2015 MERCEDES-BENZ B-CLASS SPORTS engine overheat

GWARNING
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.
GWARNING
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.
!Do not warm up the engine with the vehi-
cle stationary. Drive off immediately. Avoid high engine speeds and driving at full throt-
tle until the engine has reached its operat-
ing temperature.
Only shift the automatic transmission to
the desired drive position when the vehicle is stationary.
Where possible, avoid spinning the drive
wheels when pulling away on slippery
roads. You could otherwise damage the
drive train.
SmartKey positions
SmartKey
gTo remove the SmartKey
(shift the transmission to position P)
1Power supply for some consumers, such
as the windshield wipers
2Ignition (power supply for all consumers)
and drive position
3To start the engine
iThe SmartKey can be turned in the igni-
tion lock even if it is not the correct Smart- Key for the vehicle. The ignition is not
switched on. The engine cannot be started.
Start/Stop button
General notes
Vehicles with KEYLESS-GO are equipped with
SmartKeys featuring the integrated KEYLESS-
GO function and a detachable Start/Stop but-
ton.
A check which periodically establishes a radio connection between the vehicle and the
SmartKey determines whether a valid Smart-Key is in the vehicle. This occurs, for example,
when starting the engine.
When you insert the Start/Stop button into
the ignition lock, the system needs approx-
imately two seconds recognition time. You
can then use the Start/Stop button.
Pressing the Start/Stop button several times
in succession corresponds to the different
key positions in the ignition lock. This is only
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ANeutral
Do not shift the transmission toN
while driving. Otherwise, the auto-
matic transmission could be dam-
aged.
No power is transmitted from the
engine to the drive wheels.
Releasing the brakes will allow you
to move the vehicle freely, e.g. to
push it or tow it.
If ESP ®
is deactivated or faulty:
shift the transmission to position N
if the vehicle is in danger of skid-
ding, e.g. on icy roads.
If you switch the engine off with the transmission in position Ror D, the
automatic transmission shifts to N
automatically.
!Rolling in neutral Ncan damage
the drive train.
7Drive
The automatic transmission
changes gear automatically. All
forward gears are available.
Driving tips
Changing gear
The automatic transmission shifts to the indi- vidual gears automatically when it is in trans-
mission position D. This automatic gear shift-
ing behavior is determined by:
R the selected drive program ( Ypage 147)
R the position of the accelerator pedal (Y page 146)
R the road speed
Accelerator pedal position
Your style of driving influences how the auto-
matic transmission shifts gear:
R little throttle: early upshifts
R more throttle: late upshifts
Holding the vehicle stationary on uphill
gradients
GWARNING
If the clutch overheats, the electronic man-
agement system is automatically deactivated. This interrupts the power transmission. The
vehicle may, for example, roll backwards on
gradients. There is a risk of an accident.
Never hold the vehicle stationary on uphill
gradients by depressing the accelerator.
The clutch may overheat if you hold the vehi- cle stationary on uphill gradients by depress- ing the accelerator pedal. If the clutch over-
heats, a warning tone sounds.
The
Stop Vehicle Shift to P Leave
EngineRunningdisplay message appears in
the multifunction display. You will only be
able to continue your journey once the clutch
has cooled down and the display message in
the multifunction display has disappeared.
Never hold the vehicle stationary on uphill
gradients by depressing the accelerator.
Instead, only ever hold the vehicle stationary
on uphill gradients by:
R depressing the brake pedal
R activating the HOLD function
R engaging the electric parking brake
Kickdown
Use kickdown for maximum acceleration.
X Depress the accelerator pedal beyond the
pressure point.
The automatic transmission shifts to a
lower gear depending on the engine speed.
X Ease off the accelerator pedal once the
desired speed is reached.
The automatic transmission shifts back up.
For further information on kickdown in man-
ual drive program M(Y page 148).
146Automatic transmission
Driving an d parking

Apart from driving style, consumption is
dependent on many factors such as, e.g.: Rload
R tire pressure
R cold start
R choice of route
R electrical consumers switched on
These factors are not included in the ECO dis-
play.
The evaluation of your driving style is carried
out using the following three categories:
R
Acceleration(evaluation of all accelera-
tion processes):
- The bar fills up: moderate acceleration,
especially at higher speeds
- The bar empties: sporty acceleration
R
Constant(assessment of driving behavior
at all times)
- The bar fills up: constant speed and
avoidance of unnecessary acceleration
and deceleration
- The bar empties: fluctuations in speed
R
Coasting(assessment of all deceleration
processes) - The bar fills up: anticipatory driving,
keeping your distance and early release
of the accelerator. The vehicle can coast
without use of the brakes.
- The bar empties: frequent braking
An economical driving style specially requires
driving at moderate engine speeds.
To achieve a higher value in the categories
AccelerationandConstant:
R observe the gearshift recommendations.
R drive in drive program E.
On long journeys at a constant speed, e.g. on
the highway, only the bar for
Constantwill
change.
The ECO display summarizes the driving char- acteristics from the start of the journey to its completion. For this reason, the bars change
dynamically at the beginning of the journey.
On longer journeys, there are fewer changes. For more dynamic changes, carry out a man-
ual reset.
For further information on the ECO display,
see ( Ypage 196).
Braking
Important safety notes
GWARNING
If you shift down on a slippery road surface in an attempt to increase the engine's braking
effect, the drive wheels could lose their grip.
There is an increased danger of skidding and
accidents.
Do not shift down for additional engine brak-
ing on a slippery road surface.
Downhill gradients
!On long and steep gradients, you must
reduce the load on the brakes by shifting to
a lower gear in good time. This allows you to
take advantage of the engine's braking
effect. For this, you need to have selected
manual drive program M. This helps you to
avoid overheating the brakes and wearing
them out excessively.
When you take advantage of the engine's
braking effect, a drive wheel may not turn
for some time, e.g. on a slippery road sur-
face. This could cause damage to the drive train. This type of damage is not covered bythe Mercedes-Benz warranty.
Briefly depressing the accelerator pedal on
downhill gradients while the manual drive
program Mis temporarily activated: the auto-
matic transmission may switch to the last
active automatic drive program Eor S. The
automatic transmission may shift to a higher
gear. This can reduce the engine's braking
effect.
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Heavy and light loads
GWARNING
If you rest your foot on the brake pedal while
driving, the braking system can overheat. Thisincreases the stopping distance and can even
cause the braking system to fail. There is a
risk of an accident.
Never use the brake pedal as a footrest. Never
depress the brake pedal and the accelerator
pedal at the same time.
!Depressing the brake pedal constantly
results in excessive and premature wear to
the brake pads.
If the brakes have been subjected to a heavy load, do not stop the vehicle immediately.
Drive on for a short while. This allows the air-
flow to cool the brakes more quickly.
Wet roads
If you have driven for a long time in heavy rain
without braking, there may be a delayed reac- tion from the brakes when braking for the firsttime. This may also occur after the vehicle has
been washed or driven through deep water.
You have to depress the brake pedal more
firmly. Maintain a greater distance from the
vehicle in front.
After driving on a wet road or having the vehi-
cle washed, brake firmly while paying atten-
tion to the traffic conditions. This will warm up
the brake discs, thereby drying them more
quickly and protecting them against corro-sion.
Limited braking performance on salt-
treated roads
If you drive on salted roads, a layer of salt
residue may form on the brake discs and
brake pads. This can result in a significantly
longer braking distance. R
In order to prevent any salt build-up, apply
the brakes occasionally while paying atten-
tion to the traffic conditions.
R Carefully depress the brake pedal and the
beginning and end of a journey.
R Maintain a greater distance to the vehicle
ahead.
Servicing the brakes
!If the red brake warning lamp lights up in
the instrument cluster and you hear a warn- ing tone while the engine is running, the
brake fluid level may be too low. Observe
additional warning messages in the multi-
function display.
The brake fluid level may be too low due tobrake pad wear or leaking brake lines.
Have the brake system checked immedi-
ately. This work should be carried out at a
qualified specialist workshop.
!A function or performance test should
only be carried out on a 2-axle dynamom-
eter. If you are planning to have the vehicle tested on such a dynamometer, contact an
authorized Mercedes-Benz Center to
obtain further information first. Otherwise,
you could damage the drive train or the
brake system.
!As the ESP ®
system operates automati-
cally, the engine and the ignition must be
switched off (the SmartKey must be in posi-
tion 0or 1in the ignition lock) if:
R the electric parking brake is tested on a
brake dynamometer (for a maximum of
ten seconds)
R the vehicle is towed with the front axle
raised.
Braking triggered automatically by ESP ®
may seriously damage the brake system.
All checks and maintenance work on the
brake system must be carried out at a quali-
fied specialist workshop. Consult a qualified
specialist workshop to arrange this.
158Driving tips
Driving and parking

You should pay special attention to road con-
ditions when temperatures are around freez-
ing point.
For more information on driving with snow
chains, see ( Ypage 305).
For more information on driving with summer tires, see ( Ypage 304).
Observe the notes in the "Winter operation"
section ( Ypage 304).
Driving systems
Cruise control
General notes
Cruise control maintains a constant road
speed for you. It brakes automatically in order
to avoid exceeding the set speed. On long and
steep downhill gradients, especially if the
vehicle is laden, you must select a low gear in good time. For this, you will need to have
selected manual drive program M
( Y page 148). By doing so, you will make use
of the braking effect of the engine. This
relieves the load on the brake system and
prevents the brakes from overheating and
wearing too quickly.
Use cruise control only if road and traffic con- ditions make it appropriate to maintain a
steady speed for a prolonged period. You canstore any road speed above 20 mph
(30 km/h).
The speed indicated in the speedometer may differ slightly from the speed stored.
Important safety notes
If you fail to adapt your driving style, cruise
control can neither reduce the risk of an acci- dent nor override the laws of physics. Cruise
control cannot take into account the road,
traffic and weather conditions. Cruise control
is only an aid. You are responsible for the dis-
tance to the vehicle in front, for vehicle speed, for braking in good time and for staying in
your lane. Do not use cruise control: R
in road and traffic conditions which do not
allow you to maintain a constant speed e.g.
in heavy traffic or on winding roads
R on slippery road surfaces. Braking or accel-
erating could cause the drive wheels to lose
traction and the vehicle could then skid
R when there is poor visibility, e.g. due to fog,
heavy rain or snow
If there is a change of drivers, advise the new
driver of the speed stored.
Cruise control lever
:To activate or increase speed
;To activate or reduce speed
=Deactivating cruise control
?To activate at the current speed/last
stored speed
When you activate cruise control, the stored
speed is shown in the multifunction display
for five seconds.
Activation conditions
To activate cruise control, all of the following activation conditions must be fulfilled:
R the electric parking brake must be released.
R ESP ®
must be active, but not intervening.
R the transmission must be in position D.
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trol Offtrol Offmessage in the multifunction dis-
play for approximately five seconds.
iWhen you switch off the engine, the last
speed stored is cleared.
DISTRONIC PLUS
General notes
DISTRONIC PLUS regulates the speed and
automatically helps you maintain the dis-
tance to the vehicle detected in front. Vehi-
cles are detected with the aid of the radar
sensor system. DISTRONIC PLUS brakes
automatically to avoid exceeding the set
speed or to maintain the designated distance
from the vehicle in front.
Change into a lower gear in good time on long
and steep downhill gradients. This is espe-
cially important if the vehicle is laden. By
doing so, you will make use of the braking
effect of the engine. This relieves the load on
the brake system and prevents the brakes
from overheating and wearing too quickly.
If DISTRONIC PLUS detects that there is a risk of a collision, you will be warned visually and
acoustically. DISTRONIC PLUS cannot pre-
vent a collision without your intervention. An
intermittent warning tone will then sound and the distance warning lamp will light up in theinstrument cluster. Brake immediately in
order to increase the distance to the vehicle
in front or take evasive action provided it is
safe to do so.
DISTRONIC PLUS operates in range between0 mph (0 km/h) and 120 mph (200 km/h).
Do not use DISTRONIC PLUS while driving on
roads with steep gradients.
Important safety notes
GWARNING
DISTRONIC PLUS does not react to:
R people or animals
R stationary obstacles on the road, e.g. stop-
ped or parked vehicles
R oncoming and crossing traffic
As a result, DISTRONIC PLUS may neither give
warnings nor intervene in such situations.
There is a risk of an accident.
Always pay careful attention to the traffic sit- uation and be ready to brake.
GWARNING
DISTRONIC PLUS cannot always clearly iden-tify other road users and complex traffic sit- uations.
In such cases, DISTRONIC PLUS may:
R give an unnecessary warning and then
brake the vehicle
R neither give a warning nor intervene
R accelerate or brake unexpectedly
There is a risk of an accident.
Continue to drive carefully and be ready to
brake, in particular when warned to do so by
DISTRONIC PLUS.
GWARNING
DISTRONIC PLUS brakes your vehicle with up to 50% of the maximum possible deceleration.
If this braking force is insufficient, DISTRONIC
PLUS warns you visually and audibly. There is a risk of an accident.
In such cases, apply the brakes yourself and
try to take evasive action.
!If DISTRONIC PLUS or the HOLD function
is activated, the vehicle brakes automati-
cally in certain situations.
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Useful information
iThis Operator's Manual describes all
models and all standard and optional equip- ment 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.
iRead the information on qualified special-
ist workshops ( Ypage 24).
Important safety notes
GWARNING
If you operate information systems and com-
munication equipment integrated in the vehi-
cle while driving, you will be distracted from
traffic conditions. You could also lose controlof 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 equip-
ment when the vehicle is stationary.
You must observe the legal requirements for
the country in which you are currently driving when operating the on-board computer.
GWARNING
If the instrument cluster has failed or mal-
functioned, 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 immedi-ately.
The on-board computer only shows messages
or warnings from certain systems in the mul- tifunction display. You should therefore make sure your vehicle is operating safely at all
times.
If the operating safety of your vehicle is
impaired, pull over as soon as it is safe to do
so. Contact a qualified specialist workshop.
For an overview, see the instrument panel
illustration (
Ypage 29).
Displays and operation
Instrument cluster lighting
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.
The lighting in the instrument cluster, in the
displays and the controls in the vehicle inte-
rior can be adjusted using the brightness con- trol 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.
Coolant temperature display
GWARNING
Opening the hood when the engine is over-
heated or when there is a fire in the engine
compartment could expose you to hot gases
or other service products. There is a risk of
injury.
Let an overheated engine cool down before
opening the hood. If there is a fire in the
engine compartment, keep the hood closed
and contact the fire department.
!A display message is shown if the coolant
temperature is too high.
192Displays and operation
On-board computer and displays

Display messagesPossible causes/consequences andMSolutions
?
Coolant Too Hot
Stop Vehicle Turn
Engine Off
The coolant is too hot.
A warning tone also sounds.
GWARNING
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 ( Ypage 152).
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 †). Other-
wise, 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 †).
#
SeeOperator'sManZ
ual
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
!Do not continue driving. The engine could otherwise overheat.
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 ( Ypage 152).
X Consult a qualified specialist workshop.
Display messages223
On-board computer and displays
Z