light MERCEDES-BENZ M-Class 2015 W166 Owner's Guide

If OCS determines that:
R the front-passenger seat is unoccupied, the
PASSENGER AIR BAG OFF indicator lamp
lights up after the system self-test and
remains lit. This indicates that the front-
passenger front air bag is deactivated.
R the front-passenger seat is occupied by a
child of up to 12 months old, in a standard
child restraint system, the PASSENGER AIR BAG OFF indicator lamp lights up after the
system self-test and remains lit. This indi-
cates that the front-passenger front air bag
is deactivated.
But in the case of a 12-month-old child, in a standard child restraint system, the
PASSENGER AIR BAG OFF indicator lamp
can go out after the system self-test. This
indicates that the front-passenger front air
bag is activated. The result of the classifi-
cation is dependent on, among other fac-
tors, the child restraint system and the
child's stature. It is recommended that you
install the restraint system on a suitable
rear seat.
R the front-passenger seat is occupied by a
person of smaller stature (e.g. a teenager
or small adult), the PASSENGER AIR BAG
OFF indicator lamp lights up and remains lit after the system self-test depending on the result of the classification or, alternatively,
goes out.
- if the PASSENGER AIR BAG OFF indicator
lamp is off, move the front-passenger
seat as far back as possible. Alterna-
tively, a person of small stature can sit on
a rear seat.
- if the PASSENGER AIR BAG OFF indicator
lamp is lit, a person of smaller stature
should not use the front-passenger seat.
R the front-passenger seat is occupied by an
adult or a person of a stature correspond-
ing to that of an adult, the PASSENGER AIR BAG OFF indicator lamp goes out after the
system self-test. This indicates that the
front-passenger front air bag is activated. If children are traveling in the vehicle, be sure
to observe the notes on "Children in the vehi-
cle" (Y page 61).
When OCS is malfunctioning, the red 0075
restraint system warning lamp in the instru-
ment cluster and the PASSENGER AIR BAG
OFF indicator lamp light up simultaneously.
The front-passenger front air bag is deactiva-
ted in this case and does not deploy during an accident. Have the system checked by quali-
fied technicians as soon as possible. Consult
an authorized Mercedes-Benz Center. The
front-passenger seat should only be repaired at an authorized Mercedes-Benz Center.
If the front-passenger seat, the seat cover orthe seat cushion is damaged, have the nec-
essary repair work carried out at an author-
ized Mercedes-Benz Center.
For safety reasons, Mercedes-Benz recom-
mends that you only use seat accessories
that have been approved by Mercedes-Benz.
If the driver's air bag deploys, this does not
mean that the front-passenger front air bag
will also deploy. The Occupant Classification
System (OCS) categorizes the occupant in the
front-passenger seat. Depending on that
result, the front-passenger front air bag is
either enabled or deactivated.
System self-test G
DANGER
If the PASSENGER AIR BAG OFF indicator
lamp does not light up during the system self- test, then the system is malfunctioning. The
front-passenger front air bag might be trig-
gered unintentionally or might not be trig-
gered at all in the event of an accident with
high deceleration. This poses an increased
risk of injury or even fatal injury.
In this case the front-passenger seat may not be used. Do not install a child restraint system
on the front-passenger seat. Have the Occu-
pant Classification System (OCS) checked
and repaired immediately at a qualified spe-
cialist workshop. Occupant safety
55Safety Z

Problems with the Occupant Classification System (OCS)
Be sure to observe the notes on "System self-test" (Y
page 55).Problem
Possible causes/consequences and
0050
0050Solutions The PASSENGER AIR
BAG OFF indicator
lamp lights up and
remains lit, even
though the front-
passenger seat is occu-
pied by an adult or a
person of a stature cor-
responding to that of an
adult. The classification of the person on the front-passenger seat is
incorrect.
X Make sure the conditions for a correct classification of the per-
son on the front-passenger seat are met (Y page 53).
X If the PASSENGER AIR BAG OFF indicator lamp remains lit, the
front-passenger seat may not be used.
X Have OCS checked as soon as possible at an authorized
Mercedes-Benz Center. The PASSENGER AIR
BAG OFF indicator
lamp does not light up
and/or does not stay
on.
The front-passenger
seat is:
R unoccupied
R occupied by the
weight of a child up
to 12 months old in a
child restraint sys-
tem OCS is malfunctioning.
X Make sure there is nothing between the seat cushion and the
child seat.
X Make sure that the entire base of the child restraint system rests
on the seat cushion of the front-passenger seat. The backrest of
the forwards-facing child restraint system must, as far as pos-
sible, be resting on the backrest of front-passenger seat. If nec- essary, adjust the position of the front-passenger seat.
X When installing the child restraint system, make sure that the
seat belt is tight. Do not pull the seat belt tight with the front-
passenger seat adjustment. This could result in the seat belt and the child restraint system being pulled too tightly.
X Check the installation of the child restraint system.
Make sure that the head restraint does not apply a load to the
child restraint system. If necessary, adjust the head restraint
accordingly.
X Make sure that no objects are applying additional weight onto
the seat.
X If the PASSENGER AIR BAG OFF indicator lamp remains off, do
not install a child restraint system on the front-passenger seat. It is recommended that you install the restraint system on a
suitable rear seat.
X Have OCS checked as soon as possible at an authorized
Mercedes-Benz Center. Occupant safety
57Safety Z

Deployment of Emergency Tensioning
Devices and air bags
Important safety notes G
WARNING
The air bag parts are hot after an air bag has
been deployed. There is a risk of injury.
Do not touch the air bag parts. Have a
deployed air bag replaced at a qualified spe-
cialist workshop as soon as possible. G
WARNING
A deployed air bag no longer offers any pro-
tection and cannot provide the intended pro-
tection in an accident. There is an increased
risk of injury.
Have the vehicle towed to a qualified special- ist workshop in order to have a deployed air
bag replaced.
It is important for your safety and that of any passengers to have deployed air bags
replaced and to have any malfunctioning air
bags repaired. This will help to make sure the
air bags continue to perform their protective
function for the vehicle occupants in the
event of a crash. G
WARNING
Pyrotechnic Emergency Tensioning Devices
that have been deployed are no longer opera- tional and are unable to perform their inten-
ded protective function. This poses an
increased risk of injury or even fatal injury.
Therefore, have pyrotechnic Emergency Ten-
sioning Devices which have been triggered
immediately replaced at a qualified specialist workshop.
An electric motor is used by PRE-SAFE ®
to
trigger the tightening of the seat belt in haz-
ardous situations. This procedure is reversi-
ble.
If the Emergency Tensioning Devices or air
bags are deployed, you will hear a bang and a small amount of powder may also be released. The
0075restraint system warning
lamp will light up.
Only in rare cases will the bang affect your
hearing. The powder released is generally not hazardous to health, it could however cause
short-term breathing difficulties in people
with asthma or other respiratory problems. In
order to prevent breathing difficulties, you
should leave the vehicle as soon as it is safe to
do so, or open the window.
Air bags and pyrotechnic seat belt tensioners
contain perchlorate material, which may
require special handling or environmental
protection measures. Check with your local
government’s disposal guidelines. California
residents, see www.dtsc.ca.gov/
HazardousWaste/Perchlorate/
index.cfm.
Method of operation During the first stage of a collision, the
restraint system control unit evaluates impor-
tant physical data relating to vehicle deceler- ation or acceleration, such as:
R Duration
R Direction
R Intensity
Based on the evaluation of this data, the
restraint system control unit triggers the belt
tensioners in the event of a frontal or rear
collision.
An Emergency Tensioning Device can only be triggered if:
R the ignition is switched on
R the restraint system components are ready
for operation, see “Restraint system warn-
ing lamp” (Y page 45)
R the belt tongue is inserted into the buckle
on the respective front seat
The belt tensioners in the rear compartment
are triggered independently of the lock status
of the seat belts. 58
Occupant safetySafety

How the air bag system works is deter-
mined by the severity of the accident detec- ted, especially the vehicle deceleration or
acceleration, and the apparent type of acci- dent:
R frontal collision
R side impact
R rollover PRE-SAFE
®
(anticipatory occupant
protection system)
Introduction In certain hazardous situations, PRE-SAFE
®
takes pre-emptive measures to protect the
vehicle occupants.
Important safety notes !
Make sure that there are no objects in the
footwell or behind the seats. There is a dan- ger that the seats and/or objects could be
damaged when PRE-SAFE ®
is activated.
Although your vehicle is equipped with PRE-
SAFE ®
, the possibility of injury in the event of
an accident cannot be ruled out. 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.
Function PRE-SAFE
®
intervenes:
R in emergency braking situations, e.g. when
BAS is activated
R in critical driving situations, e.g. when phys-
ical limits are exceeded and the vehicle
understeers or oversteers severely
R on vehicles with the Active Driving Assis-
tance package: if BAS PLUS intervenes
powerfully or the radar sensor system
detects an imminent danger of collision in
certain situations PRE-SAFE
®
takes the following measures
depending on the hazardous situation detec-
ted:
R the front seat belts are pre-tensioned.
R if the vehicle skids, the sliding sunroof and
the side windows are closed so that only a
small gap remains. The panorama roof with power tilt/sliding panel is completely
closed.
R vehicles with the memory function: the
front-passenger seat is adjusted if it is in an
unfavorable position.
R vehicles with a multicontour seat: the air
pressure in the side bolsters of the seat
backrest is increased.
If the hazardous situation passes without
resulting in an accident, PRE-SAFE ®
slackens
the belt pre-tensioning. On vehicles with mul-
ticontour seats, the air pressure in the side
bolsters is reduced again. All settings made
by PRE-SAFE ®
can then be reversed.
If the seat belt pre-tensioning is not reduced:
X Move the seat backrest or seat back
slightly when the vehicle is stationary.
The seat belt pre-tensioning is reduced and
the locking mechanism is released.
The seat-belt adjustment is an integral part of
the PRE-SAFE ®
convenience function. Infor-
mation about the convenience function can
be found under "Belt adjustment"
(Y page 49). Automatic measures after an acci-
dent
Immediately after an accident, the following
measures are implemented, depending on
the type and severity of the impact:
R by activating the hazard warning lamps
R the emergency lighting is activated
R the vehicle doors are unlocked
R the front side windows are lowered 60
Occupant safetySafety

R
in vehicles with a memory function: the
electrically adjustable steering wheel is
raised
R the engine is switched off
R vehicles with mbrace: automatic emer-
gency call Children in the vehicle
Important safety notes
Accident statistics show that children
secured in the rear seats are safer than chil-
dren 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 pro-
tected there.
If a child younger than 12 years 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 vehi-
cles. The child restraint system must be
appropriate 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 classifica-
tion system (OCS)" (Y page 53)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 sit- ting properly. Particular attention must be
paid to children.
Observe the safety notes on the seat belt
(Y page 46) and the notes on correct use of
seat belts (Y page 47).
A booster seat may be necessary to achieve
proper seat belt positioning for children over
41 lbs (18 kg) or until they reach a height
where a lap/shoulder belt fits properly with-
out 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 Children in the vehicle
61Safety
Z

between rear seat backrests
0044and
cargo compartment cover 0043
R when the safety net is installed, Top
Tether belt 0084runs between rear seat
backrests 0044and the safety net.
X Tension Top Tether belt 0084. Make sure you
observe the child restraint system manu-
facturer's installation instructions.
X If necessary, push head restraint 0087back
down slightly (Y page 108). Make sure you
do not interfere with the correct routing of
Top Tether belt 0084. Child restraint system on the front-
passenger seat
General notes Accident statistics show that children
secured in the rear seats are safer than chil-
dren secured in the front-passenger seat. For this reason, Mercedes-Benz strongly advises
that you install a child restraint system on a
rear seat.
If it is absolutely necessary to install a child
restraint system to the front-passenger seat,
be sure to observe the instructions and safety
notes on the "Occupant classification system (OCS)" (Y page 53).
You can thus avoid the risks that could arise
as a result of:
R an incorrectly categorized person in the
front-passenger seat
R the unintentional deactivation of the front-
passenger front air bag
R the unsuitable positioning of the child
restraint system, e.g. too close to the dash-
board
Rearward-facing child restraint system If it is absolutely necessary to install a rear-
ward-facing child restraint system on the
front-passenger seat, always make sure that
the front-passenger front air bag is deactiva-
ted. Only if the PASSENGER AIR BAG OFF indicator lamp is permanently lit (Y
page 45)
is the front-passenger front air bag deactiva-
ted.
Always observe the child restraint system
manufacturer's installation and operating
instructions.
Forward-facing child restraint system If it is absolutely necessary to install a
forward-facing child restraint system on the
front-passenger seat, always move the front-
passenger seat as far back as possible. The
entire base 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, as far as possible, lie
flat against the backrest of the front-
passenger seat. The child restraint system
must not touch the roof or be put under strain
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
vehicle belt sash guide to the shoulder belt
guide on the child restraint system. The shoul- der belt strap must be routed forwards and
downwards from the vehicle belt sash guide.
If necessary, adjust the vehicle belt sash
guide and the front-passenger seat accord-
ingly.
Always observe the child restraint system
manufacturer's installation and operating
instructions. Children in the vehicle
65Safety Z

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 66)
R the rear side windows (Y page 67)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 childrestraint system has been exposed to direct
sunlight, let it cool down before securing the
child in it. Never leave children unattended in the vehicle.
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 0043.
X Make sure that the child-proof locks are
working properly.
X To deactivate: press the child-proof lock
lever down in the direction of arrow 0044.66
Children in the vehicleSafety

snow chains. Only in this way will the driv-
ing 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 vehi-
cle when braking.
The 0025 ABS warning lamp in the instrument
cluster lights up when the ignition is switched on. It goes out when the engine is running.
Important safety notes i
Observe the "Important safety notes" sec-
tion (Y page 67). 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 320) and
display messages which may be shown in the
instrument cluster (Y page 285).
ABS works from a speed of about 5 mph
(8 km/h), regardless of road-surface condi-
tions. ABS works on slippery surfaces, even
when you only brake gently. 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 indica-
tion of hazardous road conditions, and func-
tions as a reminder to take extra care while
driving.
Off-road ABS An ABS system specifically suited to off-road
terrain is activated automatically once the off-
road program is activated (Y page 251).
At speeds below 20 mph (30 km/h), the front
wheels lock cyclically during braking. The dig-
ging-in effect achieved in the process reduces the stopping distance on off-road terrain. This
limits steering capability. BAS (Brake Assist System)
General information BAS operates in emergency braking situa-
tions. 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 67). 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. 68
Driving safety systemsSafety

and the
00BAdistance warning lamp will light
up in the instrument cluster.
X Brake immediately in order to increase the
distance from the vehicle in front.
or
X Take evasive action, provided it is safe to do
so.
Due to the nature of the system, particularly
complicated but non-critical driving condi-
tions may also cause the system to display a
warning.
With the help of the radar sensor system, the
distance warning function can detect obsta-
cles that are in the path of your vehicle for an
extended period of time.
Up to a speed of about 40 mph (70 km/h), the distance warning function can also react to
stationary obstacles, such as stopped or
parked vehicles.
If you approach an obstacle and the distance
warning function detects a risk of a collision, the system will initially alert you both visually
and acoustically.
In particular, the detection of obstacles can
be impaired if:
R dirt on the sensors or anything else cover-
ing the sensors
R there is snow or heavy rain
R there is interference by other radar sources
R there are strong radar reflections, for
example in parking garages
R a narrow vehicle traveling in front, e.g. a
motorbike
R a vehicle traveling in front on a different line
relative to the center of your vehicle
R new vehicles or after the COLLISION PRE-
VENTION ASSIST system has been serv-
iced
Observe the notes in the section on break-
ing-in (Y page 156).
Following damage to the front end of the vehi-
cle, have the configuration and operation of
the radar sensor checked at a qualified spe-
cialist workshop. This also applies to colli- sions at low speeds where there is no visible
damage to the front of the vehicle.
Adaptive Brake Assist i
Observe the "Important safety notes" sec-
tion (Y page 67). G
WARNING
Adaptive Brake Assist cannot always clearly
identify objects and complex traffic situa-
tions.
In such cases, Adaptive Brake Assist 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
Adaptive Brake Assist does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R to stationary obstacles
R when cornering
As a result, Adaptive Brake Assist may not
intervene in all critical conditions. There is a
risk of an accident.
Always pay careful attention to the traffic sit- uation and be ready to brake.
Due to the nature of the system, particularly
complicated but non-critical driving condi-
tions may also cause Brake Assist to inter-
vene.
Adaptive Brake Assist aids you in braking dur-
ing hazardous situations at speeds above
4 mph (7 km/h) and uses the radar sensor
system to evaluate the traffic situation.
With the help of Adaptive Brake Assist, the
distance warning signal can detect obstacles
that are in the path of your vehicle for an
extended period of time. Driving safety systems
71Safety Z

Off-road 4ETS (Electronic Traction Sys-
tem) A 4ETS system specifically suited to off-road
terrain is activated automatically once the off-
road program is activated (Y page 251).
Important safety notes G
WARNING
If ESP ®
is malfunctioning, ESP ®
is unable to
stabilize the vehicle. Additionally, further driv- ing safety systems are deactivated. This
increases the risk of skidding and an accident.
Drive on carefully. Have ESP ®
checked at a
qualified specialist workshop.
! Vehicles with 4MATIC: only operate the
vehicle for a maximum of ten seconds on a
brake test dynamometer. Switch off the
ignition.
Application of the brakes by ESP ®
may oth-
erwise destroy the brake system.
! Vehicles with 4MATIC: function or per-
formance tests may only be carried out on
a 2-axle dynamometer. Before you operate the vehicle on such a dynamometer, please
consult a qualified workshop. You could
otherwise damage the drive train or the
brake system.
ESP ®
is deactivated if the 00BBwarning lamp
in the instrument cluster lights up continu-
ously when the engine is running.
If the 00E5 warning lamp and the 00BBwarn-
ing lamp are lit continuously, ESP ®
is not
available due to a malfunction.
Observe the information on warning lamps
(Y page 323) and display messages which
may be shown in the instrument cluster
(Y page 285).
i Only use wheels with the recommended
tire sizes. Only then will ESP ®
function
properly. Characteristics of ESP
® General information
If the
00E5 ESP warning lamp goes out before
beginning the journey, ESP ®
is automatically
active.
If ESP ®
intervenes, the 00E5ESP®
warning
lamp flashes in the instrument cluster.
If ESP ®
intervenes:
X Do not deactivate ESP ®
under any circum-
stances.
X Only depress the accelerator pedal as far as
necessary when pulling away.
X Adapt your driving style to suit the prevail-
ing road and weather conditions.
ECO start/stop function
The ECO start/stop function switches the
engine off automatically when the vehicle
stops moving. The engine starts automati-
cally when the driver wants to pull away again. ESP ®
remains in its previously selected sta-
tus. Example: if ESP®
was deactivated before
the engine was switched off, ESP ®
remains
deactivated when the engine is switched on
again.
Deactivating/activating ESP ® Important safety notes
You can select between the following states
of ESP
®
:
R ESP ®
is activated.
R ESP ®
is deactivated. G
WARNING
If you deactivate ESP ®
, ESP ®
no longer sta-
bilizes the vehicle. There is an increased risk
of skidding and an accident.
Only deactivate ESP ®
in the situations descri-
bed in the following. Driving safety systems
73Safety Z