
BabySmart™ air bag deactivation
system
How the air bag deactivation system
functions
The BabySmart™ system is standard
equipment in Canada.
GWarning
According to accident statistics, children are
safer when properly restrained on the rear
seats than on the front-passenger seat. For
this reason, Mercedes-Benz strongly advises
that you always secure children in the rear
seats. Regardless of seating position, children
12 years old and under must be seated and
properly secured in an appropriately sized
child restraint system or booster seat
recommended for the size and weight of the
child.
Secure the infant restraint system or child
restraint system, using:
R the vehicle's seat belt
R the seat belt and a Top Tether belt
R the LATCH-type (ISOFIX) child seat mount
and a Top Tether belt
The child restraint system must be installed
and secured correctly, observing the
manufacturer's installation instructions.
Occupants, especially children, should always
sit as upright as possible, wear the seat belt
properly and use an appropriately sized infant
restraint, toddler restraint, or booster seat
recommended 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 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. If the child restraint
system is installed properly, the front-
passenger front air bag is deactivated in
conjunction with the BabySmart™ system.
Otherwise, the child could be struck by the
air bag when it inflates in a crash. This could
lead to serious or fatal injury.
R A child in a rear-facing child restraint on the
front-passenger seat will be seriously
injured or even killed if the front-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 means to eliminate
this risk completely is never to place a child
in a rear-facing child restraint in the front-
passenger seat. We therefore strongly
recommend that you always place a child
in a rear-facing child restraint on the rear
seat.
R If it is necessary to install a BabySmart™-
compatible rear-facing child restraint
system on the front-passenger seat, make
sure the 45 indicator lamp is
illuminated. This indicates that the front-
passenger front air bag is deactivated. If the
45 indicator lamp does not light up
or goes out when the child restraint system
is installed, check the anchorages of the
restraint system. Periodically check the
45 indicator lamp while driving to
make sure the 45 is illuminated. If
the 45 indicator lamp goes out or
remains out, do not transport a child on the
front-passenger seat until the system has
been repaired.
A child in a rear-facing child restraint on the
front-passenger seat will be seriously48Occupant safetySafety
BA 212 USA, CA Edition B 2011; 1; 5, en-USdimargiVersion: 3.0.3.62010-05-20T13:33:46+02:00 - Seite 48

injured or even killed if the front-passenger
front air bag inflates.
R If you have to place a child in a forward-
facing child restraint system on the front-
passenger seat, you must:
- move the seat as far back as possible
- use the proper child restraint
recommended for the age, size and
weight of the child
- secure child restraint with the vehicle's
seat belt according to the child seat
manufacturer's instructionsGWarning
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.
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 45 indicator lamp is
illuminated.
Check the 45 indicator lamp
repeatedly, every time you use a
BabySmart™-compatible child restraint
system on the front-passenger seat. Should
the 45 indicator lamp not illuminate
or go out while the restraint is installed,
please check installation. If the 45
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.
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, 45 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
45 : does not light up.
The system does not deactivate:
R the side impact air bag
R the pelvis air bag
R the window curtain air bag
R the Emergency Tensioning Devices
Occupant safety49SafetyBA 212 USA, CA Edition B 2011; 1; 5, en-USdimargiVersion: 3.0.3.62010-05-20T13:33:46+02:00 - Seite 49Z

System self-test
The 45 indicator lamp illuminates
when you:
R turn the SmartKey to position 1 or 2 in the
ignition lock
R on vehicles with KEYLESS-GO, press the
Start-Stop button once or twice
The 45 indicator lamp goes out again
after approximately six seconds.
If the 45 indicator lamp does not
illuminate or is lit continuously, the system is
malfunctioning. Before transporting a child
on the front-passenger seat, have the
BabySmart™ system checked at an
authorized Mercedes-Benz Center.
For more information, see "Problems with the
air bag deactivation system" section
( Y page 51)
GWarning
Do not place powered-on laptops, mobile
phones, electronic tags such as those used in
ski passes or similar electronic devices on the
front passenger seat. Signals from such
devices may interfere with the BabySmart™
air bag deactivation system. Such signal
interference may cause the 45
indicator lamp not to come on during self-test.
The 6 SRS indicator lamp and/or the
45 indicator lamp could be
continuously lit, indicating that the system is
not functioning. The front-passenger front air
bag could deploy inadvertently or fail to
deploy in an accident.
50Occupant safetySafety
BA 212 USA, CA Edition B 2011; 1; 5, en-USdimargiVersion: 3.0.3.62010-05-20T13:33:46+02:00 - Seite 50

Problems with the air bag deactivation systemProblemPossible causes/consequences and M SolutionsThe 45
indicator lamp
illuminates and
remains illuminated.A special BabySmart™ compatible child restraint system is
installed on the front-passenger seat.
The front-passenger front air bag is therefore deactivated.A BabySmart™-compatible child restraint system is not installed
on the front-passenger seat. The BabySmart™ system is
malfunctioning.XHave the BabySmart™ system checked as soon as possible at
an authorized Mercedes-Benz Center.GWarning
If the 45 indicator lamp illuminates and remains illuminated when the weight of a typical
adult or someone larger than a small individual has been detected on the passenger seat, do not
allow any occupant to use the passenger seat until the system has been repaired.
ProblemPossible causes/consequences and M SolutionsThe 45
indicator lamp does not
illuminate or does not
remain illuminated with
a BabySmart™-
compatible child
restraint system
properly installed on
the front-passenger
seat.The BabySmart™ system is malfunctioning.XMake sure there is nothing between the seat cushion and the
child seat.XCheck the installation of the child restraint system.XIf the 45 indicator lamp does not illuminate, have the
BabySmart™ system checked as soon as possible at an
authorized Mercedes-Benz Center.
Do not transport a child on the front-passenger seat until the
child seat recognition system has been repaired.PRE-SAFE ®
systemGWarning
The PRE-SAFE ®
system reduces the impact of
an accident on vehicle occupants, as long as
their seat belts have been fastened correctly.
Although your vehicle is equipped with a PRE-
SAFE ®
system, the possibility of injury in the
event of an accident cannot be ruled out. You
should therefore always drive carefully and
adapt your driving style to the prevailing road,
weather and traffic conditions.
PRE-SAFE ®
takes pre-emptive measures to
protect the occupants in certain hazardous
situations.
PRE-SAFE ®
intervenes:
R in emergency braking situations, e.g. if BAS
is activated or, on vehicles with DISTRONIC
PLUS, if BAS PLUS or PRE-SAFE ®
Brake
intervenes powerfully
R if the radar sensor system detects an
imminent danger of collision in certainOccupant safety51SafetyBA 212 USA, CA Edition B 2011; 1; 5, en-USdimargiVersion: 3.0.3.62010-05-20T13:33:46+02:00 - Seite 51Z

XSlide the belt sash guide downwards.XRelease belt sash guide release : and
make sure that the belt sash guide has
engaged.
Using the seat belt on the center rear
seat
If the left-hand rear seat backrest is folded
down and back up again, the rear center seat
belt may lock. The seat belt can then not be
pulled out.
XTo unlock the rear center seat belt: pull
the seat belt out approximately 1 in
(25 mm) from the belt outlet on the seat
backrest and release again.
The seat belt is retracted and released.
Releasing seat belts
XPress release button ? (Y page 55) and
guide belt tongue ; back towards belt
sash guide :.
!
Make sure that the seat belt is fully rolled
up. Otherwise, the seat belt or belt tongue
will be trapped in the door or in the seat
mechanism. This could damage the door,
the door trim panel and the seat belt.
Damaged seat belts can no longer fulfill
their protective function and must be
replaced. Consult an authorized Mercedes-
Benz Center.
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 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 remains
illuminated.
After the vehicle comes to a standstill, the
warning tone is reactivated and the 7 seat
belt warning lamp flashes again if the vehicle
speed again exceeds 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 264).
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.
Occupant safety57SafetyBA 212 USA, CA Edition B 2011; 1; 5, en-USdimargiVersion: 3.0.3.62010-05-20T13:33:46+02:00 - Seite 57Z

! 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 could be triggered in the
event of an accident.
The ETDs tighten the seat belts in an accident,
pulling them close against the body.
ETDs 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 can only be activated if:
R the ignition is switched on.
R the restraint systems are operational; see
"SRS warning lamp" ( Y page 36).
R the belt tongue is engaged in the buckle on
each of the lap-shoulder 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 vehicledecelerates 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 Emergency Tensioning Devices (ETDs)
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 6 SRS
warning lamp lights up.GWarning
Pyrotechnic Emergency Tensioning Devices
that have been deployed must be renewed.
For your safety, when disposing of Emergency
Tensioning Devices, always observe the
safety instructions. These are available from
any authorized Mercedes-Benz Center.
The PRE-SAFE ®
system has electrically
operated reversible pre-tensioners that do
not require replacement after activation.
Children in the vehicle
Important safety notes
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,
58Children in the vehicleSafety
BA 212 USA, CA Edition B 2011; 1; 5, en-USdimargiVersion: 3.0.3.62010-05-20T13:33:46+02:00 - Seite 58

system, child restraint system or booster seat
suitable for the size and weight of the child.
Children can be seriously or even fatally
injured by an air bag deploying. Observe the
following important information if it is
absolutely necessary to carry a child on the
front-passenger seat:
R USA only: Your vehicle is equipped with air
bag technology that is designed to
deactivate the front-passenger front air
bag, when the system on the front-
passenger seat detects the weight of a
typical 12-month old child in a standard
child restraint.
R USA only: For children that weigh more
than a typical 12-month old child, the front-
passenger front air bag can be activated or
deactivated. Always make sure that the
45 indicator lamp is illuminated
indicating that the front-passenger front air
bag is deactivated.
R Canada only: Children 12 years old and
under may ride on the front seat if a
BabySmart™ compatible child restraint
system is installed on the front-passenger
seat. Use only Mercedes-Benz approved
BabySmart™ compatible child restraint
systems. A BabySmart™ compatible child
restraint system will deactivate the front-
passenger front air bag when installed
correctly. The front-passenger front air bag
will not be deactivated if the child restraint
systems that are installed are not
BabySmart™ compatible or if BabySmart™
compatible child restraint systems are not
installed correctly. If the front-passenger
front air bag is deployed in a collision, the
child could be struck by the air bag. This
could lead to serious or fatal injury.
R A child in a rear-facing child restraint on the
front-passenger seat will be seriously
injured or even killed if the front-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 completelyrule 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 you must install a rear-facing child
restraint on the front-passenger seat
because circumstances require you to do
so, make sure the 45 indicator lamp
is illuminated, indicating that the front-
passenger front air bag is deactivated. If the
45 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 45
indicator lamp regularly while driving to
ensure that the 45 indicator lamp is
illuminated. If the 45 indicator lamp
goes out or remains out, you may only carry
a child on the front-passenger seat once
the system has been repaired.
A child in a rear-facing child restraint on the
front-passenger seat will be seriously
injured or even killed if the front-passenger
front air bag inflates.
R when securing a child in a 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
Infants and small children should never share
a seat belt with another occupant. During an
accident, they could be crushed between the
occupant and seat belt.
A child's risk of serious or fatal injuries is
significantly increased if the child restraints
60Children in the vehicleSafety
BA 212 USA, CA Edition B 2011; 1; 5, en-USdimargiVersion: 3.0.3.62010-05-20T13:33:46+02:00 - Seite 60

Example: Sedan
XTo activate: press the child-proof lock
lever up in the direction of arrow :.
XMake sure that the child-proof locks are
working properly.
XTo deactivate: press the child-proof lock
lever down in the direction of arrow ;.
Override feature for the rear side
windows
GWarning
Observe "Important safety notes"
(Y page 58).
GWarning
When children ride on the vehicle's rear seats,
activate the override switch. Otherwise, the
children could be injured, e.g. by trapping
themselves in the rear side window.
XTo activate/deactivate: press button ;.
If indicator lamp : 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 : is off,
operation is possible using the switches in
the rear compartment.
Panic alarm
X To activate: press and hold !
button : for about one second.
An alarm sounds and the exterior lighting
flashes.
XTo deactivate: press ! button :
again.
or
XInsert the SmartKey into the ignition lock.
or
XPress the KEYLESS-GO Start-Stop button.
The KEYLESS-GO key must be in the
vehicle.
iUSA only:
This device complies with the part 15 of the
FCC regulations. Operation is subject to
the following two conditions:
1. This device may not cause interference,
and
2. This device must withstand any
interference received, including
interference that may cause undesired
operation.
Any unauthorized modification to this
device could void the user's authority to
operate the equipment.
iCanada only:
64Panic alarmSafety
BA 212 USA, CA Edition B 2011; 1; 5, en-USdimargiVersion: 3.0.3.62010-05-20T13:33:46+02:00 - Seite 64