R
vehicles with mbrace: automatic emergency
call
Children in the vehicle
Important safety notes Accident statistics show that children secured
in the rear seats are safer than children secured
in the front-passenger seat. For this reason,
Mercedes-Benz strongly advises that you install
a child restraint system on a rear seat. Children
are generally better protected there.
If a child younger than twelve years old and
under 5 ft (1.50 m) in height is traveling in the
vehicle: R
always secure the child in a child restraint
system suitable for Mercedes-Benz vehicles.
The child restraint system must be appropri-
ate to the age, weight and size of the child R
be sure to observe the instructions and safety
notes in this section in addition to the child
restraint system manufacturer's installation
instructions R
be sure to observe the instructions and safety
notes on the "Occupant classification system
(OCS)" ( Y
page 51)
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. G WARNING
If persons, particularly children are subjected
to prolonged exposure to extreme heat or
cold, there is a risk of injury, possibly even
fatal. Never leave children unattended in the
vehicle.
G WARNING
If the child restraint system is subjected to
direct sunlight, parts may get very hot. Chil-
dren may burn themselves on these parts,
particularly on the metal parts of the child
restraint system. There is a risk of injury.
If you leave the vehicle, taking the child with
you, always ensure that the child restraint
system is not exposed to direct sunlight. Pro-
tect it with a blanket, for example. If the child
restraint system has been exposed to direct
sunlight, let it cool down before securing the
child in it. Never leave children unattended in
the vehicle.
Always ensure that all vehicle occupants have
their seat belts fastened correctly and are sitting
properly. Particular attention must be paid to
children.
Observe the safety notes on the seat belt
( Y
page 44) and the notes on correct use of seat
belts ( Y
page 45).
A booster seat may be necessary to achieve
proper seat belt positioning for children over
41 lb s( 18 kg) until they reach a height where a
three-point seat belt can be properly fastened
without a booster seat.
Special seat belt retractor
G WARNING
If the seat belt is released while driving, the
child restraint system will no longer be
secured properly. The special seat belt retrac-
tor is disabled and the inertia real draws in a
portion of the seat belt. The seat belt cannot
be immediately refastened. There is an
increased risk of injury, possibly even fatal.
Stop the vehicle immediately, paying atten-
tion to road and traffic conditions. ReactivateChildren in the vehicle 59
Safety Z

the special seat belt retractor and secure the
child restraint system properly.
All seat belts except the driver's seat belt are
equipped with a special seat belt retractor.
When activated, the special seat belt retractor
ensures that the seat belt will not slacken once
the child restraint system has been secured.
Installing a child restraint system: X
Always comply with the child restraint system
manufacturer's installation instructions. X
Pull the seat belt smoothly from the belt out-
let. X
Engage the seat belt tongue in the belt buckle.
Activating the special seat belt retractor: X
Pull the seat belt out fully and let the inertia
reel retract it again.
While the seat belt is retracting, you should
hear a ratcheting sound. The special seat belt
retractor is activated. X
Push the child seat restraint system down so
that the seat belt is tight and does not loosen.
Removing a child restraint system and deacti-
vating the special seat belt retractor: X
Always comply with the child restraint system
manufacturer's installation instructions. X
Press the release button of the belt buckle,
hold the belt tongue firmly and guide it back
to w ards the belt outlet.
The special seat belt retractor is deactivated.
Child restraint system The use of seat belts and child restraint systems
is required by law in: R
all 50 states R
the U.S. territories R
the District of Columbia R
all Canadian provinces
You can obtain further information about the
correct child restraint system from any author-
ized Mercedes-Benz Center.
G WARNING
If the child restraint system is installed incor-
rectly on a suitable seat, it cannot protect as
intended. The child cannot then be restrained
in the event of an accident, heavy braking or sudden changes of direction. There is an
increased risk of injury, possibly even fatal.
Make sure that you observe the child restraint
system manufacturer's installation instruc-
tions and the notes on use. Please ensure,
that the base of the child restraint system is
always resting completely on the seat cush-
ion. Never place objects, e.g. cushions, under
or behind the child restraint system. Only use
child restraint systems with the original cover
designed for them. Only replace damaged
covers with genuine covers.
G WARNING
If the child restraint system is installed incor-
rectly or is not secured, it can come loose in
the event of an accident, heavy braking or a
sudden change in direction. The child
restraint system could be thrown about, strik-
ing vehicle occupants. There is an increased
risk of injury, possibly even fatal.
Always install child restraint systems prop-
erly, even if they are not being used. Make
sure that you observe the child restraint sys-
tem manufacturer's installation instructions.
You will find further information on stowing
objects, luggage or loads under "Loading guide-
lines" ( Y
page 281).
G WARNING
Child restraint systems or their securing sys-
tems which have been damaged or subjected
to a load in an accident can no longer protect
as intended. The child cannot then be
restrained in the event of an accident, heavy
braking or sudden changes of direction. There
is an increased risk of injury, possibly even
fatal.
Replace child restraint systems which have
been damaged or subjected to a load in an
accident as soon as possible. Have the secur-
ing systems on the child restraint system
checked at a qualified specialist workshop,
before you install a child restraint system
again.60
Children in the vehicle
Safety

The securing systems of child restraint systems
are: R
the seat belt system R
the LATCH-type (ISOFIX) securing rings R
the Top Tether anchorages
If it is absolutely necessary to carry a child on
the front-passenger seat, be sure to observe the
information on the "Occupant Classification
System (OCS)" ( Y
page 51). There you will also
find information on deactivating the front-
passenger front air bag.
All child restraint systems must meet the fol-
lowing standards: R
U.S. Federal Motor Vehicle Safety Standards
213 and 225 R
Canadian Motor Vehicle Safety Standards
213 and 210.2
Confirmation that the child restraint system cor-
responds to the standards can be found on an
instruction label on the child restraint system.
This confirmation can also be found in the instal-
lation instructions that are included with the
child restraint system.
Observe the warning labels in the vehicle inte-
rior and on the child restraint system.
Vehicles with seat belt extenders: when
securing a child in a child restraint system on a
rear seat, observe the following instructions: R
make sure that the seat belt on the child
restraint system is fastened according to the
manufacturer's installation instructions for
the child restraint system. R
for child restraint systems with a belt clamp:
engage the belt tongue in the buckle before
you tighten the seat belt using the belt clamp.
Vehicles with a rear reclining seat: when
installing a child restraint system, move the rear
reclining seat backrest to an almost vertical
position. The rear reclining seat backrest must
rest against the child restraint system. Observe
the notes on the cushion air bag ( Y
page 50).
Vehicles with belt bags: only use a child
restraint system which has been approved by
Mercedes-Benz. Always observe the instruc-
tions and safety notes on belt bags for the outer
seat belts in the rear ( Y
page 46). LATCH-type (ISOFIX) child seat secur-
ing system
G WARNING
LATCH-type (ISOFIX) child restraint systems
do not offer sufficient protective effect for
children whose weight is greater than 48 lbs
(22 kg) who are secured using the safety belt
integrated in the child restraint system. In the
event of an accident, a child might not be
restrained correctly. This poses an increased
risk of injury or even fatal injury.
If the child weighs more than 48 lbs (22 kg),
only use LATCH-type (ISOFIX) child restraint
systems with which the child is also secured
with the vehicle seat belt. Also secure the
child restraint system with the Top Tether
belt, if available.
Always comply with the manufacturer's instal-
lation and operating instructions for the child
restraint system used.
Before every trip, make sure that the LATCH-
type (ISOFIX) child restraint system is engaged
correctly in both LATCH-type (ISOFIX) securing
rings
! When installing the child restraint system,
make sure that the seat belt for the middle
seat does not get trapped. The seat belt could
otherwise be damaged.
LATCH-type (ISOFIX) securing rings D on the
rear seats are covered by a Velcro-fastened
upholstered lining C .X
Vehicles with a rear reclining seat: adjust
the rear reclining seat backrest down a littleChildren in the vehicle 61
Safety Z

before installing the LATCH-type (ISOFIX)
child restraint system. X
Vehicles without rear reclining seat: fold
upholstered lining C upwards.X
Vehicles with a rear reclining seat: remove
upholstered lining C .X
Vehicles without a rear reclining seat: turn
the support on the rear side of upholstered
lining C by 90°.
Upholstered lining C remains folded
upwards. X
Install the LATCH-type (ISOFIX) child restraint
system on both LATCH-type (ISOFIX) securing
rings D .X
Vehicles with a rear reclining seat: move
the rear reclining seat backrest to an upright
position. The rear reclining seat backrest
must rest against the child restraint system.
G WARNING
Vehicles with electrically adjustable rear
bench seats:
If you adjust the seat after installing a child
restraint system: R
the seat belt could slacken or become too
tight R
the child restraint system could become
loose, incorrectly positioned or damaged
As a result, the child restraint system may not
be able to provide the intended level of pro-
tection. This poses an increased risk of injury
or even fatal injury.
Never adjust the seat after installing the child
restraint system.
Vehicles without rear reclining seat: after
you have removed the LATCH-type (ISOFIX)
child restraint system, you must turn the sup-
port on the rear side of upholstered lining C by
90° again. Then fold upholstery lining C down.
ISOFIX is a standardized securing system for
specially designed child restraint systems on
the rear seats. LATCH-type (ISOFIX) securing
rings D for two LATCH-type (ISOFIX) child
restraint systems are installed on the left and
right rear seats.
Vehicles with rear seat armrest: adjust the
rear seat armrest so that LATCH-type (ISOFIX)
securing rings D for the LATCH-type (ISOFIX)
child restraint system are accessible. Non-LATCH-type (ISOFIX) child seats may also
be used and can be installed using the vehicle's
seat belt system. Install the child seat according
to the manufacturer's instructions.
Top Tether
Introduction Top Tether provides an additional connection
between the child restraint system secured with
a LATCH-type (ISOFIX) system and the vehicle.
This helps reduce the risk of injury even further.
If the child restraint system is equipped with a
Top Tether belt, this should always be used.
Important safety notes
G WARNING
If the rear seat backrests are not locked, they
could fold forwards in the event of an acci-
dent, heavy braking or sudden changes of
direction. As a result, child restraint systems
cannot perform their intended protective
function. Rear seat backrests that are not
locked can also cause additional injuries, e.g.
in the event of an accident. This poses an
increased risk of injury or even fatal injury.
Always lock rear seat backrests after instal-
ling a Top Tether belt. Observe the lock veri-
fication indicator. Adjust the rear seat backr-
ests so that they are in an upright position.
G WARNING
Vehicles with electrically adjustable rear
bench seats:
If you adjust the seat after installing a child
restraint system: R
the seat belt could slacken or become too
tight R
the child restraint system could become
loose, incorrectly positioned or damaged
As a result, the child restraint system may not
be able to provide the intended level of pro-
tection. This poses an increased risk of injury
or even fatal injury.62
Children in the vehicle
Safety

Never adjust the seat after installing the child
restraint system.
If the rear seat backrest is not engaged and
locked, this will be shown in the multifunction
display in the instrument cluster. A warning tone
also sounds.
Top Tether anchorages
The Top Tether anchorage points are installed in
the rear compartment behind the head
restraints on the parcel shelf.
X
Move the head restraint up ( Y
page 111).X
Fold up cover C of the Top Tether anchorage.X
Install the LATCH-type (ISOFIX) child restraint
system with Top Tether. Always comply with
the child restraint system manufacturer's
installation instructions when doing so. X
Route Top Tether belt

of the child restraint system must always rest on
the seat cushion of the front-passenger seat.
The backrest of the child restraint system must
lie as flat as possible against the backrest of the
front-passenger seat. The child restraint system
must not touch the roof or be subjected to a load
by the head restraint. Adjust the angle of the
seat backrest and the head restraint position
accordingly. Always make sure that the shoul-
der belt strap is correctly routed from the vehi-
cle belt outlet to the shoulder belt guide on the
child restraint system. The shoulder belt strap
must be routed forwards and downwards from
the vehicle belt outlet. If necessary, adjust the
vehicle belt outlet and the front-passenger seat
accordingly.
Always observe the child restraint system man-
ufacturer's installation and operating instruc-
tions.
Child-proof locks
Important safety notes
G WARNING
If children are traveling in the vehicle, they
could: R
open doors, thus endangering other people
or road users R
exit the vehicle and be caught by oncoming
traffic R
operate vehicle equipment and become
trapped
There is a risk of an accident and injury.
Always activate the child-proof locks and
override feature if children are traveling in the
vehicle. When leaving the vehicle, always take
the key with you and lock the vehicle. Never
leave children unattended in the vehicle.
Override feature for: R
the rear doors ( Y
page 65)R
the rear side windows ( Y
page 65) 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.
G WARNING
If persons, particularly children are subjected
to prolonged exposure to extreme heat or
cold, there is a risk of injury, possibly even
fatal. Never leave children unattended in the
vehicle.
G WARNING
If the child restraint system is subjected to
direct sunlight, parts may get very hot. Chil-
dren may burn themselves on these parts,
particularly on the metal parts of the child
restraint system. There is a risk of injury.
If you leave the vehicle, taking the child with
you, always ensure that the child restraint
system is not exposed to direct sunlight. Pro-
tect it with a blanket, for example. If the child
restraint system has been exposed to direct
sunlight, let it cool down before securing the
child in it. Never leave children unattended in
the vehicle.64
Children in the vehicle
Safety

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

R
ESP ®
( E lectronic S tability P rogram)
( Y
page 71)R
EBD ( E lectronic B rake force D istribution)
( Y
page 73)R
ADAPTIVE BRAKE ( Y
page 73)R
PRE-SAFE ®
Brake ( Y
page 73)R
STEER CONTROL ( Y
page 75)
Important safety notes If you fail to adapt your driving style or if you are
inattentive, the driving safety systems can nei-
ther reduce the risk of an accident nor override
the laws of physics. Driving safety systems are
merely aids designed to assist driving. You are
responsible for maintaining the distance to the
vehicle in front, for vehicle speed, for braking in
good time, and for staying in lane. Always adapt
your driving style to suit the prevailing road and
weather conditions and maintain a safe distance
from the vehicle in front. Drive carefully.
The driving safety systems described only work
as effectively as possible when there is ade-
quate contact between the tires and the road
surface. Pay particular attention to the informa-
tion regarding tires, recommended minimum
tire tread depths etc. in the "Wheels and tires"
section ( Y
page 343).
In wintry driving conditions, always use winter
tires (M+S tires) and if necessary, snow chains.
Only in this way will the driving safety systems
described in this section work as effectively as
possible.
ABS (Anti-lock Braking System)
General information ABS regulates brake pressure in such a way that
the wheels do not lock when you brake. This
allows you to continue steering the vehicle when
braking.
The % ABS warning lamp in the instrument
cluster lights up when the ignition is switched
on. 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 you
only brake gently. Important safety notes
i Observe the "Important safety notes" sec-
tion ( Y
page 66).
G WARNING
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 also
become inoperative. Observe the information
on the ABS warning lamp ( Y
page 261) and dis-
play messages which may be shown in the
instrument cluster ( Y
page 228).
Braking X
If ABS intervenes: continue to depress the
brake pedal vigorously until the braking sit-
uation is over. X
To make a full brake application: depress
the brake pedal with full force.
If ABS intervenes when braking, you will feel a
pulsing in the brake pedal.
The pulsating brake pedal can be an indication
of hazardous road conditions, and functions as a
reminder to take extra care while driving.
BAS (Brake Assist System)
General information BAS operates in emergency braking situations.
If you depress the brake pedal quickly, BAS
automatically boosts the braking force, thus
shortening the stopping distance.
Important safety notes
i Observe the "Important safety notes" sec-
tion ( Y
page 66).66
Driving safet y system s
Sa fety

G WARNING
If BAS is malfunctioning, the braking distance
in an emergency braking situation is
increased. There is a risk of an accident.
In an emergency braking situation, depress
the brake pedal with full force. ABS prevents
the wheels from locking.
Brakes X
Keep the brake pedal firmly depressed until
the emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will function as usual once you
release the brake pedal. BAS is deactivated.
BAS PLUS (Brake Assist System
PLUS) with Cross-Traffic Assist
General information BAS PLUS can help you to minimize the risk of a
collision with a vehicle or a pedestrian and
reduce the effects of such a collision. If BAS
PLUS detects a danger of collision, you are
assisted when braking.
i Pay attention to the important safety notes
in the "Driving safety systems" section
( Y
page 66).
BAS PLUS is only available in vehicles with the
Driving Assistance Plus package.
For BAS PLUS to assist you when driving, the
radar sensor system and the camera system
must be operational.
With the help of a sensor system and a camera
system, BAS PLUS can detect obstacles: R
that are in the path of your vehicle for an
extended period of time R
that cross the path of your vehicle
In addition, pedestrians in the path of your vehi-
cle can be detected.
BAS PLUS detects pedestrians by using typical
characteristics such as the body contours and
posture of a person standing upright.
If the radar sensor system or the camera system
is malfunctioning, BAS PLUS functions are
restricted or no longer available. The brake sys-
tem is still available with complete brake boost-
ing effect and BAS. i Observe the restrictions described in the
"Important safety notes" section
( Y
page 67).
Important safety notes
G WARNING
BAS PLUS cannot always clearly identify
objects and complex traffic situations.
In such cases, BAS PLUS may: R
intervene unnecessarily R
not intervene
There is a risk of an accident.
Always pay careful attention to the traffic sit-
uation and be ready to brake. Terminate the
intervention in a non-critical driving situation.
G WARNING
BAS PLUS cannot always clearly identify peo-
ple, this is especially the case if they are mov-
ing. BAS PLUS cannot intervene in these
cases. There is a risk of an accident.
Always pay careful attention to the traffic sit-
uation and be ready to brake.
G WARNING
BAS PLUS does not react: R
to small people, e.g. children R
to animals R
to oncoming vehicles R
when cornering
As a result, BAS PLUS may not intervene in all
critical situations. There is a risk of an acci-
dent.
Always pay careful attention to the traffic sit-
uation and be ready to brake.
In the event of snowfall or heavy rain, the rec-
ognition can be impaired.
Recognition by the radar sensor system is also
impaired if: R
there is dirt on the sensors or anything else
covering the sensors R
there is interference by other radar sources R
there are strong radar reflections, for exam-
ple in parking garagesDriving safety systems 67
Safety Z

R
a narrow vehicle is traveling in front, e.g. a
motorbike R
a vehicle is traveling in front on a different line R
vehicles quickly move into the radar sensor
system detection range
Recognition by the camera system is also
impaired in the event of: R
dirt on the camera or if the camera is covered R
glare on the camera system, e.g. from the sun
being low in the sky R
darkness R
or if: -
pedestrians move quickly, e.g. into the path
of the vehicle -
the camera system no longer recognizes a
pedestrian as a person due to special cloth-
ing or other objects -
a pedestrian is concealed by other objects -
the typical outline of a person is not distin-
guishable from the background
Following damage to the front end of the vehicle,
have the configuration and operation of the
radar sensors checked at a qualified specialist
workshop. This also applies to collisions at slow
speeds where there is no visible damage to the
front of the vehicle.
Following damage to the windshield, have the
configuration and operation of the camera sys-
tem checked at a qualified specialist workshop.
Function To avoid a collision, BAS PLUS calculates the
brake force necessary if: R
you approach an obstacle, and R
BAS PLUS has detected a risk of collision
When driving at a speed
under20 mph(30 km/h) : if you depress the
brake pedal, BAS PLUS is activated. The
increase in brake pressure will be carried out at
the last possible moment.
When driving at a speed
above20 mph(30 km/h) : if you depress the
brake pedal sharply, BAS PLUS automatically
raises the brake pressure to a value adapted to
the traffic situation.
BAS PLUS provides braking assistance in haz-
ardous situations with vehicles in front within a
speed range between 4 mph (7 km/h) and
155 mph (25 0 km/ h) . At speeds of up to approximately 44 mph
(70 km/h), BAS PLUS can react to: R
stationary objects in the path of your vehicle,
e.g. stopped or parked vehicles R
pedestrians in the path of your vehicle R
obstacles crossing your path, which move in
the detection range of the sensors and are
recognized by them
i If BAS PLUS demands particularly high brak-
ing force, preventative passenger protection
measures (PRE-SAFE ®
) are activated simulta-
neously ( Y
page 57). X
Keep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the wheels from locking.
BAS P LUS is deactivated and the brakes func-
ti
on as usual, if: R
you release the brake pedal. R
there is no longer a risk of collision. R
no obstacle is detected in front of your vehi-
cle. R
you depress the accelerator pedal. R
you activate kickdown.
COLLISION PREVENTION ASSIST
PLUS
General information COLLISION PREVENTION ASSIST PLUS consists
of a distance warning function with an autono-
mous braking function and Adaptive Brake
Assist.
COLLISION PREVENTION ASSIST PLUS can help
you to minimize the risk of a front-end collision
with a vehicle ahead or reduce the effects of
such a collision.
If COLLISION PREVENTION ASSIST PLUS
detects that there is a risk of a collision, you will
be warned visually and acoustically. If you do not
react to the visual and audible collision warning,
autonomous braking can be initiated in critical
situations. If you apply the brake yourself in a
critical situation, the COLLISION PREVENTION
ASSIST PLUS adaptive Brake Assist assists you.68
Driving safety systems
Safety