2012 MERCEDES-BENZ B-CLASS coolant temperature

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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Temperature
Coolant .......................................... 186
Outside temperature ...................... 187 Setting (climate control)
................125
Theft deterrent systems
ATA (Anti-Theft Alarm system) .........65
Immobilizer ...................................... 64
Through-loading ................................ 239
Time see separate operating instructions
TIREFIT kit .......................................... 282
Tire pressure Checking manually ........................305
Display message ............................ 219
Maximum ....................................... 304
Notes ............................................. 303
Not reached (TIREFIT) .................... 284
Reached (TIREFIT) .......................... 284
Recommended ............................... 301
Tire pressure loss warning
system
Important safety notes .................. 305
Restarting ...................................... 305
Tires
Aspect ratio (definition) ................. 318
Average weight of the vehicle
occupants (definition) .................... 316
Bar (definition) ............................... 316
Changing a wheel .......................... 319
Characteristics .............................. 316
Checking ........................................ 299
Definition of terms ......................... 316
Direction of rotation ......................319
Display message ............................ 219
Distribution of the vehicle
occupants (definition) .................... 318
DOT, Tire Identification Number
(TIN) ............................................... 315
DOT (Department of
Transportation) (definition) ............ 316
GAWR (Gross Axle Weight Rating)
(definition) ..................................... 317
GVW (Gross Vehicle Weight)
(definition) ..................................... 317
GVWR (Gross Vehicle Weight
Rating) (definition) .........................317
Important safety notes .................. 298Increased vehicle weight due to
optional equipment (definition)
......316
Kilopascal (kPa) (definition)
...........317
Labeling (overview) ........................ 312
Load bearing index (definition) ...... 318
Load index ..................................... 315
Load index (definition) ...................317
M+S tires ....................................... 300
Maximum loaded vehicle weight
(definition) ..................................... 317
Maximum load on a tire (definition) 317
Maximum permissible tire
pressure (definition) ....................... 317
Maximum tire load ......................... 310
Maximum tire load (definition) .......317
MOExtended tires .......................... 300
Optional equipment weight
(definition) ..................................... 318
PSI (pounds per square inch)
(definition) ..................................... 317
Replacing ....................................... 319
Service life ..................................... 300
Sidewall (definition) .......................318
Speed rating (definition) ................ 317
Storing ........................................... 319
Structure and characteristics
(definition) ..................................... 316
Summer tires ......................... 157, 300
Temperature .................................. 312
TIN (Tire Identification Number)
(definition) ..................................... 318
Tire bead (definition) ......................318
Tire pressure (definition) ................ 318
Tire pressures (recommended) ...... 316
Tire size (data) ............................... 323
Tire size designation, load-bearing
capacity, speed rating .................... 313
Tire tread ....................................... 299
Tire tread (definition) .....................318
Total load limit (definition) ............. 318
Traction ......................................... 311
Traction (definition) ....................... 318
Tread wear ..................................... 311
Uniform Tire Quality Grading
Standards ...................................... 311
Uniform Tire Quality Grading
Standards (definition) .................... 316
Unladen weight (definition) ............ 317 Index
17
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Instrument cluster
Displays and controls
Function Page
:
Speedometer with
segments
187
;
Multifunction display 188
=
Tachometer
187 Function Page
?
Coolant temperature 186
A
Fuel gauge
B
Instrument cluster lighting 186Instrument cluster
29At a glance
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Problem Possible causes/consequences and
M SolutionsThe engine is not
running smoothly and
is misfiring. There is a malfunction in the engine electronics or in a mechanical
component of the engine management system.
X
Only depress the accelerator pedal slightly.
X Have the cause rectified immediately at a qualified specialist
workshop.
Otherwise, non-combusted fuel may get into the catalytic
converter and damage it. The coolant
temperature display is
showing more than
248 ‡
(120 †). The
coolant warning lamp
may also be lit and a
warning tone may
sound. The coolant level is too low. The coolant is too hot and the engine
is no longer being cooled sufficiently.
X
Stop as soon as possible and allow the engine and the coolant
to cool down.
X Check the coolant level (Y page 269). Observe the warning
notes as you do so and add coolant if necessary. Automatic transmission
Important safety notes
G
WARNING
If the engine speed is above the idling speed
and you engage transmission position D or
R, the vehicle
could pull away suddenly. There
is a risk of an accident.
When engaging transmission position D or R,
always firmly depress the brake pedal and do
not simultaneously accelerate. G
WARNING
The automatic transmission switches to
neutral position N when you switch off the
engine. The vehicle may roll away. There is a
risk of an accident.
After switching off the engine, always switch
to parking position P. Prevent the parked
vehicle from rolling away by applying the
parking brake. DIRECT SELECT lever
Overview of transmission positions The DIRECT SELECT lever is on the right of the
steering column.
j
Park position with parking lock
k Reverse gear
i Neutral
h Drive
i The DIRECT SELECT lever always returns
to its original position. The current
transmission position
P, R

, N or D appears
in the transmission position display
(Y page 141) in the multifunction display. 140
Automatic transmission
Driving and parking
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Useful information
i This Operator's Manual describes all
models and all standard and optional
equipment of your vehicle available at the
time of publication of the Operator's
Manual. Country-specific differences are
possible. Please note
that your vehicle may
not be equipped with all features
described. This also applies to safety-
related systems and functions.
i Read the information on qualified
specialist workshops: ( Y page 24).Important safety notes
G
WARNING
If you operate information systems and
communication equipment integrated in the
vehicle while driving, you will be distracted
from traffic conditions. You could also lose
control of the vehicle. There is a risk of an
accident.
Only operate the equipment when the traffic
situation permits. If

you are not sure that this
is possible, park the vehicle paying attention
to traffic conditions and operate the
equipment when the vehicle is stationary. G
WARNING
If the instrument cluster has failed or
malfunctioned, you may not recognize
function restrictions in systems relevant to
safety. The operating safety of your vehicle
may be impaired. There is a risk of an
accident.
Drive on carefully. Have the vehicle checked
at a qualified specialist workshop
immediately.
You must observe the legal requirements for
the country in

which you are currently driving
when operating the on-board computer.
The on-board computer only shows messages
or warnings from certain systems in the multifunction display. You should therefore
make sure your vehicle is operating safely at
all times. Otherwise, a vehicle that is not
operating safely may cause an accident.
For an overview, see the instrument panel
illustration (
Y page 29). Displays and operation
Instrument cluster lighting
The lighting in the instrument cluster, in the
displays and the controls in the vehicle
interior can be

adjusted using the brightness
control knob.
The brightness control knob is located on the
bottom left of the instrument cluster
(Y page 29).
X Turn the brightness control knob clockwise
or counter-clockwise.
If the light switch is set to Ã, T or
L, the brightness is dependent upon
the brightness of the ambient light.
i The light sensor

in the instrument cluster
automatically controls the brightness of
the multifunction display.
In daylight, the displays in the instrument
cluster are not illuminated. Coolant temperature display
G
WARNING
Driving when your engine is overheated can
cause some fluids

which may have leaked into
the engine compartment to catch fire. You
could be seriously burned.
Steam from an overheated engine can cause
serious burns which can occur just by opening
the engine hood. Stay away from the engine
if you see or hear steam coming from it.
Stop the vehicle in a safe location away from
other traffic. Turn off the engine, get out of the
vehicle and do not stand near the vehicle until
the engine has cooled down. 186
Displays and operation
On-board computer and displays
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!
A display message
is shown if the coolant
temperature is too high.
If the coolant temperature is over
248 ‡(120 †), do not continue driving. The
engine will otherwise be damaged.
The coolant temperature gage is in the
instrument cluster on the right-hand side.
Under normal operating conditions and with
the specified coolant level, the coolant
temperature may rise to 248 ‡ (120 †). Tachometer
! Do not drive in the overrevving range, as
this could damage the engine.
The red band

in the tachometer indicates the
engine's overrevving range.
The fuel supply is interrupted to protect the
engine when the red band is reached. Outside temperature display
You should pay special attention to road
conditions when temperatures are around
freezing point.
The outside temperature display is in the
multifunction display.
Changes in the outside temperature are
displayed after a short delay. Speedometer with segments
The segments in the speedometer indicate
which speed range is available.
R Cruise control activated ( Y page 157):
The segments light up from the stored
speed to the maximum speed.
R DISTRONIC PLUS activated (Y page 159):
One or two segments in the set speed
range light up.
R DISTRONIC PLUS detects

a vehicle in front:The segments between the speed of the
vehicle in front and the stored speed light
up. Operating the on-board computer
Overview :
Multifunction display
; Switches on the Voice Control System;
see the separate operating instructions
= Right control panel
? Left control panel
A Back button
X To activate the on-board computer: turn
the SmartKey to position 1 in the ignition
lock.
You

can control the multifunction display and
the settings in the on-board computer using
the buttons on the multifunction steering
wheel. Displays and operation
187
On-board computer and displays Z
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Display messages Possible causes/consequences and
M Solutionsb
Switch Off Lights The lights are still switched on when you leave the vehicle. A
warning tone also sounds.
X
Turn the light switch to Ã. Adaptive Highbeam
Assist Inoperative Adaptive Highbeam Assist is faulty.
X
Visit a qualified specialist workshop. Adaptive Highbeam
Assist Currently
Unavailable See
Operator's Manual Adaptive Highbeam Assist is deactivated and temporarily
inoperative. Possible causes are:
R
the windshield in the camera's field of vision is dirty.
R visibility is impaired due to heavy rain, snow or fog.
X Clean the windshield.
If the system detects that the camera is fully operational again,
the Adaptive Highbeam Assist Now Available message is
displayed.
Adaptive Highbeam Assist is operational again. Engine
Display messages Possible causes/consequences and
M Solutions+
Check Coolant
Level See
Operator's Manual The coolant level is too low.
!
Avoid making long
journeys with too little coolant in the engine
cooling system. The engine will otherwise be damaged.
X Add coolant, observing the warning notes before doing so
(Y page 269).
X If coolant needs to be added more often than usual, have the
engine coolant system checked at a qualified specialist
workshop. ? The fan motor is faulty.
X
At coolant temperatures below 248 ‡ (120 †), drive to the
nearest qualified specialist workshop.
X Avoid subjecting the engine to heavy loads, e.g. driving in
mountainous terrain, and stop-and-go traffic.212
Display messages
On-board computer and displays
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Display messages Possible causes/consequences and
M Solutions?
Coolant Too Hot
Stop Vehicle Turn
Engine Off The coolant is too hot.
A warning tone also sounds.
G WARNING
Do not drive when your engine is overheated. This can cause some
fluids which may have leaked into the engine compartment to
catch fire.
Steam from the overheated engine can also cause serious burns
which can occur just by opening the hood.
There is a risk of injury.
X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Secure the vehicle against rolling away ( Y page 149).
X Wait until the engine has cooled down.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.
X Do not start the engine again until the display message goes out
and the coolant temperature is below 248 ‡ (120 †).
Otherwise, the engine could be damaged.
X Pay attention to the coolant temperature display.
X If the temperature increases again, visit a qualified specialist
workshop immediately.
Under
normal operating conditions and with the specified coolant
level, the coolant temperature may rise to 248 ‡ (120 †). # The battery is not being charged.
A warning tone also sounds.
Possible causes are:
R
a defective alternator
R a torn poly-V-belt
R a malfunction in the electronics
X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Open the hood.
X Check whether the poly-V-belt is torn.
If the poly-V-belt is torn:
! Do not continue

driving. The engine could otherwise overheat.
X Consult a qualified specialist workshop.
If the poly-V-belt is not damaged:
X Visit a qualified specialist workshop immediately. Display messages
213
On-board computer and displays Z
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