check engine MERCEDES-BENZ B-CLASS 2012 Owners Manual

Automatic transmission
Automatic drive program ............... 144
Changing gear ............................... 143
DIRECT SELECT lever .....................140
Display message
............................ 220
Drive program display ....................141
Driving tips .................................... 143
Emergency running mode ..............147
Engaging drive position .................. 142
Engaging neutral ............................ 141
Engaging reverse gear ................... 141
Engaging the park position ............ 141
Holding the vehicle stationary on
uphill gradients .............................. 143
Kickdown ....................................... 143
Manual drive program ....................144
Overview ........................................ 140
Problem (malfunction) ...................147
Program selector button ................143
Pulling away ................................... 136
Starting the engine ........................ 135
Steering wheel paddle shifters ...... 144
Transmission position display ........ 141
Transmission positions .................. 142
Automatic transmission
emergency mode ............................... 147B
Backup lamp Changing bulbs .............................. 109
Display message ............................ 211
Bag hook

............................................ 243
BAS (Brake Assist System) ................. 59
Battery (SmartKey) Checking .......................................... 70
Important safety notes .................... 70
Replacing ......................................... 70
Battery (vehicle)
Charging ........................................ 288
Display message ............................ 213
Important safety notes .................. 285
Jump starting ................................. 289
Belt force limiter
Activation ......................................... 49
Function ........................................... 49
Blinds
see Roller sunblind Blind Spot Assist
Activating/deactivating .................195
Display message

............................ 216
Notes/function .............................. 181
Brake Assist
see BAS (Brake Assist System)
Brake fluid
Display message ............................ 207
Notes ............................................. 332
Brake lamps
Adaptive ........................................... 62
Changing bulbs .............................. 109
Display message ............................ 209
Brakes
ABS .................................................. 59
Adaptive Brake Assist ......................61
BAS .................................................. 59
Brake fluid (notes) .........................332
Display message ............................ 201
Driving tips .................................... 154
Important safety notes .................. 154
Maintenance .................................. 155
Parking brake ................................ 150
Warning lamp ................................. 225
Breakdown
see Flat tire
see Towing away/tow-starting
Bulbs
see Changing bulbs C
Calling up a malfunction see Display messages


Car
see Vehicle
Care
Carpets .......................................... 277
Car wash ........................................ 271
Display ........................................... 275
Exhaust pipe .................................. 275
Exterior lights ................................ 274
Gear or selector lever ....................276
Interior ........................................... 275
Matte finish ................................... 273
Notes ............................................. 271
Paint .............................................. 273
Plastic trim .................................... 276 Index
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ProCarManuals.com

Switching the rear window
defroster on/off
............................ 128
Switching the ZONE function on/
off
.................................................. 126
Cockpit
Overview .......................................... 28
see Instrument cluster
COLLISION PREVENTION ASSIST
Display message ............................ 201
Operation/notes .............................. 60
COMAND
see separate operating instructions
Combination switch ..........................100
Compass Calibrating ..................................... 264
Calling up ....................................... 263
Setting ........................................... 263
Consumption statistics (on-board
computer) .......................................... 189
Convenience closing feature ..............78
Convenience opening feature ............78
Coolant (engine) Checking the level ......................... 269
Display message ............................ 212
Filling capacity ............................... 333
Important safety notes .................. 333
Temperature gauge ........................ 186
Warning lamp ................................. 231
Cooling
see Climate control
Cornering light function
Changing bulbs .............................. 108
Display message ............................ 209
Function/notes ............................. 101
Crash-responsive emergency
lighting ............................................... 104
Cruise control Activation conditions .....................158
Cruise control lever .......................158
Deactivating ................................... 159
Display message ............................ 218
Driving system ............................... 157
Function/notes ............................. 158
Important safety notes .................. 157
Setting a speed .............................. 159
Storing and maintaining current
speed ............................................. 158Cup holder
Center console .............................. 248
Important safety notes ..................247
Rear compartment
.........................248
Customer Assistance Center (CAC) ...24
Customer Relations Department .......24 D
Dashboard see Instrument cluster


Dashboard lighting
see Instrument cluster lighting
Data
see Technical data
Daytime running lamps
Display message ............................ 211
Switching on/off (on-board
computer) ...................................... 197
Switching on/off (switch) ................ 99
Dealerships
see Qualified specialist workshop
Declarations of conformity ................. 23
Delayed switch-off Exterior lighting (on-board
computer) ...................................... 198
Interior lighting .............................. 198
Diagnostics connection ......................24
Digital speedometer .........................190
DIRECT SELECT lever see Automatic transmission
Display (cleaning instructions) ........275
Display messages ASSYST PLUS ................................ 270
Calling up (on-board computer) ..... 200
Driving systems ............................. 215
Engine ............................................ 212
General notes ................................ 200
Hiding (on-board computer) ........... 200
Lights ............................................. 208
Safety systems .............................. 201
SmartKey ....................................... 223
Tires ............................................... 219
Vehicle ........................................... 220
Distance display (on-board
computer) .......................................... 194 Index
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E
EASY-VARIO-PLUS system Cargo compartment enlargement ..240
EBD (electronic brake force
distribution)
Display message ............................ 203
Function/notes ................................
64
ECO display
Function/notes ............................. 153
On-board computer ....................... 190
ECO start/stop function
Automatic engine start .................. 137
Automatic engine switch-off .......... 137
Deactivating/activating ................. 138
General information ....................... 136
Important safety notes .................. 136
Electronic Stability Program
see ESP ®
(Electronic Stability Program)
Emergency release
Driver's door .................................... 75
Vehicle ............................................. 75
Emergency spare wheel
General notes ................................ 325
Important safety notes .................. 325
Removing ....................................... 326
Technical data ............................... 326
Emergency Tensioning Devices
Activation ......................................... 39
Function ........................................... 49
Safety guidelines ............................. 40
Emergency unlocking
Tailgate ............................................ 76
Emissions control
Service and warranty information .... 21
Engine
Check Engine warning lamp ........... 231
Display message ............................ 212
ECO start/stop function ................ 136
Engine number ............................... 329
Irregular running ............................ 139
Jump-starting ................................. 289
Starting problems .......................... 139
Starting the engine with the
SmartKey ....................................... 135
Switching off .................................. 150
Tow-starting (vehicle) ..................... 294 Engine electronics
Problem (malfunction) ...................139
Engine oil
Adding ........................................... 268
Additives ........................................ 332
Checking the oil level ..................... 267
Checking the oil level using the
dipstick
.......................................... 268
Display message ............................ 214
Filling capacity ............................... 332
Notes about oil grades ................... 332
Notes on oil level/consumption .... 267
Viscosity ........................................ 332
ESP ®
(Electronic Stability
Program) Deactivating/activating ................. 194
Deactivating/activating (notes) ....... 63
Display message ............................ 201
ETS .................................................. 62
Function/notes ......................... 62, 63
Important safety information ........... 62
Warning lamp ................................. 227
ETS (Electronic Traction System) ....... 62
Exhaust check ................................... 152
Exhaust pipe (cleaning instructions) 275
Exterior lighting Setting options ................................ 98
see Lights
Exterior mirrors
Adjusting ......................................... 92
Dipping (automatic) .........................93
Folding in/out (automatically) ......... 93
Folding in/out (electrically) ............. 93
Folding in when locking (on-board
computer) ...................................... 199
Out of position (troubleshooting) .....93
Setting ............................................. 93
Storing settings (memory function) .. 95
Storing the parking position ............. 94
Eyeglasses compartment ................. 237 F
Filler cap see Fuel filler flap


First-aid kit ......................................... 280
Flat tire MOExtended tires .......................... 281 Index
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ProCarManuals.com

(vehicles without the EASY-
VARIO-PLUS system)
.....................240
Folding the backrest (rear
compartment) forwards/back
(vehicles with the EASY-VARIO-
PLUS system) ................................ 241
Seat belts
Adjusting the height ......................... 48
Belt force limiters ............................ 49
center rear-compartment seat
.........48
Cleaning ......................................... 277
Correct usage .................................. 46
Emergency Tensioning Devices ........ 49
Fastening ......................................... 47
Important safety guidelines .............45
Releasing ......................................... 48
Safety guidelines ............................. 40
Warning lamp ................................. 224
Warning lamp (function) ................... 49
Seats
Adjusting (electrically) .....................88
Adjusting (manually) ........................ 88
Adjusting the 4-way lumbar
support ............................................ 90
Adjusting the head restraint ............ 89
Cleaning the cover ......................... 276
Correct driver's seat position ........... 86
Important safety notes .................... 87
Seat heating problem ...................... 91
Storing settings (memory function) .. 95
Switching seat heating on/off ......... 91
Sensors (cleaning instructions) .......275
Service menu (on-board computer) . 196
Service products Brake fluid ..................................... 332
Coolant (engine) ............................ 333
Engine oil ....................................... 332
Fuel ................................................ 330
Important safety notes .................. 329
Refrigerant (air-conditioning
system) .......................................... 334
Washer fluid ................................... 334
Service work
see ASSYST PLUS
Settings
Factory (on-board computer) ......... 199
On-board computer ....................... 196
Setting the air distribution ...............126Setting the airflow
............................ 126
Side impact air bag ............................. 44
Side marker lamp (display
message) ............................................ 211
Side windows Cleaning ......................................... 274
Convenience closing feature ............ 78
Convenience opening feature
..........78
Important safety information ........... 77
Opening/closing .............................. 77
Problem (malfunction) .....................79
Resetting ......................................... 79
Sliding sunroof
see Panorama roof with power
tilt/sliding panel
SmartKey
Changing the battery ....................... 70
Changing the programming ............. 69
Checking the battery ....................... 70
Convenience closing feature ............ 78
Convenience opening feature .......... 78
Display message ............................ 223
Door central locking/unlocking ....... 68
Important safety notes .................... 68
Loss ................................................. 72
Mechanical key ................................ 69
Positions (ignition lock) ................. 135
Problem (malfunction) .....................72
Starting the engine ........................ 135
SmartKey positions (ignition lock) ..135
Snow chains ...................................... 301
Sockets Center console .............................. 251
Luggage compartment ................... 251
Points to observe before use ......... 250
Rear compartment ......................... 251
Specialist workshop ............................ 24
Speed, controlling see Cruise control
Speedometer
Activating/deactivating the
additional speedometer .................196
Digital ............................................ 190
In the Instrument cluster ................. 29
Segments ...................................... 187
Selecting the unit of measurement 196
see Instrument cluster Index
15
ProCarManuals.com

Wear indicator (definition)
.............318
Wheel rim (definition) ....................316
see Flat tire

Top Tether ............................................ 55
Towing Important safety guidelines ...........291
Installing the towing eye ................ 292
Removing the towing eye ...............292
Towing away
With both axles on the ground ....... 293
With front axle raised ..................... 293
Tow-starting
Emergency engine starting ............ 294
Important safety notes .................. 291
Installing the towing eye ................ 292
Removing the towing eye ...............292
Traction control ................................... 62
Transmission see Automatic transmission
Transmission position display .........141
Transporting the vehicle .................. 293
Trim pieces (cleaning instructions) . 276
Trip computer (on-board computer) 189
Trip odometer Calling up ....................................... 189
Resetting (on-board computer) ...... 190
Trunk
see Tailgate
Turn signals
Changing bulbs (front) ................... 108
Changing bulbs (rear) .................... 109
Display message ............................ 209
Switching on/off ........................... 100
Type identification plate
see Vehicle identification plate U
Unlocking Emergency unlocking .......................75
From inside the vehicle (central
unlocking button) ............................. 74 V
Vanity mirror (in the sun visor) ........ 249
Vehicle Correct use ...................................... 24
Data acquisition ............................... 25
Equipment
....................................... 21
Individual settings ..........................196
Limited Warranty ............................. 25
Loading .......................................... 306
Locking (in an emergency) ............... 75
Locking (SmartKey) .......................... 68
Lowering ........................................ 322
Maintenance .................................... 22
Parking for a long period ................ 152
Pulling away ................................... 136
Raising ........................................... 320
Reporting problems .........................24
Securing from rolling away ............320
Towing away .................................. 291
Tow-starting ................................... 291
Transporting .................................. 293
Unlocking (in an emergency) ........... 75
Unlocking (SmartKey) ......................68
Vehicle data ................................... 335
Vehicle data ....................................... 335
Vehicle dimensions ...........................335
Vehicle emergency locking ................75
Vehicle identification number see VIN
Vehicle identification plate ..............328
Vehicle tool kit .................................. 280
Video (DVD) ........................................ 193
VIN ...................................................... 328 W
Warning and indicator lamps ABS ................................................ 225
Brakes

........................................... 225
Check Engine ................................. 231
Coolant .......................................... 231
Distance warning ........................... 233
DISTRONIC PLUS ........................... 233
ESP ®
.............................................. 227
ESP ®
OFF ....................................... 228
Fuel tank ........................................ 231
Overview .......................................... 3018
Index
ProCarManuals.com

Warning and indicator lamps
Function Page
:
L Low-beam
headlamps
99
;
T Parking lamps
100
=
K High-beam
headlamps
100
?
÷ ESP
® 227
A
! Electric parking brake
(red)
230
B
!
Electric parking brake
(yellow) 230
C
· Distance warning
233
D
#! Turn signals
100 Function Page
E
6 SRS
230
F
ü Seat belt
224
G
? Coolant
231
H
R Rear fog lamp
100
I
N Front fog lamps
99
J
; Check Engine
231
K
æ Reserve fuel
231
L
å ESP
®
OFF 227
M
! ABS
225
N
J Brakes
22530
Instrument clusterAt a glance
ProCarManuals.com

R
Emergency Tensioning Device
for the front
seat belts and the outer seat belts in the
rear
R Seat belt force limiters for the front seat
belts and the outer seat belts in the rear
SRS reduces the risk of occupants coming
into contact with parts of the vehicle's interior
in the event of an accident. It can also reduce
the effect of the forces to which occupants
are subjected during an accident.
SRS warning lamp G
WARNING
The SRS self-check has detected a
malfunction if the 6 SRS indicator lamp:
R does not light up at all
R does not go out after approximately four
seconds after the engine is started
R lights up
after

the engine is started or while
the vehicle is in motion
For your safety, Mercedes-Benz strongly
recommends that you have the system
checked as soon as possible at a qualified
specialist workshop. SRS may otherwise fail
to activate when it is needed in the event of
an accident, which could lead to serious or
fatal injuries. SRS might also be activated
unexpectedly and unnecessarily, which could
also result in injury.
In addition, work carried out improperly on
SRS may render SRS inoperative or cause
unintended air bag deployment. Work on the
SRS system should only be carried out by
qualified specialist personnel. Consult a
qualified specialist workshop.
If it is necessary to modify an air bag system
to accommodate a person with disabilities,
contact an authorized Mercedes-Benz Center
for details. USA only: for further information,
contact our Customer Assistance Center at
1-800-FOR-MERCedes (1-800-367-6372).
The 6 SRS warning lamp in the instrument
cluster lights up when the ignition is switched on. It goes out no later than a few seconds
after the engine is started.
SRS
functions are

checked regularly when the
ignition is switched on or the engine is
running. Therefore, malfunctions can be
detected in good time.
Triggering of Emergency Tensioning
Device and air bags During the first stage of a collision, the air bag
control unit evaluates important physical
data relating to vehicle deceleration or
acceleration, such as:
R
duration
R direction
R magnitude
Based on the evaluation of this data, the air
bag control unit pre-emptively triggers the
Emergency Tensioning Device in the first
stage.
If there is an even higher rate of vehicle
deceleration or acceleration in a longitudinal
direction, the front

air bags are also deployed.
Your vehicle has adaptive, two-stage front air
bags. The air bag control unit evaluates
vehicle deceleration or acceleration in the
event of a collision. In the first deployment
stage, the front air bag is filled with enough
propellant gas to reduce the risk of injuries.
The front air bag is fully deployed if a second
deployment threshold is reached within a few
milliseconds.
The Emergency Tensioning Device and air bag
triggering thresholds are variable and are
adapted to the detected rate of deceleration
or acceleration of the vehicle. This process is
pre-emptive in nature. The triggering process
must take place in good time at the start of
the collision.
The rate of vehicle deceleration or
acceleration and the direction of the force are
essentially determined by:
R the distribution of forces during the
collision
R the collision angle Occupant safety
39
Safety Z
ProCarManuals.com

R
ADAPTIVE BRAKE ( Y
page 64)
(Y page 64)
R STEER CONTROL ( Y page 64)Important safety notes
If you fail to adapt your driving style or
become distracted, the driving safety
systems can neither reduce the risk of
accident nor override the laws of physics.
Driving safety systems are merely aids
designed to assist driving. You are
responsible for the distance to the vehicle in
front, for vehicle speed and for braking in
good time. Always

adapt your driving style to
suit the prevailing road, weather and traffic
conditions and maintain a safe distance from
the vehicle in front. Drive carefully.
i The driving safety systems described only
work as effectively as possible when there
is adequate contact between the tires and
the road surface. Pay particular attention
to the information regarding tires,
recommended minimum tire tread depths
etc. in the "Wheels and tires" section
(Y page 298).
In wintry driving conditions, always use
winter tires (M+S tires) and if necessary,
snow chains. Only in this way will the
driving safety systems described in this
section work as effectively as possible. ABS (Anti-lock Braking System)
Important safety notes i
Observe the "Important safety notes"
section for driving safety systems
(Y page 59). G
WARNING
If ABS is faulty, the wheels could lock when
braking. The steerability and braking
characteristics may be severely impaired.
Additionally, further driving safety systems are deactivated. There is an increased danger
of skidding and accidents.
Drive on carefully. Have ABS checked
immediately at a qualified specialist
workshop.
When ABS is malfunctioning, other systems,
including driving safety systems, will also
become inoperative. Observe

the information
on the ABS warning lamp ( Y page 225) and
display messages which may be shown in the
instrument cluster (Y page 201).
ABS regulates brake pressure in such a way
that the wheels do not lock when you brake.
This allows you to continue steering the
vehicle when braking.
ABS works from a speed of about 5 mph
(8 km/h) upwards, regardless of road-surface
conditions. ABS works on slippery roads,
even if you only brake gently.
The ! ABS warning lamp in the instrument
cluster lights up when the ignition is switched
on. It goes out when the engine is running.
Braking X
If ABS intervenes: continue to
depress the
brake pedal vigorously until the braking
situation 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, and
functions as a reminder to take extra care
while driving. BAS (Brake Assist System)
i Observe the "Important safety notes"
section ( Y page 59). Driving safety systems
59
Safety Z
ProCarManuals.com

Up to vehicle speeds of around 155 mph
(250 km/h
),
adaptive Brake Assist is capable
of reacting to moving objects that have
already been recognized as such at least once
over the period of observation. Adaptive
Brake Assist does not react to stationary
obstacles.
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.
In particular, the detection of obstacles can
be impaired if there is:
R dirt on the sensors or anything else
covering the sensors
R snow or heavy rain
R interference by other radar sources
R there are strong radar reflections, for
example in parking garages
R a narrow vehicle traveling in front, e.g. a
motorbike
R a vehicle traveling in front on a different line
relative to the center of your vehicle
Following damage to the front end of the
vehicle, have the configuration and operation
of the radar sensor checked at a qualified
specialist workshop. This also applies to
collisions at low speeds where there is no
visible damage to the front of the vehicle. Adaptive brake lights
If you brake sharply from a speed of more
than 50 km/h

or if braking is assisted by BAS
or Adaptive Brake Assist, the brake lamps
flash rapidly. In this way, traffic traveling
behind you is warned in an even more
noticeable manner.
If you brake sharply to a standstill from a
speed of more than 70 km/h, the hazard
warning lamps are activated automatically. If
the brakes are applied again, the brake lamps
light up continuously. 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 101).
i
Adaptive brake lamps

are only available in
certain countries. ESP
®
(Electronic Stability Program)
General notes i
Observe the "Important safety notes"
section ( Y page 59).
ESP ®
monitors driving stability and traction,
i.e. power transmission

between the tires 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 stabilize the
vehicle. The engine output is also modified to
keep the vehicle on the desired course within
physical limits. ESP ®
assists the driver when
pulling away on wet or slippery roads. ESP ®
can also stabilize the vehicle during braking.
ETS (Electronic Traction System) i
Observe the "Important safety notes"
section for driving safety systems
(Y page 59).
ETS traction control is part of ESP ®
.
ETS brakes the drive wheels individually 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.
ETS remains active when you deactivate
ESP ®
.
Important safety notes G
WARNING
If ESP ®
is malfunctioning, ESP ®
is unable to
stabilize the vehicle. Additionally, further
driving safety systems are deactivated. This
increases the risk

of skidding and an accident.
Drive on carefully. Have ESP ®
checked at a
qualified specialist workshop. 62
Driving safety systems
Safety
ProCarManuals.com

Characteristics when ESP
®
is deactivated
If ESP ®
is deactivated and one or more wheels
start to spin, the ÷ ESP®
warning lamp in
the instrument cluster flashes. In such
situations, ESP ®
will not stabilize the vehicle.
If you deactivate ESP ®
:
R ESP ®
no longer improves driving stability.
R the engine's torque is no longer limited and
the drive wheels are able to spin. The
spinning of the wheels results in a cutting
action, which provides better grip.
R ETS is still active.
R ESP ®
still provides support when you
brake. EBD (electronic brake force
distribution)
i Observe the "Important safety notes"
section for driving safety systems
(Y page 59). G
WARNING
If EBD has malfunctioned, the rear wheels can
still lock, e.g. under full braking. This
increases the risk

of skidding and an accident.
You should therefore adapt your driving style
to the different handling characteristics. Have
the brake system checked at a qualified
specialist workshop.
Observe information regarding indicator and
warning lamps ( Y page 225) as well as
display messages ( Y page 203).
EBD monitors and controls the brake
pressure on the rear wheels to improve
driving stability while braking. ADAPTIVE BRAKE
ADAPTIVE BRAKE enhances braking safety
and offers increased braking comfort. In
addition to the braking function, ADAPTIVE
BRAKE also has the HOLD function
(Y page 168) and hill start assist (Y page 136). For further information, see
Driving tips (Y page 154).
STEER CONTROL
STEER CONTROL helps

you by transmitting a
noticeable steering force to the steering
wheel in the direction required for vehicle
stabilization.
This steering assistance is provided in
particular if:
R both right wheels or both left wheels are on
a wet or slippery road surface when you
brake
R the vehicle starts to skid
If ESP ®
is malfunctioning, you will not receive
steering support from STEER CONTROL.
Power steering will, however, continue to
function. Theft deterrent locking system
Immobilizer
The immobilizer prevents your vehicle from
being started without the correct SmartKey.
X To activate: remove the SmartKey from
the ignition lock.
X To deactivate: switch on the ignition.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. The
engine can be started by anyone with a valid
SmartKey that is left inside the vehicle.
i The immobilizer is always deactivated
when you start the engine.
In the event that the engine cannot be
started when the starter battery is fully
charged, the immobilizer may be faulty.
Contact an authorized Mercedes-Benz
Center or call

1-800-FOR-MERCedes (in the
USA) or 1-800-387-0100 (in Canada). 64
Theft deterrent locking system
Safety
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