2017 MERCEDES-BENZ B-Class length

passenger front air bag 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 air bag is correct. G
WARNING
If you secure a child in a rearward-facing child
restraint system on the front-passenger seat
and the PASSENGER AIR BAG OFF indicator
lamp is off, the front-passenger front air bag
may deploy in the event of an accident. The
child could be struck by the air bag. This poses an increased risk of injury or even fatal injury.
Make sure that the front-passenger front air
bag has been disabled. The PASSENGER AIR
BAG OFF indicator lamp must be lit.
If the PASSENGER AIR BAG OFF indicator lamp
stays off, do not install a rearward-facing child
restraint system on the front-passenger seat.
You can find more information on OCS under
"Problems with the Occupant Classification Sys-
tem" (Y page 49). 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 air bag if the PASSENGER
AIR BAG OFF indicator lamp is off
This poses an increased risk of injury or even fatal injury.
Always move the front-passenger seat as far
back as possible and fully retract the seat
cushion length. Always make sure that the
shoulder belt strap is correctly routed from
the vehicle belt sash guide to the shoulder belt guide on the child restraint system. The
shoulder 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
accordingly. Always observe the child
restraint system manufacturer's installation
instructions.
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 twelve 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 even in the case of a twelve-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 indi-
cates that the front-passenger front air bag is activated. The result of the classification is
dependent on, among other factors, the child
restraint system and the child's stature. It is
recommended that you install the child
restraint system on a suitable rear seat.
R the front-passenger seat is occupied by a per-
son 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. Alternatively, a per-
son of smaller 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 adult stature, the
PASSENGER AIR BAG OFF indicator lamp
goes out after the system self-test. This indi-
cates that the front-passenger front air bag is
activated. Occupant safety
47Safety Z

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 per-
son of a stature corre-
sponding to that of an
adult. The classification of the person on the front-passenger seat is incor-
rect.
X Make sure the conditions for a correct classification of the person
on the front-passenger seat are met (Y page 46).
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 seatis:
R unoccupied
R occupied with the
weight of a child up to
twelve months old in achild restraint system 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
forward-facing child restraint system must lie as flat as possible
against the backrest of the front-passenger seat. If necessary,
adjust the position of the front-passenger seat.
X Make sure that the seat cushion length is fully retracted.
X When installing the child restraint system, make sure that the seat
belt is tight. Do not pull the seat belt tight using the front-passenger seat adjustment. This could result in the seat belt and the child
restraint system being pulled too tightly.
X Check for correct 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 accord-
ingly.
X Make sure that no objects are applying additional weight onto the
seat.
X 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 child restraint system on the front-passenger seat. It is recom-
mended that you install the child restraint system on a suitable rear
seat.
X Have OCS checked as soon as possible at an authorized Mercedes-
Benz Center. 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 your
passenger to have deployed air bags replaced 50
Occupant safetySafety

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. Fully
retract the seat cushion length. 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 lie as flat as possible against the backrest of the
front-passenger seat. The child restraint system must not touch the roof or be subjected to a loadby the head restraint. Adjust the angle of the
seat backrest and the head restraint position
accordingly. Always make sure that the shoul-
der belt strap is correctly routed from the vehi-
cle belt outlet to the shoulder belt guide on the
child restraint system. The shoulder belt strap
must be routed forwards and downwards from
the vehicle belt outlet. If necessary, adjust the
vehicle belt outlet and the front-passenger seat
accordingly.
Always observe the child restraint system man- ufacturer's installation and operating instruc-
tions. Child-proof locks
Important safety notes G
WARNING
If children are traveling in the vehicle, they
could:
R open doors, thus endangering other people
or road users
R exit the vehicle and be caught by oncoming
traffic
R operate vehicle equipment and become
trapped
There is a risk of an accident and injury.
Always activate the child-proof locks and
override feature if children are traveling in the vehicle. When leaving the vehicle, always take
the key with you and lock the vehicle. Never
leave children unattended in the vehicle.
Override feature for:
R the rear doors (Y page 58)
R the rear side windows (Y page 58) 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 transmission out of park position
P.
R start the vehicle's drive system.
They could also operate the vehicle's equip-
ment. 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. Children in the vehicle
57Safety Z

X
Reach under the right-hand side of trim 0084
and lightly tug along the entire length of the
trim in order to unclip 0083it.
X Pull out connector 006Bof the surround lighting
by releasing the latches.
X Place paneling 0084to one side. X
On the side where the bulb is to be replaced,
unclip the remaining part of trim 006Cfrom the
assembly with a strong tug, until the bulb
holder is accessible. X
Remove bulb holder 006Dusing both sides of
lever 006E. Bulb holder X
Backup lamp 006F: pull the bulb out of bulb
holder 006D.
X Insert the new bulb into the bulb holder.
X Rear fog lamp 0070: press the bulb gently into
bulb holder 006D, turn it counter-clockwise and
remove it from the bulb holder.
X Insert the new bulb into the bulb holder and
turn it clockwise.
X Reinsert the bulb holder until you hear it
engage audibly.
X Position paneling 006Cand engage it in place by
tapping it with your hand.
X Before continuing with the installation, check
that all the metal clips are inserted in the parts placed to one side: 2 clips 0044in the upper part
of handle 0087and 5 clips 0083in paneling 0084.
X If not, remove the missing metal clips from
the metal openings in the tailgate and insert
them in the appropriate places.
X Take paneling 0084and connect plug connector
006B to the surround lighting.
i The surround lighting only illuminates when
the tailgate has been shut and reopened.
X Position paneling 0084and engage it in place by
tapping it with your hand, starting from the
outside.
X Clip in the lower section of handle 0043at posi-
tion 0044again.
X Insert the upper section of handle 0087into
lower section 0043and engage with recess 0085
again.
License plate lamp X
Switch off the lights.
X Open the tailgate.
X Apply a screwdriver to lamp lens 0043from the
outside. 94
Replacing bulbsLights and windshield wipers

Electric parking brake
General notes 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 transmission out of park position
P.
R start the vehicle's drive system.
They could also operate the vehicle's equip-
ment. 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.
The function of the electric parking brake and
the parking lock is dependent on the on-board
voltage. If the on-board voltage is low or if there is a malfunction in the system:
R it may not be possible to apply the released
parking brake
R it may no longer be possible to shift the trans-
mission to position P
X If this is the case, only park the vehicle on
level ground and secure it to prevent it rolling away.
X Shift the transmission to position P.
It may not be possible to release an applied
parking brake if the on-board voltage is low or
there is a malfunction in the system. Contact a
qualified specialist workshop.
The electric parking brake carries out a function check at regular intervals when the drive system
is switched off. The sounds that can be heard
while this is occurring are normal. Applying or releasing manually X
To engage: push handle 0043.
When the electric parking brake is applied,
the red 0049(USA only) or 0024(Canada
only) indicator lamp lights up in the instru-
ment cluster.
The electric parking brake can also be applied when the SmartKey is removed.
X To release: pull handle0043.
The red 0049(USA only) or 0024(Canada
only) indicator lamp in the instrument cluster
goes out.
The electric parking brake can only be
released:
R when the SmartKey is in position 1or 2in
the ignition lock (Y page 109) or
R if the ignition was switched on using the
Start/Stop button
Applying automatically When the vehicle's HOLD function is holding the
vehicle at a standstill, the electric parking brake is engaged automatically.
In addition, at least one of the following condi-
tions must be fulfilled:
R the drive system is switched off.
R the driver is not wearing a seat belt and the
driver's door is opened
R there is a system malfunction
R the power supply is insufficient
R the vehicle is stationary for a lengthy period
The red 0049(USA only) or 0024(Canada only)
indicator lamp in the instrument cluster lights
up. 130
ParkingDriving and parking

(200 km/h) range. If ATTENTION ASSIST
detects typical indicators of fatigue or increas-
ing lapses in concentration on the part of the
driver, it suggests taking a break.
Important safety notes ATTENTION ASSIST is only an aid to the driver. It
might not always recognize fatigue or increasing inattentiveness in time or fail to recognize them
at all. The system is not a substitute for a well-
rested and attentive driver.
The functionality of ATTENTION ASSIST is
restricted and warnings may be delayed or not
occur at all:
R if the length of the journey is less than approx-
imately 30 minutes
R if the road condition is poor, e.g. if the surface
is uneven or if there are potholes
R if there is a strong side wind
R if you have adopted a sporty driving style with
high cornering speeds or high rates of accel-
eration
R if you are predominantly driving slower than
37 mph (60 km/h) or faster than 125 mph
(200 km/ h)
R if the time has been set incorrectly
R in active driving situations, such as when you
change lanes or change your speed
ATTENTION ASSIST is reset when you continue
your journey and starts assessing your tiredness
again if:
R you switch off the engine
R you take off your seat belt and open the driv-
er's door, e.g. for a change of drivers or to
take a break
Displaying the attention level You can have current status information dis-
played in the assistance menu (Y
page 162) of
the on-board computer.
X Select the Assistance display for Attention
Assist using the on-board computer
(Y page 162).
The following information is displayed: R Length of the journey since the last break.
R The Attention Attention Level
Leveldetermined by ATTEN-
TION ASSIST, displayed in a bar display in five levels from high to low
R If ATTENTION ASSIST is unable to calculate
the attention level and cannot output a warn-
ing, the System Passive System Passive message appears.
The bar display then changes the display,
such as when you are driving at a speed below 37 mph (60 km/h) or above 124 mph
(200 km/h).
Activating ATTENTION ASSIST X
Activate ATTENTION ASSIST using the on-
board computer (Y page 163).
The system determines the attention level of
the driver depending on the setting selected:
Standard Standard selected: the sensitivity with which
the system determines the attention level is set to normal.
Sensitive
Sensitive selected: the sensitivity is set
higher. The attention level detected by Attention
Assist is adapted accordingly and the driver is
warned earlier.
When ATTENTION ASSIST is deactivated, the
00D7 symbol appears in the multifunction dis-
play in the assistance graphic display.
When ATTENTION ASSIST has been deactivated,
it is automatically reactivated after the engine
has been stopped. The sensitivity selected cor-
responds to the last selection activated (stand-
ard/sensitive).
Warning in the multifunction display If fatigue or increasing lapses in concentration
are detected, a warning appears in the multi-
function display:
ATTENTION ASSIST ATTENTION ASSIST Take a
Take a
Break!
Break!.
In addition to the message shown in the multi-
function display, you will then hear a warning
tone. Driving systems
149Driving and parking Z

R
It is particularly important to observe the
described order when connecting and dis-
connecting the jumper cables.
R Never connect or disconnect the battery
terminals while the engine is running. G
WARNING
Battery acid is caustic. There is a risk of injury. Avoid contact with skin, eyes or clothing. Do
not inhale any battery gases. Do not lean over
the battery. Keep children away from batter-
ies. Wash away battery acid immediately with
plenty of clean water and seek medical atten- tion. H
Environmental note Batteries contain dangerous
substances. It is against the
law to dispose of them with
the household rubbish. They
must be collected separately
and recycled to protect the
environment. Dispose of batteries in an
environmentally friendly
manner. Take discharged
batteries to a qualified spe-
cialist workshop or a special
collection point for used bat-
teries.
! Have the battery checked regularly at a
qualified specialist workshop.
Observe the service intervals in the Mainte-
nance Booklet or contact a qualified specialist workshop for more information.
Comply with safety precautions and take pro-
tective measures when handling batteries. Risk of explosion.
Fire, open flames and smoking are
prohibited when handling the bat-
tery. Avoid creating sparks. Battery acid is caustic. Avoid contact
with skin, eyes or clothing.
Wear suitable protective clothing,
especially gloves, apron and face-
guard.
Rinse any acid spills immediately
with clear water. Contact a physician if necessary. Wear eye protection.
Keep children away.
Observe this Operator's Manual.
For safety reasons, Mercedes-Benz recom-
mends that you only use batteries which have
been tested and approved for your vehicle by
Mercedes-Benz. These batteries provide
increased impact protection to prevent vehicle
occupants from suffering acid burns should the battery be damaged in the event of an accident.
In order for the battery to achieve the maximum possible service life, it must always be suffi-
ciently charged.
Like other batteries, the vehicle battery may
discharge over time if you do not use the vehicle.In this case, have the battery disconnected at a
qualified specialist workshop. You can also
charge the battery with a charger recommended by Mercedes-Benz. Contact a qualified special-
ist workshop for further information.
Have the battery condition of charge checked
more frequently if you use the vehicle mainly for
short trips or if you leave it standing idle for a
lengthy period. Consult a qualified specialist
workshop if you wish to leave your vehicle
parked for a long period of time.
Only replace a battery with a battery that has
been recommended by Mercedes-Benz.
Remove the SmartKey if you park the vehicle
and do not require any electrical consumers.
The vehicle will then use very little energy, thus conserving battery power.
After an interruption to the power supply, such
as due to a discharged battery, you must reset
the clock via the multimedia system. You can Batteries
247Breakdown assistance Z

R
It is particularly important to observe the described order when connecting and disconnecting
the jumper cables.
R Never connect or disconnect the battery terminals while the engine is running. G
WARNING
A discharged battery can freeze at temperatures below freezing point. When jump-starting the
vehicle or charging the battery, gases can escape from the battery. There is a risk of an explosion.
Allow the frozen battery to thaw out before charging it or jump-starting.
! Avoid repeated and lengthy starting attempts.
Do not use a rapid-charging device to start the engine.
If the indicator/warning lamps do not light up in the instrument cluster at low temperatures, it is very likely that the discharged battery has frozen. In this case you may neither jump-start the vehicle norcharge the battery. The service life of a thawed-out battery may be shorter. Have the thawed-out
battery checked at a qualified specialist workshop.
If the 12 V battery is discharged, or after the vehicle has been jump-started, the Service
Service
Required Required Do
DoNot
Not Shift
Shift Gears
GearsVisit
VisitDealer
Dealer message appears. There is a malfunction in the
on-board voltage. Visit a qualified specialist workshop immediately.
The drive system cannot be started if the 12 V battery is discharged. This is not dependent on
whether the high-voltage battery is charged or not. The vehicle cannot be jump-started if the high-
voltage battery is discharged. The high-voltage battery must be charged first.
The drive system can be started using another vehicle. R Only use batteries with an equal nominal voltage (12 volts).
R Make sure that the battery of the donor vehicle does not have a significantly lower capacity than
the discharged battery.
R Use jumper cables with a sufficient cross-section and insulated terminal clamps from a qualified
specialist workshop, e.g. an authorized Mercedes-Benz Center.
R Make sure that the two vehicles do not touch.
R Route the jumper cables so that they cannot be caught by rotating components in the engine
compartment.
R Do not disconnect the discharged battery from the vehicle's electrical system. 250
Jump-startingBreakdown assistance