2015 MERCEDES-BENZ B-CLASS HATCHBACK ECU

Useful information
i This Owner's Manual describes all models,
series and optional equipment for your vehi-
cle that were available at the time of going to
press. National variations are possible. Note
that your vehicle may not be equipped with all
of the functions described. This is also the
case for systems and functions relevant to
safety.
i Read the information on qualified specialist
workshops: (Y page 23). Key
Important safety notes
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 you attach heavy or large objects to the key, the key could be unintentionally turned in the
ignition lock. This could cause the engine to
be switched off. There is a risk of an accident.
Do not attach any heavy or large objects to the
key. Remove any bulky keyrings before insert-
ing the key into the ignition lock. !
Keep the key away from strong magnetic
fields. Otherwise, the remote control function could be affected.
Strong magnetic fields can occur in the vicin-
ity of powerful electrical installations.
Do not keep the key: R with electronic devices, e.g. a mobile phone
or another key
R with metallic objects, e.g. coins or metal film
R inside metallic objects, e.g. a metal case
Vehicles with KEYLESS-GO start function: do
not keep the key in the luggage compartment.
Otherwise, the key may not be detected, e.g.
when starting the drive system using the Start/
Stop button.
United Kingdom only: G
WARNING
When the double locks are activated, the
doors can no longer be opened from the
inside. People in the vehicle can no longer get out, e.g. in hazardous situations. There is a
risk of injury.
Therefore, do not leave any people unsuper-
vised in the vehicle, particularly children, eld-
erly people or people in need of special assis-
tance. Do not activate the double lock when
people are in the vehicle.
If the vehicle has been locked from the outside, the double lock function is activated as stand-
ard. It is then not possible to open the doors
from inside the vehicle. You can deactivate the
double lock function by deactivating the interior
motion sensor (Y page 69). The doors can then
be opened from the inside after the vehicle has
been locked from the outside. You can open the rear doors from inside the vehicle if they are not
secured by the child-proof locks (Y page 60).
The anti-theft alarm system is triggered if the
door is opened from the inside. Switch off the
alarm (Y page 68). 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. Key
71Opening and closing Z

Doors
Important safety notes
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.
Stow luggage or loads preferably in the luggage compartment. Observe the loading guidelines
(Y page 224).
United Kingdom only: G
WARNING
When the double locks are activated, the
doors can no longer be opened from the
inside. People in the vehicle can no longer get out, e.g. in hazardous situations. There is a
risk of injury.
Therefore, do not leave any people unsuper-
vised in the vehicle, particularly children, eld-
erly people or people in need of special assis-
tance. Do not activate the double lock when
people are in the vehicle.
If the vehicle has been locked with the key, the
double lock function is activated as standard. It
is then not possible to open the doors from
inside the vehicle. You can deactivate the dou-
ble lock function by deactivating the interior
motion sensor (Y page 69). The doors can then
be opened from the inside after the vehicle has been locked from the outside. You can open the
rear doors from inside the vehicle if they are not secured by the child-proof locks (Y page 60).
The anti-theft alarm system is triggered if the
door is opened from the inside. Switch off the
alarm (Y page 68). Unlocking and opening the doors
from the inside
X
Pull door handle ;.
If the door is locked, locking knob :pops up.
The door is unlocked and opens.
For all countries except the United Kingdom:
You can open a door from inside the vehicle
even if it has been locked. You can only open the rear doors from inside the vehicle if they are not secured by the child-proof locks (Y page 60).
If the vehicle has previously been locked with
the key from the outside, opening a door from
the inside will trigger the anti-theft alarm sys-
tem. Switch off the alarm (Y page 68).
United Kingdom only: G
WARNING
When the double locks are activated, the
doors can no longer be opened from the
inside. People in the vehicle can no longer get out, e.g. in hazardous situations. There is a
risk of injury.
Therefore, do not leave any people unsuper-
vised in the vehicle, particularly children, eld-
erly people or people in need of special assis-
tance. Do not activate the double lock when
people are in the vehicle.
If the vehicle has been locked from the outside, the double lock function is activated as stand-
ard. It is then not possible to open the doors 78
DoorsOpening and closing

from inside the vehicle. You can deactivate the
double lock function by deactivating the interior
motion sensor (Y page 69). The doors can then
be opened from the inside after the vehicle has been locked from the outside. You can open the
rear doors from inside the vehicle if they are not
secured by the child-proof locks (Y page 60).
The anti-theft alarm system is triggered if the
door is opened from the inside. Switch off the
alarm (Y page 68). Centrally locking and unlocking the
vehicle from the inside
You can centrally lock or unlock the vehicle from
the inside. This can be useful if you wish to lock the vehicle before pulling away, for example. X
To unlock: press button :.
X To lock: press button ;.
If all the doors and the tailgate are closed, the
vehicle locks.
This does not lock or unlock the charge socket
flap.
You cannot unlock the vehicle centrally from the
inside if the vehicle has been locked with the key or KEYLESS-GO.
For all countries except the United Kingdom:
You can open a door from inside the vehicle
even if it has been locked.
If the vehicle has previously been locked with
the key from the outside, opening a door from
the inside will trigger the anti-theft alarm sys-
tem. Switch off the alarm (Y page 68).
You can open the rear doors from inside the
vehicle if they are not secured by the child-proof locks (Y page 60). When a locked door is opened from inside the
vehicle, the previous unlocking process will be
observed if the vehicle has been:
R locked with the locking button for the central
locking or
R locked automatically
The vehicle will be fully unlocked if it had previ-
ously been fully unlocked. Only the door which
has been opened from the inside is unlocked if
only the driver's door had been previously
unlocked.
Only for the United Kingdom: if the vehicle
has been locked with the key, the double lock
function is activated as standard. It is then not
possible to open the doors from inside the vehi-
cle. You can deactivate the double lock function by deactivating the interior motion sensor
(Y page 69). The doors can then be opened from
the inside after the vehicle has been locked from
the outside. You can open the rear doors from
inside the vehicle if they are not secured by the child-proof locks (Y page 60). The anti-theft
alarm system is triggered if the door is opened
from the inside. Switch off the alarm
(Y page 68).
When a locked door is opened from inside the
vehicle, the previous unlocking process will be
observed if the vehicle has been:
R locked with the locking button for the central
locking or
R locked automatically
The vehicle will be fully unlocked if it had previ-
ously been fully unlocked. Only the door which
has been opened from the inside is unlocked if
only the driver's door had been previously
unlocked. Automatic locking feature Doors
79Opening and closing Z

i
If you lock the vehicle as described above,
the charge socket flap is not locked. The anti-
theft alarm system is not primed. Luggage compartment
Important safety notes
G
WARNING
If objects, luggage or loads are not secured or not secured sufficiently, they could slip, tip
over or be flung around and thereby hit vehicle
occupants. There is a risk of injury, especially when braking or abruptly changing directions.
Always store objects so that they cannot be
flung around. Secure objects, luggage or
loads against slipping or tipping before the
journey.
! The tailgate swings upwards and to the rear
when opened. Therefore, make sure that
there is sufficient clearance above and behind
the tailgate.
The opening dimensions of the tailgate can be
found in the "Vehicle data" section
(Y page 284).
Stow luggage or loads preferably in the luggage
compartment. Observe the loading guidelines
(Y page 224).
Do not leave the key in the luggage compart-
ment. You could otherwise lock yourself out.
The tailgate can be:
R opened and closed manually from outside
R emergency release activated from the inside Opening/closing from the outside
Opening X
Press the %button on the key.
X Pull handle :.
X Raise the tailgate.
Closing X
Pull the tailgate down using handle :.
X Let the tailgate to drop into the lock.
X If necessary, lock the vehicle with the &
button on the key or with KEYLESS-GO. Tailgate emergency release
General notes !
The tailgate swings upwards and to the rear
when opened. Therefore, make sure that
there is sufficient clearance above and behind
the tailgate.
The opening dimensions of the tailgate can be
found in the "Vehicle data" section
(Y page 284). Luggage compartment
81Opening and closing Z

Useful information
i This Owner's Manual describes all models,
series and optional equipment for your vehi-
cle that were available at the time of going to
press. National variations are possible. Note
that your vehicle may not be equipped with all
of the functions described. This is also the
case for systems and functions relevant to
safety.
i Read the information on qualified specialist
workshops: (Y page 23). Running-in notes
In certain driving and driving safety systems, the sensors adjust automatically while a certain dis-
tance is being driven after the vehicle has been delivered or after repairs. Full system effective- ness is not reached until the end of this teach-in
process.
Brake pads/linings and discs that are either new or have been replaced only achieve optimum
braking effect after several hundred kilometres
of driving. Compensate for the reduced braking
effect by applying greater force to the brake
pedal. Driving
Important safety notes
G
WARNING
Objects in the driver's footwell may restrict
the clearance around the pedals or block a
depressed pedal. This jeopardises the oper-
ating and road safety of the vehicle. There is a risk of an accident.
Stow all objects securely in the vehicle so that
they do not get into the driver's footwell.
Always fit the floormats securely and as pre-
scribed in order to ensure that there is always sufficient room for the pedals. Do not use
loose floormats and do not place several floor- mats on top of one another. G
WARNING
Unsuitable footwear can hinder correct usage of the pedals, e.g.:
R shoes with thick soles
R shoes with high heels
R slippers
There is a risk of an accident.
Wear suitable footwear to ensure correct
usage of the pedals. G
WARNING
If you switch off the ignition while driving,
safety-relevant functions are only available
with limitations, or not at all. This could affect, for example, the power steering and the brake
boosting effect. You will require considerably
more effort to steer and brake. There is a risk of an accident.
Do not switch off the ignition while driving. G
WARNING
If the parking brake has not been fully
released when driving, the parking brake can:
R overheat and cause a fire
R lose its hold function.
There is a risk of fire and an accident. Release
the parking brake fully before driving off.
! Before driving away, you must ensure that,
for your own safety and to avoid damage, the charging cable has been removed from the
vehicle socket. Otherwise, you cannot shift
the transmission out of position P.
The braking performance of the electric motor
using recuperative braking is, in some operating modes, either reduced or not effective:
R when the charge status of the high-voltage
battery increases
R if the high-voltage battery is not yet at a nor-
mal operating temperature
R when driving close to the maximum speed
R when the vehicle is almost stationary
R in transmission position N
R during and after ESP stability control
If you do not make an additional effort to apply
the brake yourself, the braking effect may not be Driving
125Driving and parking Z

Drive program S (Sport)
Drive program
Sis characterised by the follow-
ing:
R the vehicle exhibits sporty driving character-
istics
R the entire power output can be utilised by
depressing the accelerator pedal.
E+ (Economy Plus) Drive program
E+is characterised by the fol-
lowing:
R reduced torque and significantly reduced
power. This supports an especially efficient
and even driving style and results in a reduc-
tion in speed to approximately 110 km/h.
R the vehicle pulling away more gently in
forward gear unless the accelerator pedal is
depressed fully.
R the wheels are less likely to spin.
R particularly efficient overrun.
R full power output by using kickdown.
R the performance of the air-conditioning and
heating systems is reduced. Steering wheel gearshift paddles
Manually adjustable recuperation :
Left-hand steering wheel gearshift paddle -
; Right-hand steering wheel gearshift paddle
+
You can increase or reduce recuperation in over-
run mode using the steering wheel gearshift
paddles. When you remove your foot from the
accelerator pedal, recuperation occurs. The
electric motor is then used as a alternator and
energy is recovered while driving. The recuper- ated electrical energy is stored in the high-volt-
age battery. A higher energy recuperation level
means that the vehicle is braked more power-
fully.
If necessary, counteract the reduced regenera-
tive braking effect by applying the brake your-
self.
Information on the Recuperative Braking Sys-
tem (Y page 67).
X To decrease recuperation: pull right-hand
steering wheel gearshift paddle ;.
X To increase recuperation: pull left-hand
steering wheel gearshift paddle :.
The various recuperation levels are shown in the
transmission position display once Dhas been
selected (Y page 129).
The following recuperation levels are available in
overrun mode:
R no recuperation (D +
, coasting mode)
R moderate recuperation ( D)
R high recuperation ( D-
)
R recuperation depending on the traffic situa-
tion (D AUTO
, radar-based)
You can see the intensity of recuperation in
overrun mode by reading the recuperation per-
formance value shown in the power display
(Y page 173).
Every time drive position Dis selected, the
transmission switches into recuperation level
D AUTO
automatically.
The various different levels are to be used under the following conditions: D
+ Driving without much braking and
without the presence of obstacles
or sharp bends
The vehicle retains the maximum
possible amount of kinetic
energy. D
Normal driving132
TransmissionDriving and pa
rking

D
- Sporty driving or driving on a
downhill gradient
The brake pedal does not need to
be used as often because the
extent of the deceleration is
greater than in D.
Energy use when decelerating is
considerably higher than when
the vehicle is braked with the
brake pedal. D
AUTO
(radar-
based) The intensity of recuperation is
automatically adjusted to the cur-
rent traffic situation.
Default setting In levels
Dand D-
, deceleration can be control-
led in an infinitely variable manner using the
accelerator pedal.
The braking performance of the electric motor
using recuperative braking is, in some operating modes, either reduced or not effective:
R when the charge status of the high-voltage
battery increases
R if the high-voltage battery is not yet at a nor-
mal operating temperature
R when driving close to the maximum design
speed
R when the vehicle is almost stationary
R in transmission position N
R during and after ESP stability control
If you do not make an additional effort to apply
the brake yourself, the braking effect may not be sufficient. If necessary, counteract the reduced regenerative braking effect by applying the
brake yourself.
Radar-based recuperation The vehicle uses the sensors of COLLISION PRE-
VENTION ASSIST PLUS during radar-based
recuperation (D AUTO
). The sensors detect the
distance to the vehicle ahead and its speed. The intensity of recuperation is then automatically
adjusted to the current traffic situation.
The range can then be increased by storing
energy efficiently. Adjustment is infinitely vari-
able from overrun mode (no recuperation) to
maximum recuperation.
Maintain sufficient distance to the vehicle in
front. Mercedes-Benz recommends that you activate COLLISION PREVENTION ASSIST PLUS
as a visual and acoustic aid.
Examples of radar-based recuperation:
R Approaching a slower vehicle, a decelerating
vehicle or when following a vehicle downhill.
Your vehicle decelerates slightly and increa-
ses recuperation.
R Driving when no vehicle is detected in front or
when a vehicle is detected in the far distance or an accelerating vehicle is detected. Your
vehicle switches to overrun mode at higher
speeds.
R Driving on a steep downhill slope. Accelera-
tion downhill is reduced and recuperation is
increased. This is comparable with shifting
down when driving downhill.
X To activate radar-based recuperation: pull
steering wheel gearshift paddle :or;
towards you and hold for about one second.
X To deactivate radar-based recuperation:
briefly pull steering wheel gearshift paddle
:
or ; towards you.
If you change between radar-based and manual
recuperation, the following levels are activated
depending on the selection via the steering
wheel gearshift paddles: :
Steering wheel
gearshift paddle - selects
D-
(maximum
recuperation) ;
Steering wheel
gearshift paddle + selects
D+
(overrun) In particular, the function of the radar sensors
can be impaired in the case of:
R
dirt on the sensors or obscured sensors
R snow or heavy rain
R interference by other radar sources
R strong radar reflections, for example, in multi-
storey car parks
R a narrow vehicle travelling in front, e.g. a
motorcycle
R a vehicle travelling in front on a different line
Following damage to the front end of the vehicle, have the radar sensor settings and operation
checked at a qualified specialist workshop
immediately. This also applies to collisions at
slow speeds where there is no visible damage to the front of the vehicle.
If the radar sensors are not available, the system
switches automatically to level Dwith moderate Transmission
133Driving and parking Z

recuperation. Have the radar sensors checked
at a qualified specialist workshop immediately.
Automatic adjustment of recuperation
on downhill gradients The vehicle can detect steep downhill gradients.
To reduce acceleration downhill and to charge
the high-voltage battery, recuperation is
increased steplessly. This is comparable to the
engine brake in a combustion engine when you
downshift a gear on a downhill gradient.
Automatic adjustment of recuperation on down-
hill gradients is available in level DAUTO
or on
vehicles without steering wheel gearshift pad-
dles in level D.
Intelligent recuperation The vehicle uses the map and camera data of
Traffic Sign Assist in addition to the sensors of
COLLISION PREVENTION ASSIST PLUS during
radar-based recuperation ( DAUTO
). The rate of
recuperation is then automatically adjusted to
the current traffic situation, taking the current
and future maximum speed into account. High-voltage battery
Important safety notes
G
DANGER
The vehicle's high voltage electrical system is under high voltage. If you modify components
in the vehicle's high-voltage electrical system or touch damaged components, you may be
electrocuted. The components in the vehi-
cle's high-voltage electrical system may be
damaged in an accident, although the damage
is not visible. There is a risk of fatal injury.
Do not touch any high-voltage components
after an accident and never modify the vehi-
cle's high-voltage electrical system. Have the vehicle towed away after an accident and the vehicle's high-voltage electrical system
checked by a qualified specialist workshop. G
WARNING
In the event of a vehicle fire, the internal pres- sure of the high-voltage battery could exceed a critical value. In this case, flammable gas
escapes through a vent valve in the vehicle's
underbody. The gas can ignite. There is a risk of injury.
Leave the danger area immediately. Secure
the danger area at a suitable distance, whilst
observing legal requirements. G
DANGER
Connecting the charging cable to the mains
supply via incorrectly installed mains sockets or by means of adapters, extension cables or
similar could cause a fire or an electric shock. There is a risk of fatal injury.
To avoid such risks, observe the following:
R Only connect the charging cable to mains
sockets:
- which have been properly installed and
- which have been inspected by a qualified
electrician
R For safety reasons, only use charging
cables which have been supplied with the
vehicle or which have been approved for
this vehicle.
R Never use a damaged charging cable.
R Do not use:
- extension cables
- extension reels
- multi-outlet sockets
R Never use socket adapters to connect the
charging cable to the mains socket. The
only exception is if the adapter has been
tested and approved by the manufacturer
for charging the high-voltage battery of an
electric vehicle.
R Observe the safety notes in the operating
instructions for the socket adapter. G
DANGER
Connecting the charging cable to the wallbox via an incorrectly installed wallbox or adapter,
extension cable or similar could cause a fire or an electric shock. There is a risk of fatal injury. 134
High-voltage batteryDriving and parking