2015 MERCEDES-BENZ B-CLASS HATCHBACK ECU

The seat belt system consists of:
R seat belts
R belt tensioners for the front seat belts and the
outer seat belts in the rear
R belt force limiters for the front seat belts and
the outer seat belts in the rear
If the seat belt is pulled quickly or sharply from
the belt outlet, the inertia reel locks. The belt
strap cannot be pulled out any further.
The belt tensioner tightens the seat belt in the
event of a collision so that it fits tightly across
your body. However, it does not pull the vehicle
occupants back in the direction of the seat
backrest.
The belt tensioner does not, however, correct an incorrect seat position or correct the routing of
a seat belt that is worn incorrectly.
When triggered, seat belt force limiters help to
reduce the peak force exerted by the seat belt
on the vehicle occupant.
The belt force limiters on the front seats are
synchronised with the front airbags, which take
on a part of the deceleration force. This can
reduce the forces to which the vehicle occu-
pants are subjected during an accident.
! If the co-driver's seat is not occupied, do not
engage the seat belt tongue in the buckle on
the co-driver's seat. Otherwise, the belt ten-
sioner could be triggered in the event of an
accident and would have to be replaced.
Important safety notes G
WARNING
The seat belt cannot perform its intended pro- tective function if it is not fastened correctly. Also, an improperly fastened seat belt can
cause additional injuries in the event of an
accident, sudden braking or abrupt changes
of direction. There is an increased risk of
injury, possibly even fatal.
Always make sure that all vehicle occupants
are wearing their seat belt properly and are
seated correctly. G
WARNING
The seat belt does not offer the intended level of protection if you have not moved the back-
rest to an almost vertical position. When brak- ing or in the event of an accident, you could
slide underneath the seat belt and sustain
abdomen or neck injuries, for example. This
poses an increased risk of injury or even fatal
injury.
Adjust the seat properly before beginning
your journey. Always ensure that the backrestis in an almost vertical position and that the
shoulder section of your seatbelt is routed
across the centre of your shoulder. G
WARNING
Persons under 1.50 mtall cannot wear the
seat belts correctly without a suitable, addi-
tional restraint system. The seat belt cannot
perform its intended protective function if it is not fastened correctly. Also, an improperly
fastened seat belt can cause additional inju-
ries in the event of an accident, sudden brak-
ing or abrupt changes of direction. There is an increased risk of injury, possibly even fatal.
Secure persons less than 1.50 mtall in a suit-
able restraint system.
If a child younger than twelve years old and
under 1.50 m in height is travelling in the vehi-
cle: R always secure the child in a child restraint
system suitable for this Mercedes-Benz vehi-
cle. The child restraint system must be appro- priate to the age, weight and size of the child.
R always observe the instructions and safety
notes on the automatic front-passenger front
airbag deactivation system (Y page 42)
R always observe the instructions and safety
notes on "Children in the vehicle" in this Own- er's Manual (Y page 49) in addition to the
child restraint system manufacturer's instal-
lation instructions G
WARNING
Seat belts cannot protect as intended, if:
R they are damaged, have been modified, are
extremely dirty, bleached or dyed
R the seat belt buckle is damaged or
extremely dirty
R modifications have been made to the belt
tensioners, belt anchorages or inertia reels 36
Occupant safetySafety

Seat belts may sustain non-visible damage in
an accident, e.g. due to glass splinters. Modi-
fied or damaged seat belts can tear or fail, for example in the event of an accident. Modified
seat belt tensioners may be deployed unin-
tentionally or fail to be deployed when
required. There is an increased risk of injury,
possibly even fatal.
Never modify safety belts, seat belt tension-
ers, seat belt anchorages and inertia reels.
Ensure that seat belts are not damaged or
worn and are clean. After an accident, have
the seat belts checked immediately at a quali- fied specialist workshop.
Mercedes-Benz recommends that you only use
seat belts which have been approved specifi-
cally for your vehicle by Mercedes-Benz. Other- wise, your vehicle's general operating permit
could be invalidated.
Correct seat belt use Observe the safety notes on the seat belt
(Y
page 36).
All vehicle occupants must be wearing the seat
belt correctly before beginning the journey. Also make sure that all vehicle occupants are always
wearing the seat belt correctly while the vehicle is in motion.
When fastening the seat belt, always make sure
that:
R the seat belt tongue is only inserted into the
belt buckle belonging to that seat
R the seat belt is tight across your body
Avoid wearing bulky clothing, e.g. a winter
coat.
R the seat belt is not twisted
Only then can forces which occur be distrib-
uted across the surface of the seat belt.
R the shoulder section of the belt is always
routed across the centre of your shoulder
The shoulder section of the seat belt should
not touch your neck nor be routed under your
arm. If possible, adjust the seat belt to the
appropriate height.
R the lap belt passes across your lap as tightly
and as low down as possible
The lap belt must always be routed across
your hip joints and never across your abdo- men. This applies particularly to pregnant
women. If necessary, press the lap belt down
into your hip joints and pull tight with the
shoulder section of the belt.
R the seat belt is not routed across sharp, poin-
ted or fragile objects
If you have such items located on or in your
clothing, e.g. pens, keys or spectacles, store
these in a suitable place.
R only one person is using a seat belt
Infants and children must never travel sitting
on the lap of a vehicle occupant. In the event
of an accident, they could be crushed
between the vehicle occupant and seat belt.
R objects are never secured with a seat belt if
the seat belt is also being used by one of the
vehicle's occupants
Also ensure that no objects are placed
between a person and the seat. e.g. a cush-
ion.
Seat belts are only intended to secure and
restrain vehicle occupants. Always observe the
"Loading guidelines" for securing objects, lug-
gage or loads (Y page 224).
Fastening and adjusting the seat belts Observe the safety notes on the seat belt
(Y
page 36) and the information on the correct
use of the seat belt (Y page 37).
If a passenger is wearing the centre rear seat
belt, also observe the information on the seat
belt for the centre rear seat (Y page 38). Basic illustration Occupant safety
37Safety Z

board, for example. Your feet may otherwise
be in the deployment area of the airbag.
R Always secure persons less than 1.50 mtall in
suitable restraint systems. Up to this height,
the seat belt cannot be worn correctly.
If a child is travelling in your vehicle, also
observe the following notes:
R Always secure children under twelve years of
age and less than 1.50 mtall in suitable child
restraint systems.
R Child restraint systems should be fitted to the
rear seats.
R Only secure a child to the front-passenger
seat when the front-passenger front airbag is
disabled, and only then in a rearward-facing
child restraint system. If the PASSENGER AIR BAG OFF indicator lamp is permanently lit, the
front-passenger front airbag is disabled
(Y page 35).
R Always observe the instructions and safety
notes on the automatic front-passenger front
airbag deactivation system (Y page 42) and
on "Children in the vehicle" (Y page 49) in
addition to the child restraint system manu-
facturer's installation instructions.
Objects in the vehicle interior may prevent
the airbag from functioning correctly. Before
starting your journey and to avoid risks resulting
from the speed of the airbag as it deploys, make sure that:
R there are no people, animals or objects
between the vehicle occupants and an airbag.
R there are no objects between the seat, door
and B-pillar.
R no hard objects, e.g. coat hangers, are hang-
ing on the grab handles or coat hooks.
R no accessories, such as cup holders, are
attached to the vehicle within the deployment
area of an airbag, e.g. to doors, side windows, rear side trim or side walls.
R no heavy, sharp-edged or fragile objects are in
the pockets of your clothing. Store such
objects in a suitable place. G
WARNING
If you modify an airbag cover or affix objects
such as stickers to it, the airbag can no longer function correctly. There is an increased risk
of injury.
Never modify an airbag cover or affix objects
to it. G
WARNING
Sensors to control the airbags are located in
the doors. Modifications or work not per-
formed correctly to the doors or door panel-
ling, as well as damaged doors, can lead to the function of the sensors being impaired. The
airbags might therefore not function properly any more. Consequently, the airbags cannot
protect vehicle occupants as they are
designed to do. This poses an increased risk
of injury.
Never modify the doors or parts of the doors.
Always have work on the doors or door pan-
elling carried out at a qualified specialist
workshop.
Front airbags !
Do not place heavy objects on the front-
passenger seat. This could cause the system
to identify the seat as being occupied. In the
event of an accident, the restraint systems on
the front-passenger side may be triggered
and have to be replaced. Driver's airbag
:deploys in front of the steer-
ing wheel. Front-passenger front airbag ;
deploys in front of and above the glove com-
partment.
When deployed, the front airbags offer addi-
tional head and thorax protection for the occu-
pants in the front seats.
The PASSENGER AIR BAG OFF and PASSENGER
AIR BAG ON indicator lamps inform you about
the status of the front-passenger front airbag
(Y page 35). 40
Occupant safetySafety

The indicator lamps display the status of the
front-passenger front airbag:
R PASSENGER AIR BAG ON lights up: the front-
passenger front airbag is enabled. If, in the
event of an accident, all deployment criteria
are met, the front-passenger front airbag is
deployed.
R PASSENGER AIR BAG OFF lights up: the front-
passenger front airbag is disabled. It will then
not be deployed in the event of an accident.
If the status of the front-passenger front airbag
changes while the vehicle is in motion, an airbag display message appears in the instrument clus-
ter (Y page 199). When the front-passenger
seat is occupied, always pay attention to the
PASSENGER AIR BAG ON and PASSENGER AIR
BAG OFF indicator lamps. Be aware of the status of the front-passenger front airbag both before
and during the journey.
If a person sits in the passenger seat, they must
be:
R seated with the seat belt fastened correctly
R in an almost upright position with their back
against the seat backrest
R with their feet resting on the floor, if possible
If the front passenger does not observe these
conditions, the automatic front-passenger front
airbag deactivation system may be influenced,
e.g. because the front passenger:
R transfers their weight by supporting them-
selves on a vehicle armrest
R sits in such a way that their weight is raised
from the seat cushion
The front-passenger front airbag may be disa-
bled by mistake as a result of these or similar
actions. In this case, the PASSENGER AIR BAG
OFF indicator lamp lights up permanently. The
front-passenger front airbag does not then
deploy during an accident. G
WARNING
If the PASSENGER AIRBAG OFF indicator lamp is lit, the front-passenger front airbag is disa-
bled. It will not be deployed in the event of an
accident and cannot perform its intended pro-
tective function. A person in the front-
passenger seat could then, for example, come
into contact with the vehicle's interior, espe-
cially if the person is sitting too close to the
dashboard. This poses an increased risk of
injury or even fatal injury. When the front-passenger seat is occupied,
always make sure that:
R the classification of the person in the front-
passenger seat is correct and that the front- passenger front airbag is enabled or disa-
bled in accordance with the person in the
front-passenger seat.
R the front-passenger seat has been moved
back as far back as possible.
R the person is seated correctly.
Make sure, both before and during the jour-
ney, that the status of the front-passenger
front airbag is correct. G
WARNING
If you secure a child on the co-driver's seat in a rearward-facing child restraint system and
the PASSENGER AIR BAG ON indicator lamp
lights up, the co-driver's airbag could be
deployed in the event of an accident. The childcould be struck by the airbag. There is an
increased risk of injury, possibly even fatal.
In this case, always ensure that the co-driver's
airbag is disabled. The PASSENGER AIRBAG
OFF indicator lamp must light up.
If the PASSENGER AIR BAG OFF indicator lamp
remains off and/or the PASSENGER AIR BAG
ON indicator lamp lights up, do not install a rear- ward-facing child restraint system on the front-
passenger seat. Further information can be
found under "Problems with the automatic front-
passenger front airbag deactivation system"
(Y page 46). G
WARNING
If you secure a child in a forward-facing child
restraint system on the front-passenger seat
and you position the front-passenger seat too close to the dashboard, in the event of an
accident, the child could:
R come into contact with the vehicle's inte-
rior if the PASSENGER AIR BAG OFF indi-
cator lamp is lit, for example
R be struck by the airbag if the PASSENGER
AIR BAG ON indicator lamp is lit Occupant safety
43Safety
Z

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 1.50 m in height is travelling in the vehi-
cle:
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 always pay attention to the instructions and
safety notes on the automatic front-
passenger front airbag deactivation system
(Y page 42). G
WARNING
If children are left unsupervised in the vehicle, they could:
R open doors, thereby endangering other per-
sons or road users
R get out and be struck by oncoming traffic
R operate vehicle equipment and become
trapped, for example
In addition, the children could also set the
vehicle in motion by, for example:
R releasing the parking brake
R shifting the transmission out of park posi-
tion P
R starting the vehicle's drive system
There is a risk of an accident and injury.
When leaving the vehicle, always take the key with you and lock the vehicle. Never leave
children and animals unattended in the vehi-
cle. Keep the keys out of the reach of children. G
WARNING
If persons (particularly children) are exposed
to heat or cold for a prolonged period, there is a risk of serious or even fatal injuries. Never
leave persons (particularly children) unatten-
ded in the vehicle. G
WARNING
If the child restraint system is placed in direct sunlight, the parts could become very hot.
Children could be suffer burns by touching
these parts, in particular on the metallic parts
of the child restraint system. There is a risk of injury.
If you and your child leave the vehicle, always
make sure that the child restraint system is
not in direct sunlight. Cover it with a blanket, for example. If the child restraint system has
been exposed to direct sunlight, leave it to
cool down before securing the child in it.
Never leave children unattended in the vehi-
cle.
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 36) and the information on the correct
use of the seat belt (Y page 37). Child restraint system
If you fit a rearward-facing child restraint system
to the centre rear seat, the rear arm rest must be folded back as far as possible.
Observe the instructions for correct use of the
child restraint system (Y page 54).
For safety reasons, Mercedes-Benz recom-
mends that you only use a child restraint system
recommended by Mercedes-Benz
(Y page 58). G
WARNING
If the child restraint system is incorrectly fit-
ted on the seat position suitable for this pur-
pose, it cannot perform its intended protec-
tive function. In the event of an accident, Children in the vehicle
49Safety
Z

sharp braking or a sudden change in direction,
the child may not be held securely. There is an
increased risk of serious or even fatal injuries.
Observe the manufacturer's installation
instructions and the correct use for the child
restraint system. Make sure that the entire
surface of the child restraint system is resting
on the seat surface. Never place objects
under or behind the child restraint system,
e.g. cushions. Only use child restraint sys-
tems with the original cover designed for
them. Only replace damaged covers with gen- uine covers. G
WARNING
If the child restraint system is fitted 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 fit child restraint systems properly,
even if they are not being used. Make sure
that you observe the child restraint system
manufacturer's installation instructions.
You will find further information on stowing
objects, luggage and loads securely under
"Loading guidelines" (Y page 224).G
WARNING
Child restraint systems or their securing sys-
tems that have been damaged or subjected to a load in an accident cannot perform their
intended protective function. In the event of
an accident, sharp braking or a sudden
change in direction, the child may not be held securely. There is an increased risk of serious
or even fatal injuries.
Immediately replace child restraint systems
that have been damaged or subjected to a
load in an accident. Have the child restraint
securing systems checked in a qualified spe-
cialist workshop before fitting a child restraint
system again. The securing systems of child restraint systems
are:
R the seat belt system
R the ISOFIX or i-Size securing rings
R the Top Tether anchorages
If it is absolutely necessary to fit a child restraint system to the front-passenger seat, always
observe the information on "Child restraint sys-
tems on the front-passenger seat"
(Y page 52).
Observe the warning labels in the vehicle inte-
rior and on the child restraint system.
i It is advisable to use Mercedes-Benz care
products to clean child restraint systems rec- ommended by Mercedes-Benz. You can
obtain information about this at any
Mercedes-Benz Service Centre. ISOFIX and i-Size child restraint sys-
tems
G
WARNING
ISOFIX child restraint systems or i-Size child
restraint systems do not offer sufficient pro-
tection for children whose weight is greater
than 22 kg, who are secured using the safety belt integrated in the child restraint system.
The child could, for example, not be restrained
correctly in the event of an accident. This
poses an increased risk of injury or even fatal
injury.
If the child weighs more than 22 kg, only use
ISOFIX child restraint systems or i-Size 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.
When fitting a child restraint system, be sure to
observe the manufacturer's installation and
operating instructions and the instructions for
correct use of the child restraint system
(Y page 54).
Before every trip, make sure that the ISOFIX
child restraint system is engaged correctly in
both ISOFIX securing rings. 50
Children in the vehicleSafety

This symbol indicates an ISOFIX position which
is suitable for attaching an ISOFIX child restraint system. A similar symbol can be found on the
ISOFIX child restraint system. This symbol indicates an i‑Size position which is
suitable for attaching an i-Size child restraint
system. A similar symbol can be found on the i- Size child restraint system.
! When fitting the child restraint system,
make sure that the seat belt for the centre
seat does not get trapped. Otherwise, the
seat belt could be damaged. :
ISOFIX securing rings ;
i-Size securing rings
X Install the ISOFIX child restraint system on
both ISOFIX securing rings :or i-Size secur-
ing rings ;.
or
X Install the i-Size child restraint system on both
i-Size securing rings ;.
ISOFIX and i-Size are standardised securing sys-
tems for special child restraint systems. ISOFIX child restraint systems are approved in accord-
ance with ECE R-44. i-Size child restraint sys-
tems are approved in accordance with ECE
R-129.
Only child restraint systems that have been
approved in accordance with ECE R-44 may be
attached to ISOFIX securing rings. i-Size child
restraint systems that have been approved in
accordance with ECE R-44 and ECE R-129 may
be attached to i-Size securing rings. ISOFIX
securing ring :or i-Size securing ring ;are
installed on the left and right sides of the rear
seats. Top Tether
Introduction Top Tether provides an additional connection
between the child restraint system secured with
ISOFIX and the vehicle. It helps reduce the risk
of injury even further. If the child restraint sys-
tem is fitted 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- Children in the vehicle
51Safety
Z

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 fitting a Top Tether belt. Observe the lock verificationindicator. Adjust the rear seat backrests so
that they are in an upright position.
If the rear backrest is not engaged and locked,
the red lock verification indicator will be visible
(Y page 228).
Top Tether anchorages The Top Tether anchorage points are located on
the rear side of the backrests on both outer rear seats. X
Move head restraint :upwards.
X Release rear seat backrest =and fold it for-
wards (Y page 228).
X Route Top Tether belt Bunder head
restraint :between the two head restraint
bars. X
Hook Top Tether hook Aof Top Tether belt
B into Top Tether anchorage ?.
Ensure that:
R Top Tether hook Ais hooked into Top
Tether anchorage ?as shown
R Top Tether belt Bis not twisted
R Top Tether belt Bis routed between rear
seat backrest =and luggage compart-
ment cover ;if luggage compartment
cover ;is fitted
R Top Tether belt Bis routed between the
rear seat backrest =and the safety net if
the safety net is fitted
X Swing back rear seat backrest =until it
engages.
The red lock verification indicator is no longer visible.
X Fit the ISOFIX child restraint system with Top
Tether. Always comply with the child restraint
system manufacturer's installation instruc-
tions when doing so.
X Tension Top Tether belt B. Always comply
with the child restraint system manufactur-
er's installation instructions when doing so.
X If necessary, move head restraint :back
down again slightly (Y page 89). Make sure
that you do not interfere with the correct rout-
ing of Top Tether belt B. Child restraint system on the front-
passenger seat
General 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.
Vehicles with the automatic front-passenger
front airbag deactivation system: if it is abso-
lutely necessary to fit a child restraint system tothe front-passenger seat, always observe the
information on the "Automatic front-passenger
front airbag deactivation system" (Y page 42).52
Children in the vehicleSafety