2015 MERCEDES-BENZ B-CLASS HATCHBACK check engine

Pre-entry climate control via key
(on-board computer) ......................1
85
Problem with the rear window
heating .......................................... 120
Problems with cooling with air
dehumidification ............................ 117
Setting the air distribution ............. 117
Setting the air vents ..................... .123
Setting the airflow ......................... 118
Setting the temperature ................ 117
Switching air-recirculation mode
on/off ............................................ 120
Switching on/off ........................... 116
Switching residual heat on/off ...... 122
Switching the rear window heat-
ing on/off ...................................... 119
Switching the ZONE function on/
off ................................................. .118
THERMOTRONIC (2-zone) auto-
matic climate control ..................... 115
Cockpit
Overview .......................................... 25
COLLISION PREVENTION ASSIST
PLUS
Activating/deactivating ................. 183
Display message ............................ 196
Operation/notes .............................. 62
COMAND
Generated electricity ..................... 137
COMAND display
Cleaning ......................................... 246
Combination switch ............................ 99
Consumption statistics (on-board
computer) .......................................... 176
Convenience closing feature .............. 83
Convenience opening feature ............ 83
Convenience opening/closing (air-
recirculation mode) ........................... 120
Coolant (engine)
Checking the level ......................... 240
Important safety notes .................. 283
Cooling
see Climate control
Copyright ............................................. 24
Cornering lamps
Changing bulbs .............................. 106 Cornering light function
Display message ............................ 201
Function/notes ............................ .100
Crash-responsive emergency light-
ing ....................................................... 103
Cruise control
Activation conditions ..................... 151
Cruise control lever ....................... 151
Deactivating ................................... 152
Display message ............................ 207
Driving system ............................... 150
Important safety notes .................. 151
LIM indicator lamp ......................... 151
Selecting ........................................ 151
Setting a speed .............................. 152
Storing and maintaining current
speed ............................................. 151
Cup holder
Centre console .............................. 233
Important safety notes .................. 233
Rear compartment ......................... 234 D
Data see Technical data
Daytime driving lights
Display message ............................ 202
Function/notes ................................ 98
Switching on/off (on-board com-
puter) ............................................. 186
Dealership
see Qualified specialist workshop
Declarations of conformity ................. 22
Departure time
Setting (on-board computer) .......... 184
Diagnostics connection ......................22
Digital speedometer .........................178
Dipped-beam headlamps
Changing bulbs .............................. 105
Display message ............................ 201
Setting for driving abroad (sym-
metrical) .......................................... 97
Setting for driving on the right/
left ................................................. 187
Switching on/off .............................. 98
DIRECT SELECT lever
Transmission ................................. 129 6
Index

High-voltage switch-off device
!
The vehicle's high-voltage electrical system
must only be switched off when the vehicle is stationary by specially trained technicians.
The vehicle's high-voltage electrical system
may otherwise be damaged. Your vehicle is equipped with a high-voltage
switch-off device :which can be used to
switch off the vehicle's high-voltage electrical
system.
Mobile phone aerial !
It is not permitted to retrofit a mobile phone
aerial.
trailer tow hitch !
It is not permitted to retrofit a trailer cou-
pling.
Warning Vehicles with an electric motor generate signif-
icantly less noise than vehicles with internal
combustion engines. As a result, your vehicle
may not be heard by other road users until it is
very close to them, or it may not be heard at all.
This is particularly the case if other road users
have not yet seen your vehicle but are instead
relying on hearing. Drive with particular care,
allowing for the possibility that other road users may behave unpredictably.
The vehicle can be equipped with a sound gen-
erator. The sound generator is activated so that
other road users can hear your vehicle better.
The sound generator is activated at speeds
under 30 km/h and switches off automatically
at higher speeds. Declarations of conformity
Wireless vehicle components The following information applies to all compo-
nents of the vehicle and the information sys-
tems and communication devices integrated
into the vehicle which receive and/or transmit
radio waves:
The components of this vehicle that receive
and/or transmit radio waves are compliant with
the basic requirements and all other relevant
conditions of Directive 1999/5/EC. You can
obtain further information from any Mercedes-
Benz Service Centre.
Electromagnetic compatibility The electromagnetic compatibility of the vehicle
components has been checked and certified
according to the currently valid version of Reg-
ulation ECE-R 10. Diagnostics connection
The diagnostics connection is only intended for
the connection of diagnostic equipment at a
qualified specialist workshop. G
WARNING
If you connect equipment to a diagnostics
connection in the vehicle, it can affect the
operation of the vehicle systems. This may
affect the operating safety of the vehicle.
There is a risk of an accident.
Do not connect any equipment to a diagnos-
tics connection in the vehicle. 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 22
Introduction

allows you to continue steering the vehicle when
braking.
The ! ABS warning lamp in the instrument
cluster lights up when the ignition is switched
on. It goes out when the engine is running.
ABS works from a speed of about 8 km/h,
regardless of road-surface conditions. ABS
works on slippery surfaces, even when you only
brake gently.
Important safety notes i
Observe the "Important safety notes" sec-
tion (Y page 61). G
WARNING
If ABS is faulty, the wheels could lock when
braking. The steerability and braking charac-
teristics may be severely impaired. Addition-
ally, further driving safety systems are deac-
tivated. There is an increased danger of skid- ding and accidents.
Drive on carefully. Have ABS checked imme-
diately at a qualified specialist workshop.
If ABS is malfunctioning, other systems, includ-
ing driving safety systems, will also become
inoperative. Observe the information on the ABS warning lamp (Y page 216) and display mes-
sages which may be shown in the instrument
cluster (Y page 190).
Brakes X
If ABS intervenes: continue to depress the
brake pedal with force until the braking sit-
uation is over.
X To make a full brake application: depress
the brake pedal with full force.
If ABS intervenes when braking, you will feel a
pulsing in the brake pedal.
The pulsating brake pedal can be an indication
of hazardous road conditions; this serves as a
reminder to take extra care while driving. BAS (Brake Assist)
General notes BAS operates in emergency braking situations.
If you depress the brake pedal quickly, BAS
automatically boosts the braking force, thus
shortening the stopping distance.
Important safety notes i
Observe the "Important safety notes" sec-
tion (Y page 61). G
WARNING
If BAS is malfunctioning, the braking distance
in an emergency braking situation is
increased. There is a risk of accident.
In an emergency braking situation, depress
the brake pedal with full force. ABS prevents
the wheels from locking.
Braking X
Keep the brake pedal depressed firmly until
the emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will function as usual once you
release the brake pedal. BAS is deactivated. COLLISION PREVENTION ASSIST
PLUS
General notes i
Observe the "Important safety notes" sec-
tion (Y page 61).
COLLISION PREVENTION ASSIST PLUS consists of a distance warning function with an autono-
mous braking function and Adaptive Brake
Assist.
COLLISION PREVENTION ASSIST PLUS can help you to minimise the risk of a collision with the
vehicle in front or reduce the effects of such a
collision.
If COLLISION PREVENTION ASSIST PLUS
detects that there is a risk of a collision, you will
be warned visually and acoustically. If you do not react to the visual and audible collision warning,autonomous braking can be initiated in critical
situations. If you apply the brake yourself in a 62
Driving safety systemsSafety

G
WARNING
Adaptive Brake Assist does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R when cornering
As a result, the Adaptive Brake Assist may not intervene in all critical conditions. There is a
risk of an accident.
Always pay careful attention to the traffic sit- uation and be ready to brake.
Due to the nature of the system, particularly
complicated but non-critical driving conditions
may also cause Brake Assist to intervene.
If Adaptive Brake Assist is not available due to a malfunction in the radar sensor system, the
brake system remains available with full brake
boosting effect and BAS. Adaptive brake lights
The adaptive brake lights warn following traffic
in an emergency braking situation:
R by flashing brake lamps
R the hazard warning lamps are activated
If you brake sharply from a speed of more than
50 km/h or if braking is assisted by BAS or BAS
PLUS, the brake lamps flash rapidly. In this way,
traffic travelling behind you is warned in an even more noticeable manner.
If you brake sharply from a speed of more than
70 km/h to a standstill, the hazard warning
lamps are activated automatically. If the brakes
are applied again, the brake lamps light up con- tinuously. The hazard warning lamps switch off
automatically if you travel faster than 10 km/h. You can also switch off the hazard warning
lamps using the hazard warning button
(Y page 100). ESP
®
(Electronic Stability Program)
General notes i
Observe the "Important safety notes" sec-
tion (Y page 61). ESP
®
monitors driving stability and traction, i.e.
power transmission between the tyres and the
road surface.
If ESP ®
detects that the vehicle is deviating from
the direction desired by the driver, one or more
wheels are braked to stabilise the vehicle. The
engine output is also modified to keep the vehi- cle on the desired course within physical limits.
ESP ®
assists the driver when pulling away on
wet or slippery roads. ESP ®
can also stabilise
the vehicle during braking.
ETS (Electronic Traction System) i
Observe the "Important safety notes" sec-
tion (Y page 61).
ETS traction control is part of ESP ®
.
Traction control brakes the drive wheels indi-
vidually if they spin. This enables you to pull
away and accelerate on slippery surfaces, for
example if the road surface is slippery on one
side. In addition, more drive torque is transfer-
red to the wheel or wheels with traction.
Traction control remains active if you deactivate
ESP ®
.
Important safety notes i
Observe the "Important safety notes" sec-
tion (Y page 61). G
WARNING
If ESP ®
is malfunctioning, ESP ®
is unable to
stabilise the vehicle. In addition, other driving
safety systems are switched off. This increa-
ses the risk of skidding and an accident.
Drive on carefully. Have ESP ®
checked at a
qualified specialist workshop.
When towing your vehicle with the front axle
raised, observe the notes on ESP ®
(Y page 262).
When towing your vehicle away with the rear
axle raised, observe the notes on ESP ®
(Y page 262).
If the å ESP®
OFF warning lamp lights up
continuously, ESP ®
is deactivated.
If the ÷ ESP®
warning lamp and the å
warning lamp are lit continuously, ESP ®
is not
available due to a malfunction. Driving safety systems
65Safety 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

or traffic conditions. SPEEDTRONIC is only an
aid. You are responsible for the distance to the
vehicle in front, for vehicle speed, for braking in
good time, and for staying in lane.
If there is a change of drivers, advise the new
driver of the speed stored.
Variable SPEEDTRONIC General notes
:
To activate or increase speed
; LIM indicator lamp
= To activate at the current speed/last stored
speed
? To activate or reduce speed
A To switch between cruise control and varia-
ble SPEEDTRONIC
B To deactivate cruise control
You can operate cruise control and variable
SPEEDTRONIC with the cruise control lever.
The LIM indicator lamp on the cruise control
lever indicates which system you have selected:
R LIM indicator lamp off: cruise control is
selected
R LIM indicator lamp on: variable SPEED-
TRONIC is selected
When the engine is running, you can use the
cruise control lever to limit the speed to any
speed between 30 km/h and the technically
permitted maximum speed of the vehicle.
Selecting variable SPEEDTRONICX Check whether LIM indicator lamp ;is on.
If it is on, variable SPEEDTRONIC is already
selected. If it is not, press the cruise control lever in the
direction of arrow A.
LIM indicator lamp ;in the cruise control
lever lights up. Variable SPEEDTRONIC is
selected.
Storing the current speed You can use the cruise control lever to limit the
speed to any speed above 30 km/h while the
engine is running.
X Briefly press the cruise control lever up :or
down ?.
The current speed is stored and shown in the multifunction display.
Storing or calling up the speed G
WARNING
If you call up the stored speed and it is lower
than the current speed, the vehicle deceler-
ates. If you do not know the stored speed, the vehicle could decelerate unexpectedly. There
is a risk of an accident.
Pay attention to the road and traffic condi-
tions before calling up the stored speed. If you do not know the stored speed, store the
desired speed again.
X Briefly pull the cruise control lever towards
you =.
Setting a speed
X To adjust the set speed in 10 km/h incre-
ments: briefly press the cruise control lever
up : beyond the pressure point for a higher
speed, or down ?for a lower speed.
or X Keep the cruise control lever pressed beyond
the pressure point until the desired speed is
set. Press the cruise control lever up :for a
higher speed or down ?for a lower speed.
X To adjust the set speed in 1 km/h incre-
ments:
briefly press the cruise control lever
up : to the pressure point for a higher speed
or down ?for a lower speed.
or X Keep the cruise control lever pressed to the
pressure point until the desired speed is set.
Press the cruise control lever up :for a
higher speed or down ?for a lower speed. Driving systems
153Driving and parking Z

Display messages
Possible causes/consequences and
M
MSolutions ì
Malfunction Visit Malfunction Visit
workshop workshop Malfunctions are present in the drive system and/or in the cooling
system.
X Consult a qualified specialist workshop immediately. Without starting Without starting
engine again, con‐ engine again, con‐
sult workshop sult workshop The vehicle's high-voltage electrical system is malfunctioning. A warn-
ing tone also sounds.
X Do not switch off the drive system.
X Consult a qualified specialist workshop immediately. ì
Stop Switch engine Stop Switch engine
off off There is a serious malfunction in the drive system. A warning tone also
sounds.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.
X Do not tow the vehicle.
X Consult a qualified specialist workshop immediately. Driving systems
Display messages
Possible causes/consequences and
M MSolutions À
Attention Assist: Attention Assist:
Take a break! Take a break! Based on certain criteria, ATTENTION ASSIST has detected fatigue or
a lack of concentration on the part of the driver. A warning tone also
sounds.
X If necessary, take a break.
During long journeys, take regular breaks in good time so that you get
enough rest. À
Attention Assist Attention Assist
inoperative inoperative ATTENTION ASSIST is inoperative.
X Consult a qualified specialist workshop. ë
Off Off The HOLD function is deactivated. The vehicle is skidding.
A warning tone also sounds.
X Reactivate the HOLD function later (Y page 154). The HOLD function is deactivated. When the brake pedal is firmly
depressed, an activation condition is not fulfilled.
A warning tone also sounds.
X Check the activation conditions for the HOLD function
(Y page 154). Display
messages
205On-board computer and displays Z

X
Make sure that the windscreen wipers are
switched off.
X Pull release lever :on the bonnet.
The bonnet is released. X
Reach into the gap between the bonnet and
the radiator trim and press bonnet catch
lever ;to the left.
X Raise the bonnet. X
Pull support strut ?out of bracket A.
X Lift up support strut ?and insert it into yel-
low retaining clip =.
Closing the bonnet X
Raise the bonnet slightly and, at the same
time, remove support strut ?from yellow
retaining clip =.
X Swing support strut ?down and press it into
bracket Auntil it engages.
X Lower the bonnet and let it fall from a height
of approximately 20 cm.
X Check that the bonnet has engaged properly.
If the bonnet can be raised slightly, it is not
properly engaged. Do not press the bonnet
closed. Open the bonnet again and close it
with a little more force. Checking and adding other service
products
Checking the coolant level G
WARNING
The cooling system is pressurised, particu-
larly when the engine is warm. If you open the cap, you could be scalded if hot coolant
sprays out. There is a risk of injury.
Let the engine cool down before you open the
cap. Wear gloves and eye protection. Open
the cap slowly to release the pressure.
! The coolant level must only be checked and
corrected when the engine has cooled down
(coolant temperature under 40 †). Checking
the coolant level when the coolant tempera-
ture is over 40 † can lead to damage to the
engine or engine cooling system. X
Park the vehicle on a level surface.
Only check the coolant level when the vehicle
is on a level surface and the drive system has
cooled down.
X Turn the key to position 2in the ignition lock
(Y page 126).
X Check the coolant temperature display in the
instrument cluster.
The coolant temperature must be below
40 †.
X Turn the key to position 0in the ignition lock
(Y page 126).
X Slowly turn cap :anti-clockwise to allow
excess pressure to escape.
X Turn cap :further anti-clockwise and
remove it.
If the coolant is at the level of marker bar =
in the filler neck when cold, there is enough
coolant in coolant expansion tank ;.240
Engine compartmentMaintenance and care