2015 MERCEDES-BENZ B-CLASS HATCHBACK overheating

The braking performance of the electric motor
using recuperative braking is, in some operating modes, either reduced or not effective:
R when the charge status of the high-voltage
battery increases
R if the high-voltage battery is not yet at a nor-
mal operating temperature
R when driving close to the maximum speed
R when the vehicle is almost stationary
R in transmission position N
R during and after ESP stability control
If you do not make an additional effort to apply
the brake yourself, the braking effect may not be sufficient. If necessary, counteract the reduced regenerative braking effect by applying the
brake yourself.
Downhill gradients On long, steep gradients, you must reduce the
load on the brakes by selecting maximum recu- peration. This prevents the brakes overheating
and causing excessive wear.
Recuperation allows the vehicle to be deceler-
ated without placing a load on the braking sys-
tem.
Do not depress the brake pedal continuously
while the vehicle is in motion, e.g. never cause
the brakes to rub by constantly applying light
pressure to the pedal. This results in excessive
and premature wear to the brake pads.
Heavy and light loads G
WARNING
The braking system can overheat if you leave your foot on the brake pedal while driving.
This increases the braking distance and could
even cause the braking system to fail. There is
a risk of an accident.
Never use the brake pedal as a footrest. Do
not simultaneously depress both the brake
pedal and the accelerator pedal while driving.
! Depressing the brake pedal constantly
results in excessive and premature wear to
the brake pads.
If heavy demands are made on the brakes, do
not park the vehicle immediately. Drive on for a
short while. This allows the airflow to cool the
brakes more quickly. If the brakes have been used only moderately,
you should occasionally test their effectiveness.
To do this, brake more firmly from a higher
speed, paying attention to traffic conditions.
This improves the grip of the brakes.
Wet road surfaces 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 first
time. This may also occur after a car wash or
after driving through deep water.
You will have to depress the brake pedal more
firmly. Maintain a greater distance to the vehicle
in front.
After driving on a wet road or having the vehicle washed, brake firmly while paying attention to
the traffic conditions. This will warm up the
brake discs, thereby drying them more quickly
and protecting them against corrosion.
Limited braking performance on salt-
treated roads If you drive on salt-treated roads, a layer of salt
may form on the brake discs and pads. This can increase the braking distance considerably.
R In order to prevent any salt build-up, apply the
brakes occasionally while paying attention to the traffic conditions.
R Carefully depress the brake pedal at the end
of the journey and when starting the next
journey.
R Maintain a much greater distance to the vehi-
cle in front.
New brake pads/linings Brake pads/linings and discs that are either new
or have been replaced only achieve optimum
braking effect after several hundred kilometres
of driving. Compensate for the reduced braking effect by applying greater force to the brake
pedal.
For safety reasons, Mercedes-Benz recom-
mends that you only have brake pads/linings
fitted to your vehicle which have been approved
for Mercedes-Benz vehicles or which corre-
spond to an equivalent quality standard. Brake
pads/linings which have not been approved for
Mercedes-Benz vehicles or which are not of an
equivalent quality could affect your vehicle's
operating safety. Driving tips
149Driving and parking Z

Driving on wet roads
Aquaplaning If water has accumulated to a certain depth on
the road surface, there is a danger of aquaplan- ing occurring, even if:
R you are driving at low speeds
R the tyres have adequate tread depth
For this reason, drive in the following manner in the event of heavy rain or in conditions in which
aquaplaning can occur:
R lower your speed
R avoid tyre ruts
R avoid sudden steering movements
R brake carefully
Driving on flooded roads !
Bear in mind that vehicles travelling in front
or in the opposite direction create waves. This may cause the maximum permissible water
depth to be exceeded.
These notes must be observed under all cir-
cumstances. You could otherwise damage
the engine, the electronics or the transmis-
sion.
If you must drive on stretches of road on which
water has collected, please bear in mind that:
R in the case of standing water, the water level
must be no higher than the lower edge of the
vehicle body
R you should drive no faster than walking pace Winter driving
G
WARNING
If you increase the recuperation level on slip- pery road surfaces, the drive wheels may lose
their traction. This increases the risk of skid-
ding and having an accident.
Do not increase the recuperation level on slip-
pery road surfaces.
Have your vehicle winterproofed at a qualified
specialist workshop at the onset of winter.
You should drive particularly carefully on slip-
pery road surfaces. Avoid sudden acceleration, steering and braking manoeuvres. Do not use
cruise control.
If the vehicle threatens to skid or cannot be
stopped when moving at low speed:
X Shift the DIRECT SELECT lever to position N.
X Try to bring the vehicle under control by using
corrective steering.
The outside temperature indicator is not
designed to serve as an ice-warning device and
is therefore unsuitable for that purpose.
Changes in the outside temperature are dis-
played after a short delay.
Indicated temperatures just above the freezing
point do not guarantee that the road surface is
free of ice. The road may still be icy, especially in
wooded areas or on bridges.
You should pay special attention to road condi-
tions when temperatures are around freezing
point.
Further information on driving with snow chains (Y page 269).
Further information on driving with summer
tyres (Y page 268).
Observe the notes in the "Winter operation" sec-
tion (Y page 268). 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. Change into transmis-
sion position D-
(Y page 132) on long and steep
downhill gradients. This increases recuperation
in overrun mode. 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 are appropriate for maintaining a steady
speed for a prolonged period. You can store any road speed above 30 km/h.
The speed indicated in the speedometer may
differ slightly from the speed stored. 150
Driving syste
msDriving and parking

accelerates or brakes. If you do not know
what the stored speed is, the vehicle may
accelerate or brake unexpectedly. There is a
risk of an accident.
Take the traffic conditions into account
before calling up the stored speed. If you do
not know what the stored speed is, store the
desired speed again.
X Briefly pull the cruise control lever towards
you =.
X Remove your foot from the accelerator pedal.
The first time cruise control is activated, it
stores the current speed or regulates the
speed of the vehicle to the previously stored
speed.
Setting a speed Bear in mind that it may take a brief moment
until the vehicle has accelerated or braked to
the set speed.
X Press the cruise control lever up :for a
higher speed or down ?for a lower speed.
X Keep the cruise control lever pressed until the
desired speed is reached.
X Release the cruise control lever.
The new speed is stored.
X To adjust the set speed in 1 km/h incre-
ments: briefly press the cruise control lever
up : or down ?to the pressure point.
The last stored speed increases or decreases
in 1 km/h increments.
X To adjust the set speed in 10 km/h incre-
ments: briefly press the cruise control lever
up : or down ?beyond the pressure point.
The last stored speed increases or decreases
in 10 km/h increments.
i Cruise control is not deactivated if you
depress the accelerator pedal. For example, if
you accelerate briefly to overtake, cruise con-
trol adjusts the vehicle's speed to the last
speed stored after you have finished overtak-
ing. Deactivating cruise control There are several ways to deactivate cruise con-
trol:
X Briefly press the cruise control lever forwards
B.
or X Brake.
or X Briefly press the cruise control lever in the
direction of arrow A.
Variable SPEEDTRONIC is selected. LIM indi-
cator lamp ;in the cruise control lever lights
up.
Cruise control is automatically deactivated if:
R the vehicle is secured with the electric park-
ing brake
R you are driving at less than 30 km/h
R ESP ®
intervenes or you deactivate ESP ®
R you shift the transmission to position Nwhile
driving
If cruise control is deactivated, you will hear a
warning tone. You will see the Cruise con‐ Cruise con‐
trol off
trol off message in the multifunction display
for approximately five seconds.
i The last speed stored is cleared when you
switch off the engine. SPEEDTRONIC
General notes SPEEDTRONIC brakes automatically so that you
do not exceed the set speed. Change into trans-
mission position D-
(Y page 132) on long and
steep downhill gradients. This increases recu-
peration in overrun mode. This relieves the load on the brake system and prevents the brakes
from overheating and wearing too quickly. If youneed additional braking, depress the brake
pedal repeatedly rather than continuously.
i The speed indicated in the speedometer
may differ slightly from the limit speed stored.
Important safety notes If you fail to adapt your driving style, SPEED-
TRONIC can neither reduce the risk of an acci-
dent nor override the laws of physics. SPEED-
TRONIC cannot take into account road, weather152
Driving systemsDriving and parking

Other identifications, for example:
R 0 W-30
R 5 W-30
R 5 W-40
i Further information can be obtained from
any Mercedes-Benz Service Centre or on the
Internet at http://bevo.mercedes-benz.com. Brake fluid
G
WARNING
The brake fluid continuously absorbs mois-
ture from the air. This results in the boiling
point of the brake fluid lowering. If the boiling
point of the brake fluid is too low, vapour
pockets may form when the brakes are sub-
jected to a heavy load. This would impair brak- ing efficiency. There is a risk of an accident.
Have the brake fluid renewed at the prescri-
bed intervals.
When handling brake fluid, observe the impor-
tant safety notes on service products
(Y page 282).
The brake fluid change intervals can be found in the Service Booklet.
Only use brake fluid approved by Mercedes-
Benz according to MB-Freigabe or MB-Approval
331.0.
Information about approved brake fluid can be
obtained at any qualified specialist workshop or on the Internet at
http://bevo.mercedes-benz.com.
i Have the brake fluid regularly replaced at a
qualified specialist workshop and the replace- ment confirmed in the Service Booklet. Coolant
Important safety notes G
WARNING
If antifreeze comes into contact with hot com- ponents in the engine compartment, it may
ignite. There is a risk of fire and injury.
Let the engine cool down before you top up
the antifreeze. Make sure that antifreeze is not spilled next to the filler neck. Thoroughly
clean the antifreeze from components before
starting the engine.
! Only add coolant that has been premixed
with the desired antifreeze protection. You
could otherwise damage the engine.
Further information on coolants can be found in the Mercedes-Benz Specifications for Ser-
vice Products, MB Specifications for Service
Products 310.1, e.g. on the Internet at
http://bevo.mercedes-benz.com. Or contact
a qualified specialist workshop.
! Always use a suitable coolant mixture, even
in countries where high temperatures prevail.
Otherwise, the engine cooling system is not
sufficiently protected from corrosion and
overheating.
i Have the coolant regularly replaced at a
qualified specialist workshop and the replace- ment confirmed in the Service Booklet.
Comply with the important safety precautions
for service products when handling coolant
(Y page 282).
The coolant is a mixture of water and anti-
freeze/corrosion inhibitor. It is responsible for
the following:
R anti-corrosion protection
R antifreeze protection
R raising the boiling point
If antifreeze/corrosion inhibitor is present in the
correct concentration, the boiling point of the
coolant during operation will be approximately
130 †.
The antifreeze/corrosion inhibitor concentra-
tion in the engine cooling system should:
R be at least 50%. This will protect the engine
cooling system against freezing down to
approximately -37 †.
R not exceed 55% (antifreeze protection down
to -45 †). Heat will otherwise not be dissipa-
ted as effectively.
Mercedes-Benz recommends coolant or anti-
freeze/corrosion inhibitor concentrate in
accordance with
MB Specifications for Service Products 310.1.
i When the vehicle is first delivered, it is filled
with a coolant mixture that ensures adequate
antifreeze and corrosion protection. Service products and capacities
283Technical data Z