2011 MERCEDES-BENZ M-Class warning light

Vehicle equipment
i This manual describes all the standard
and optional equipment of your vehicle
which was available at the time of
purchase. Country-specific differences are
possible. Bear in mind that your vehicle
may not feature all functions described
here. This also refers to safety-related
systems and functions.
Occupant safety
Overview of occupant safety
In this section you will learn the most
important facts about the restraint system
components of the vehicle.
The restraint systems are:
R Seat belts
R Child restraint systems
R "LATCH" type child seat mountings
Additional protection is provided by:
R SRS (Supplemental Restraint System)
R NECK-PRO head restraints
R PRE-SAFE ®
R Air bag system components with:
- PASSENGER air bag OFF indicator lamp
- USA only: front-passenger seat with
Occupant Classification System (OCS)
- Canada only: front-passenger seat with
BabySmart™ air bag deactivation system
The protective functions of the systems work
in conjunction with each other. The systems
are, however, autonomous.
GWarning!
Modifications to or work improperly
conducted on restraint system components
or their wiring, as well as tampering with
interconnected electronic systems, can lead
to the restraint systems no longer functioning
as intended.
Air bags or Emergency Tensioning Devices/
belt buckle tensioners, for example, could
deploy inadvertently or fail to deploy.
Therefore, never modify the restraint
systems. Do not tamper with electronic
components or their software.
i More information on the subject of
children in the vehicle and child restraint
systems can be found under the "Children
in the vehicle" chapter ( Y page 58).
SRS (Supplemental Restraint System)
Introduction
SRS reduces the risk of occupants coming
into contact with the vehicle's interior in the
event of an accident. It can also reduce the
effect of the forces to which occupants are
subjected during an accident.
SRS consists of:
R + SRS warning lamp
R air bags
R air bag control unit (with crash sensors)
R ETDs/belt buckle tensioners
R belt force limiters
SRS warning lamps
SRS functions are checked regularly when
you switch on the ignition and when the
engine is running. Therefore, malfunctions
can be detected in good time.
The + SRS warning lamp in the instrument
cluster lights up when the ignition is switched
on. It goes out no later than a few seconds
after the engine is started.
The SRS components are in operational
readiness when the + indicator lamp goes
out while the engine is running.
36Occupant safetySafety
BA 164.1 USA, CA Edition B 2011; 1; 2, en-USd2mskotVersion: 3.0.3.52010-04-21T17:25:06+02:00 - Seite 36

The front air bags increase protection for the
driver's and front-passenger's head and
chest.
Driver's front air bag : deploys in front of
the steering wheel; front-passenger front air
bag ; deploys in front of and above the glove
box. They are deployed:
R in the event of certain frontal impacts
R if the system determines that air bag
deployment can offer additional protection
to that provided by the seat belt
R if the seat belt is fastened
R independently of other air bags in the
vehicle
If the vehicle overturns, the front air bags are
generally not deployed unless the system
detects high vehicle deceleration in a
longitudinal direction.
Your vehicle has adaptive, dual-stage front air
bags. In the event of a collision, the air bag
control unit evaluates the vehicle
deceleration. When the first deployment
threshold is reached, the front air bag is filled
with enough gas to reduce the risk of injuries.
The front air bag is fully deployed if a second
deployment threshold is exceeded within a
few milliseconds.
Vehicles with OCS (USA only): front-
passenger front air bag deployment is also
influenced by the passenger's weight
category as identified by the Occupant
Classification System (OCS) ( Y page 42).
Vehicles with OCS (USA only): the lighter the
passenger side occupant, the higher the
vehicle deceleration rate required for second
stage inflation of the front-passenger front air
bag. In the second stage, the front air bags
are inflated with the maximum amount of
propellant gas available.
The air bags will not deploy in impacts which
do not exceed the system's preset
deployment thresholds. You will then be
protected by the fastened seat belts.
! Vehicles with BabySmart™ (Canada only):
do not place objects heavier than 20 lb
(9 kg) on the front-passenger seat, as this
could be interpreted as the seat being
occupied. In the event of an accident, the
restraint systems on the front-passenger
side are deployed. Have restraint systems
replaced that have been deployed.
The front-passenger front airbag will only
deploy if:
R the system, based on the OCS weight
sensor readings, detects that the front-
passenger seat is occupied (USA only).
R the 42 indicator lamp in the
center console is not lit, USA:
( Y page 42), Canada: ( Y page 48).
R the impact exceeds a preset deployment
threshold.
Side impact air bagsGWarning
Observe "Important safety instructions"
( Y page 38).
GWarning!
The pressure sensors for side impact air bag
control are located in the doors. Do not
modify any components of the doors or door
trim panels including, for example, the
addition of door speakers.
Improper repair work on the doors or the
modification or addition of components to the
doors create a risk of rendering the side
impact air bags inoperative or causing
unintended air bag deployment. Work on the
doors must therefore only be performed by
40Occupant safetySafety
BA 164.1 USA, CA Edition B 2011; 1; 2, en-USd2mskotVersion: 3.0.3.52010-04-21T17:25:06+02:00 - Seite 40

If the key has been removed from the ignition
lock or is in position 0, indicator lamp
42 : does not light up.
GWarning
If the red + SRS warning lamp in the
instrument cluster and the 42
indicator lamp light up simultaneously, OCS is
malfunctioning. The front-passenger front air
bag is disabled in this case. Have the system
checked as soon as possible by qualified
technicians. Contact an authorized
Mercedes-Benz Center.
Only have the seat repaired or replaced at an
authorized Mercedes-Benz Center.
In order to ensure proper operation of the air
bag system and OCS:
R do not place any objects with a total weight
of more than 4.4 lb(2 kg) in the parcel net
on the back of the front-passenger seat.
OCS may otherwise be unable to correctly
assess the occupant's weight category.
R do not place any objects under or near the
front-passenger seat.
R do not hang or fasten any objects on the
seats.
R do not store any objects, such as books,
between the front-passenger seat and the
center console or the front-passenger door.
R do not slide the front-passenger seat
backwards against any hard objects.
R sit with the seat belt fastened correctly and
in a position that is as upright as possible
with your back against the backrest.
R while seated, an occupant should not
position him/herself in such a way as to
cause the occupant's weight to be lifted
from the seat bottom as this may result in
the OCS being unable to correctly
approximate the occupant's weight
category.
R read and observe all warnings in this
chapter.
System self-test
The 42 indicator lamp
illuminates when you:
R turn the SmartKey to position 1 or 2 in the
ignition lock
R press the KEYLESS-GO Start-Stop button
once or twice
If an adult occupant is properly sitting on the
passenger seat and the OCS classifies the
occupant as an adult, the 42
indicator lamp illuminates and goes out again
after approximately 6 seconds.
If the seat is not occupied and the OCS
classifies the front-passenger seat as being
unoccupied, the 42 indicator
lamp will illuminate and not go out.
GWarning!
If the 4 2 indicator lamp does
not illuminate, the system is not functioning.
You must contact an authorized Mercedes-
Benz Center before seating any child on the
front passenger seat.
For more information, see "Problems with the
occupant classification system"
( Y page 47).
GWarning
Never place anything between seat cushion
and child seat (e.g. a pillow), since it reduces
the effectiveness of the OCS. The underside
and rear side child restraint system must be
placed entirely on the seat cushion and the
backrest of the front-passenger seat
backrest.
Occupant safety45SafetyBA 164.1 USA, CA Edition B 2011; 1; 2, en-USd2mskotVersion: 3.0.3.52010-04-21T17:25:06+02:00 - Seite 45Z

GWarning
If the 42 indicator lamp does not illuminate or remains out with the weight of a
typical 12-month-old child in a standard child restraint or less, or is unoccupied, on the front-
passenger seat, do not transport a child on the front-passenger seat until the system has been
repaired.
BabySmart™ air bag deactivation
system
How the air bag deactivation system
functions
The BabySmart™ system is standard
equipment in Canada.
GWarning
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 always secure children in the
rear seats. Regardless of the seat position,
children under 12 years must be secured
correctly in a suitable infant or child restraint
system or booster seat suitable for the size
and weight of the child.
Secure the child restraint system with:
R the seat belt of the vehicle
R the seat belt and a Top Tether belt
R the ISOFIX child seat securing system and
a Top Tether belt.
The child restraint system must be installed
and secured correctly, observing the
manufacturer's installation instructions.
Occupants, in particular children, must sit as
upright as possible, fasten the seat belt
correctly and use a suitable infant restraint
system, child restraint system or booster seat
suitable for the size and weight of the child.
Children can be killed or seriously injured by
an inflating air bag. Observe the following
important information if it is necessary to
carry a child on the front-passenger seat:
R Canada only: children under 12 years may
only sit in the front-passenger seat if they
are seated in a child restraint system which
is compatible with BabySmart™ and
approved by Mercedes-Benz. When the
child restraint system is installed correctly,
the front-passenger front air bag is disabled
in conjunction with the BabySmart™
system installed in the vehicle. If the front-
passenger front air bag is deployed in the
event of a collision, it could hit the child.
This could lead to serious or fatal injuries.
R a child in a rear-facing child restraint on the
passenger seat will be seriously injured or
even killed if the passenger front air bag
inflates in a collision which could occur
under some circumstances, even with the
air bag technology installed in your vehicle.
The only way to completely rule out this risk
is by making sure you never place a child in
a rearward-facing child restraint system on
the front-passenger seat. For this reason,
we strongly advise that you always carry
children in a rearward-facing child restraint
system on a rear seat.
R if it is necessary to install a BabySmart™-
compatible rearward-facing child restraint
system on the front-passenger seat, make
sure the 42 indicator lamp is
illuminated. This indicates that the front-
passenger front air bag is disabled. If the
42 indicator lamp does not
light up or goes out when the child restraint
system is installed, check the anchorages
of the restraint system. Check the
42 indicator lamp regularly
while driving to ensure that the
42 indicator lamp is
illuminated. If the 42 indicator
lamp goes out or remains out, you may only48Occupant safetySafety
BA 164.1 USA, CA Edition B 2011; 1; 2, en-USd2mskotVersion: 3.0.3.52010-04-21T17:25:06+02:00 - Seite 48

carry a child on the front-passenger seat
once the system has been repaired.
A child in a rear-facing child restraint on the
passenger seat will be seriously injured or
even killed if the passenger front air bag
inflates.
R when securing a child in a front-facing child
restraint system on the front-passenger
seat, you must:
- move the front-passenger seat as far
back as possible
- use a child restraint system that is
suitable for the age, size and weight of
the child
- observe the manufacturer's installation
instructions in order to install and secure
the child restraint system correctly.GWarning
When using a BabySmart™-compatible child
restraint system on the front-passenger seat,
the front-passenger front air bag is only
disabled if the 42 indicator lamp
is illuminated.
Always check the 42 indicator
lamp if you are using a BabySmart™-
compatible child restraint system on the
front-passenger seat. If the 42
indicator lamp does not light up or goes out
when the child restraint system is installed,
check the anchorages of the restraint system.
If the 42 indicator lamp remains
out, do not use the BabySmart™ child
restraint system to carry a child on the front-
passenger seat until the system has been
repaired.
GWarning
The BabySmart™ air bag disabling system
ONLY works with specially adapted child
restraint systems. It does not work with child
restraint systems that are not compatible with
BabySmart™.
Never place anything between the seat
cushion and the child restraint system (e.g. a
cushion), as this reduces the effectiveness of
the BabySmart™ air bag deactivation system.
The underside of the child restraint system
must lie against the seat cushion of the front-
passenger seat. In the event of an accident,
an incorrectly installed child restraint system
could injure the child instead of offering
protection.
Observe the manufacturer's instructions
when installing special child restraint
systems.
Special child restraint systems which are
compatible with BabySmart™ are necessary
for deactivating the front-passenger front air
bag. When the special child restraint system
which is compatible with BabySmart™ is
installed correctly and is recognized by the
sensor system in the front-passenger seat,
the front-passenger front air bag is
deactivated. In this case, 42
indicator lamp : illuminates. If you have any
questions regarding the special child
restraint systems which are compatible with
BabySmart™, consult an authorized
Mercedes-Benz Center.
If the key has been removed from the ignition
lock or is in position 0, indicator lamp
42 : does not light up.
The system does not disable:
R the side impact air bag
R the window curtain air bag
R the Emergency Tensioning Device/belt
buckle tensioner (ETD)
Occupant safety49SafetyBA 164.1 USA, CA Edition B 2011; 1; 2, en-USd2mskotVersion: 3.0.3.52010-04-21T17:25:06+02:00 - Seite 49Z

of having to swerve to avoid an obstacle at
a speed above 85 mph (140 km/h).
PRE-SAFE ®
takes the following measures
depending on the hazardous situation
detected:
R the front seat belts are pre-tensioned.
R on vehicles with memory functions: the
front-passenger seat is adjusted if it is in an
unfavorable position under accident
conditions.
R if the vehicle skids, the side windows are
closed so that only a small gap remains.
R on vehicles with sliding sunroof: if the
vehicle skids, the sliding sunroof closes so
that only a small gap remains.
If the hazardous situation passes without
resulting in an accident, PRE-SAFE ®
slackens
the belt pretensioning. All settings made by
PRE-SAFE ®
can then be reversed.
If the seat belts are not released:XMove the backrest or the seat back slightly
until the belt pretensioning is reduced.
The locking mechanism releases.GWarning
Make sure that nobody can become trapped
as you adjust the seat.
! Make sure that there are no objects in the
footwell or behind the seats when resetting
the seats. There is a risk that the seats
and/or the objects could be damaged.
More information about belt adjustment, a
convenience function integrated into PRE-
SAFE ®
, can be found in the "Belt adjustment"
section ( Y page 56).
NECK-PRO head restraints
The NECK-PRO head restraints increase
protection to the driver's and front-
passenger's head and neck. To this end, the
head restraints on the driver's and front-
passenger seats are moved forwards and
upwards in the event of a rear-end collision of
a certain severity. This provides better head
support.GWarning
Do not secure any objects (e.g. coat hangers)
on the NECK-PRO head restraints. Otherwise,
the NECK-PRO head restraints may not
function properly, or in the event of a rear-end
collision may not be able offer the level of
protection they are designed to provide.
GWarning
Only use seat covers/head restraint covers
that have been tested and approved by
Mercedes-Benz for your model.
Using seat covers and head restraint covers
other than those recommended can prevent/
impair the triggering of NECK-PRO head
restraints and/or the deployment of side
impact air bags in the front.
Contact an authorized Mercedes-Benz Center
for availability.
If the NECK-PRO head restraints have been
triggered in an accident, you must reset the
NECK-PRO head restraints on the driver’s and
front-passenger seat ( Y page 53).
Otherwise, the additional protection will not
be available in the event of another rear-end
collision. You can recognize when NECK-PRO
head restraints have been triggered by the
fact that they have moved forwards and can
no longer be adjusted.
GWarning!
For your protection, drive only with properly
positioned head restraints.
Adjust the head restraint so that it is as close
to the head as possible and the center of the
head restraint supports the back of the head
at eye level. This will reduce the potential for
injury to the head and neck in the event of an
accident or similar situation.
52Occupant safetySafety
BA 164.1 USA, CA Edition B 2011; 1; 2, en-USd2mskotVersion: 3.0.3.52010-04-21T17:25:06+02:00 - Seite 52

Belt warning for driver and front
passenger
Regardless of whether the driver's and front-
passenger seat belts have already been
fastened, the 7 seat belt warning lamp
lights up for six seconds each time the engine
is started. It then goes out once the driver and
the front passenger have fastened their seat
belts.
If the driver's seat belt is not fastened after
the engine is started, an additional warning
tone will sound. The warning tone goes out
after approximately six seconds or once the
driver's seat belt is fastened.
If after six seconds the driver or front-
passenger have not fastened their seat belts
and the doors are closed:
R the 7 seat belt warning lamp remains
illuminated as long as either the driver's or
front-passenger seat belt is not fastened.
R if the vehicle speed once exceeds 15 mph
(25 km/h), the 7 seat belt warning
lamp lights up. Additionally, a warning tone
will sound with increasing intensity for a
maximum of 60 seconds or until the
driver's and front-passenger seat belt are
fastened.
If the driver/front passenger unfasten their
seat belt while the vehicle is in motion, the
7 seat belt warning lamp lights up and a
warning tone sounds again.
The warning tone ceases even if the driver or
front passenger have still not fastened their
seat belt after 60 seconds. The 7 seat belt
warning lamp stops flashing but continues to
be illuminated.
After the vehicle has come to a standstill, the
warning tone is reactivated and the 7 seat
belt warning lamp flashes again if the vehicle
speed has exceeded 15 mph (25 km/h).
The 7 seat belt warning lamp only goes
out if:
R both the driver and the front passenger
have fastened their seat belts
or
R the vehicle is stationary and a door is open
i For more information on the 7 seat
belt warning lamp, see "Indicator and
warning lamps in the instrument cluster,
seat belt" ( Y page 248).
Emergency Tensioning Devices and
seat belt force limiters
The front seat belts and the outer seat belts
in the rear are equipped with ETDs and belt
force limiters. In addition, the front seat belts
are installed with belt buckle tensioners.
! If the front-passenger seat is not
occupied, do not engage the seat belt
tongue in the buckle on the front-
passenger seat. Otherwise, the Emergency
Tensioning Device/belt buckle tensioner
could be triggered in the event of an
accident.
ETDs/belt buckle tensioners tighten the seat
belts in an accident, pulling them close
against the body.
ETDs/belt buckle tensioners do not correct
incorrect seat positions or incorrectly
fastened seat belts.
ETDs do not pull vehicle occupants back
towards the backrest.
Seat belt force limiters, when activated, are
employed to help reduce the force exerted by
the seat belts on occupants during a crash.
The front belt force limiters are synchronized
with the front air bags, which take on a part
of the deceleration force. Thus, the force
exerted on the occupant is distributed over a
greater area.
The ETDs/belt buckle tensioners can only be
activated when:
R the ignition is switched on
R the restraint systems are operational; see
"SRS warning lamp" ( Y page 36)
Occupant safety57SafetyBA 164.1 USA, CA Edition B 2011; 1; 2, en-USd2mskotVersion: 3.0.3.52010-04-21T17:25:06+02:00 - Seite 57Z

Rthe belt tongue is engaged in the buckle on
each of the three-point seat belts in the
front
R the front-passenger seat is occupied and
the belt tongue is engaged in the buckle on
the front-passenger side.
The ETDs on the outside seats in the rear
compartment are triggered independently of
the lock status of the seat belts.
The ETDs are triggered depending on the type
and severity of an accident:
R in the event of a head-on or rear-end
collision if the vehicle decelerates or
accelerates rapidly in a longitudinal
direction during the initial stages of the
impact
R in the event of a side impact, on the side
opposite the impact if the vehicle
decelerates or accelerates rapidly in a
lateral direction
R in certain situations if the vehicle overturns
and the system determines that it can
provide additional protection.
If the ETDs/belt buckle tensioners are
triggered, you will hear a bang and a small
amount of powder may also be released. Only
in rare cases will the bang affect your hearing.
The powder that is released generally does
not constitute a health hazard. The + SRS
warning lamp lights up.
i If the belt buckle tensioners have been
triggered on the front seats, the buckle will
be pulled down and will be almost flush with
the upper edge of the seat. The + SRS
warning lamp is lit.GWarning
The belt buckle tensioners on the front seats
only function if the belt buckles can be pulled
down unobstructed. They must not be
restricted in any way. Therefore, do not grab
the belt buckles and do not place any objects
under the belt buckles. Otherwise, the
tensioning of the belt by the buckle is
restricted or will not function, and will not
provide any additional protection.
GWarning
Pyrotechnical ETDs/belt buckle tensioners
that were activated must be replaced.
For your safety, when disposing of the
pyrotechnic ETDs/belt buckle tensioners
always follow our safety instructions. These
instructions are available from any authorized
Mercedes-Benz Center.
The PRE-SAFE ®
system is equipped with
electrically reversible pre-tensioners that do
not need replacing after deployment.
Children in the vehicle
Important safety guidelines
GWarning
When leaving the vehicle, always remove the
SmartKey from the ignition lock. Always take
the SmartKey with you and lock the vehicle.
Do not leave children unattended in the
vehicle, even if they are secured in a child
restraint system, or with access to an
unlocked vehicle. A child's unsupervised
access to a vehicle could result in an accident
and/or serious personal injury. The children
could:
R injure themselves on parts of the vehicle
R be seriously or fatally injured through
excessive exposure to extreme heat or cold
R injure themselves or cause an accident with
vehicle equipment that can be operated
even if the SmartKey is removed from the
ignition lock or removed from the vehicle,
such as seat adjustment, steering wheel
adjustment, or the memory function
If children open a door, they could injure other
persons or get out of the vehicle and injure
themselves or be injured by following traffic.
Do not expose the child restraint system to
direct sunlight. The child restraint system's
metal parts, for example, could become very
hot, and the child could be burned on these
parts.
58Children in the vehicleSafety
BA 164.1 USA, CA Edition B 2011; 1; 2, en-USd2mskotVersion: 3.0.3.52010-04-21T17:25:06+02:00 - Seite 58