2011 MERCEDES-BENZ B-CLASS HATCHBACK ECU

Problem Possible causes/consequences and
M Solutions
Vehicles with a petrol
engine:
The engine is not run-
ning 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.
Otherwise, non-combusted fuel may get into the catalytic con-
verter and damage it.
X Have the cause rectified immediately at a qualified specialist
workshop. The coolant tempera-
ture display is showing
more than 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 265). Observe the warning
notes as you do so and top up the coolant if necessary. If the coolant level is correct, the engine radiator fan may be faulty.
The coolant is too hot and the engine is no longer being cooled
sufficiently.
X If the coolant temperature is less than 120 †, you can continue
driving to the nearest qualified specialist workshop.
X Avoid heavy loads on the engine as you do so, e.g. driving on
mountain roads and stop-start traffic. Manual transmission
Important safety notes
G
WARNING
The movement of the pedals must not be
impaired in any way. Do not keep any objects
in the driver's footwell. Make sure that floor-
mats or carpets are correctly secured and
that there is sufficient clearance for the ped-
als.
Do not place several floormats on top of one
another. G
WARNING
Do not change down for additional engine
braking on a slippery road surface. This could
cause the drive wheels to lose their grip and
the vehicle could skid. This could cause you to lose control of your vehicle and cause an
accident.
Gear lever
! Only engage gear when the clutch pedal
is depressed.
! When shifting between 5thand 6thgear,
you should always push the gear lever all
the way to the right. Otherwise, you could
shift unintentionally into 3rdor4th gear
and damage the transmission.
If you shift down at too high a speed (trans-
mission braking), this can cause the engine
to overrev, leading to engine damage.
Do not use the clutch bite point to keep the
vehicle stationary on uphill gradients.
There is otherwise a risk of damaging the
clutch. Manual transmission
133Driving and parking Z

!
On long and steep downhill gradients,
especially if the vehicle is ladenort owing
a trailer, you must shift into gear 1, 2or3
in good time. This uses the engine's braking
effect .This relieves the load on the brake
system and prevents the brakes from over-
heating and wearing too quickly. Gear lever
k
Reverse gear
1 to6
Forward gears Shifting to neutral N
X
Depress the clutch pedal fully.
X Move the gear lever to position N:. Neutral N with ECO start/stop func-
tion activated
In neutral N, the engine is switched off if the
vehicle speed is below a certain threshold and
the clutch pedal is not depressed.
For further information on the ECO start/stop
function, see (Y page 129). Engaging reverse gear
! Only shift into reverse gear Rwhen the
vehicle is stationary. Otherwise, you could
damage the transmission.
X Pull the gear lever up, push it to the left and
then pull it back.
i The ECO start/stop function is not avail-
able when reverse gear is engaged.
For further information on the ECO start/
stop function: (Y page 129). Shift recommendation
The gearshift recommendations assist you in
adopting an economical driving style. The rec-
ommended gear is shown in the multifunction
display. X
Shift gear according to gearshift recom-
mendation :shown in the multifunction
display of the instrumentc luster. Automatic transmission
Important safety notes
G
WARNING
The movemen tofthe pedals must not be
impaired in any way.D o not keep any objects
in the driver's footwell. Make sure that floor-
mats or carpets are correctly secured and
that there is sufficient clearance for the ped-
als. 134
Automatic transmissionDriving and parking

Problem Possible causes/consequences and
M Solutions
The fuel filler flap can-
not be opened. The fuel filler flap is not unlocked.
or
The key battery is discharged.
X
Unlock the vehicle (Y page 72).
or
X Unlock the vehicle using the emergency key element
(Y page 73). The fuel filler flap is unlocked, but the opening mechanism is jam-
med.
X
Consult a qualified specialist workshop. Parking
Important safety notes
G
WARNING
Only remove the key from the ignition lock
when the vehicle is stationary, as you cannot
steer the vehicle when the key is removed.
Never leave children unsupervised in the vehi-
cle. They might release the electric parking
brake. This could lead to aserious or fatal
accident. G
WARNING
Under no circumstances should the exhaust
system come into contact with flammable
materials such as dry grass or petrol, for
example. Do not park the vehicle on dry grass-
land or harvested grain fields. The hot exhaust
system could otherwise ignite the flammable
material and set the vehicle on fire.
To ensure that the vehicle is secured against
rolling away unintentionally:
R the electric parking brake must be applied.
R on vehicles with manual transmission,
engage first gear or reverse gear.
R on vehicles with automatic transmission,
the transmission must be in position Pand
the transmission position display must
show Pin the multifunction display. R
the key must be removed from the ignition
lock.
R on uphill or downhill gradients, turn the
fron twheels towards the kerb. Switching off the engine
Important safety notes G
WARNING
If the engine is not running, there is no power
assistance for the steering and brakes. Steer-
ing and braking then requires significantly
greater effort.
As a result, you might lose control of the vehi-
cle, cause an accident and injure yourself and
others.
Therefore, do not switch off the engine while
you are driving.
Vehicles with manual transmission X
Shift to either first gear or reverse gear R.
X Turn the key to position 0in the ignition
lock and remove it.
The immobiliser is activated.
X Apply the electric parking brake. 144
ParkingDriving and parking

tance between your vehicl
eand the vehicle in
front becomes too small.
i Whe nchanging lanes, DISTRONIC PLUS
monitors the left lane for left-hand-drive
vehicles and the right lane for right-hand-
drive vehicles.
Stopping G
WARNING
Never get out of the vehicle when DISTRONIC
PLUS is activated.
DISTRONIC PLUS must also never be oper-
ated, activated or deactivated by a passenger
or from outside the vehicle.
DISTRONIC PLUS does not replace the elec-
tric parking brake and must not be used for
parking.
The DISTRONIC PLUS braking effect is can-
celled and the vehicle can start moving if:
R DISTRONIC PLUS is deactivated using the
cruise control lever.
R you accelerate.
R there is a malfunction in the system or an
interruption in the power supply, e.g. bat-
tery failure.
R the electrical system in the engine com-
partment, the battery or the fuses are tam-
pered with.
R the battery is disconnected.
If you wish to leave the vehicle or park it,
deactivate DISTRONIC PLUS and secure the
vehicle against rolling away.
If DISTRONIC PLUS detects that the vehicle
in front is stopping, it brakes your vehicle until
it is stationary.
Once your vehicle is stationary, it remains
stationary and you do not need to depress the
brake.
i After a time, the electric parking brake
secures the vehicle and relieves the service
brake.
i Depending on the specified minimum dis-
tance, your vehicle will come to a standstill at a sufficient distance behind the vehicle
in front.T
he specified minimum distance is
set using the control on the cruise control
lever.
The electric parking brake secures the vehicle
automatically if DISTRONIC PLUS is activated
and:
R the driver's door is open and the driver's
seat belt is unfastened.
R the engine is switched off, unless it is auto-
matically switched off by the ECO start/
stop function.
R a system fault occurs.
R the power supply is not sufficient.
If a fault occurs, then the transmission may
be shifted into position Pautomatically.
Storing the current speed or calling up the
last stored speed G
WARNING
Only call up a stored speed if you know what
that speed is and if it is suitable for the current
traffic and driving situation. You can other-
wise endanger yourself or others by uninten-
tionally triggering sudden acceleration or
braking.
X Briefly pull the cruise control lever
(Y page 155) towards you.
X Remove your foot from the accelerator
pedal.
DISTRONIC PLUS is activated. The first
time it is activated, the current speed is
stored. Otherwise, it sets the vehicle cruise
speed to the previously stored value. 158
Driving systemsDriving and parking

Deactivating DISTRONIC PLUS
There are several ways to deactivate DIS-
TRONIC PLUS:
X
Briefly press the cruise control lever for-
wards :.
or
X Brake, unless the vehicle is stationary.
or
X Briefly press the cruise control lever in the
direction of arrow =.
Variable SPEEDTRONIC is selected. LIM
indicator lamp ;in the cruise contro llever
lights up.
When you deactivate DISTRONIC PLUS, you
will see the DISTRONIC PLUS off message
in the multifunction display for approximately
five seconds.
i The last speed stored remains stored until
you switch off the engine.
DISTRONIC PLUS is automatically deactiva-
ted if:
R you engage the electric parking brake or if
the vehicle is automatically secured with
the electric parking brake.
R you are driving slower than 10 km/h and
there is no longer a vehicle in front, or if the
vehicle in fron tis no longer detected.
R ESP ®
intervenes or if you deactivate ESP ®
.
R the transmission is in the P,Ror Nposition.
R you pull the cruise control lever towards
you in order to pull away, and the front- passenger door or one of the rear doors is
open.
R the vehicle has skidded.
If DISTRONIC PLUS is deactivated, you will
hear a warning tone. You will see the DIS‐ TRONIC PLUS off message in the multifunc-
tion display for approximately five seconds.
In the Assistance menu (Y page 198) of the
on-board computer, you can select the dis-
tance display. Distance display when DISTRONIC PLUS is deacti-
vated
:
Vehicle in front, if detected
; Distance indicator: current distance to
the vehicle in front
= Specified minimum distance to the vehi-
cle in front; adjustable
? Own vehicle
X Select the Distance display function
using the on-board computer
(Y page 198).
Tips for driving with DISTRONIC PLUS General notes
The following contains descriptions of certain
road and traffic conditions in which you must
be particularly attentive. In such situations,
brake if necessary. DISTRONIC PLUS is then
deactivated.160
Driving systemsDriving and parking

Crossing vehicles
DISTRONIC PLUS may detect vehicles that
are crossing your lane by mistake. Activating
DISTRONIC PLUS at traffic lights with cross-
ing traffic, for example, could cause your vehi-
cle to pull away unintentionally. HOLD function
General notes The HOLD function can assis
tthe driver in the
following situations:
R when pulling away, especially on steep
slopes
R when manoeuvring on steep slopes
R when waiting in traffic
The vehicle is kept stationary without the
driver having to depress the brake pedal.
The braking effect is cancelled and the HOLD
function is deactivated when you depress the
accelerator pedal to pull away.
Important safety notes G
WARNING
The vehicle's brakes are applied when the
HOLD function is activated. For this reason,
deactivate the HOLD function if the vehicle is
to be set in motion by other means (e.g. in a
car wash or by towing). G
WARNING
Never get out of the vehicle when the HOLD
function is activated. The HOLD function must never be operated
or deactivated by a passenger or from outside
the vehicle.
The HOLD function does not replace the elec-
tric parking brake and must not be used for
parking.
The braking effect of the HOLD function is
cancelled and the vehicle could roll away if:
R the HOLD function is deactivated by
depressing the accelerator pedal or the
brake pedal.
R there is a malfunction in the system or an
interruption in the power supply, e.g. bat-
tery failure.
R the electrical system in the engine com-
partment, the battery or the fuses are tam-
pered with.
R the battery is disconnected.
If you leave the vehicle or park it, deactivate
the HOLD function and secure the vehicle
against rolling away.
Activation conditions You can activate the HOLD function if:
R
the vehicle is stationary.
R the engine is running or if it has been auto-
matically switched off by the ECO start/
stop function.
R the driver's door is closed or if your seat
belt is fastened.
R the electric parking brake is released.
R the transmission is in position D,Ror N.
R DISTRONIC PLUS is deactivated.
Activating the HOLD function X
Make sure that the activation conditions
are met.
X Depress the brake pedal.
X Quickly depress the brake pedal further
until ë appears in the multifunction dis-
play.
The HOLD function is activated. You can
release the brake pedal. 162
Driving systemsDriving and parking

i
If depressing the brake pedalt he first
time does not activate the HOLD function,
wait briefly and then try again.
Deactivating the HOLD function The HOLD function is deactivated automati-
cally if:
R you accelerate and the transmission is in
position Dor R.
R you shift the transmission to position P.
R you depress the brake pedal again with a
certain amount of pressure until ëdis-
appears from the multifunction display.
R you secure the vehicle using the electric
parking brake.
R you activate DISTRONIC PLUS.
i After a time, the electric parking brake
secures the vehicle and relieves the service
brake.
The electric parking brake secures the vehicle
automatically if the HOLD function is activa-
ted and:
R the driver's door is open and the driver's
seat belt is unfastened.
R the engine is switched off, unless it is auto-
matically switched off by the ECO start/
stop function.
R a system fault occurs.
R the power supply is not sufficient.
If a fault occurs, then the transmission may
be shifted into position Pautomatically. PARKTRONIC
Important safety notes G
WARNING
PARKTRONIC is only an aid and may not
detect all obstacles. It is not a substitute for
attentive driving.
You are always responsible for safety and
must continue to pay attention to your imme-
diate surroundings when parking and manoeuvring. You could otherwise endanger
yourself and others.
G
WARNING
Make sure that no persons or animals are in
the manoeuvring range. Otherwise, they
could be injured.
! When parking, pay particular attention to
objects above or below the sensors, such
as flower pots or trailer drawbars. PARK-
TRONIC does not detect such objects when
they are in the immediate vicinity of the
vehicle. You could damage the vehicle or
the objects.
The sensors may not detect snow and
objects which absorb ultrasonic sources.
Ultrasonic sources, such as an automatic
car wash, a lorry's compressed-air brakes
or a pneumatic drill, could cause PARK-
TRONIC to malfunction.
PARKTRONIC may not function correctly on
uneven terrain.
PARKTRONIC is an electronic parking aid with
ultrasonic sensors. It indicates visually and
audibly the distance between your vehicle
and an object.
PARKTRONIC is activated automatically if
you:
R switch on the ignition
R shift to position D,Ror Non vehicles with
automatic transmission
R release the electric parking brake
PARKTRONIC is deactivated at speeds above
18 km/h. It is reactivated at lower speeds.
PARKTRONIC monitors the area around your
vehicle using six sensors in the front bumper
and four sensors in the rear bumper. Driving systems
163Driving and parking Z

X
Secure the traile ragainst rolling away.
X Remove the trailer cable and decouple the
trailer. Folding in the ball coupling
G
WARNING
Make sure that no persons or animals are in
the pivoting range of the ball coupling. Other-
wise, they could be injured.
X Fold the ball coupling back in if you are not
using the trailer tow hitch.
X Place the protective covering on the ball
coupling.
The release wheel is located behind the left-
hand side trim panel in the boot. X
To open the cover: turn handle:anti-
clockwise and fold down cover ;and
remove it. X
Pull out release wheel =.
X Turn release wheel =anti-clockwise as far
as it will go.
The ball coupling disengages and folds out
behind the rear bumper. Indicator
lamp ?flashes. X
Press the ball coupling in the direction of
the arrow until it engages behind the
bumper.
Indicator lamp ?goes out and the mes-
sage in the multifunction display disap-
pears. Trailer power supply
! You can connect accessories with a
power rating of up to 240 W to the perma-
nent power supply and with a power rating
of up to 180 W to the power supply that is
switched on via the ignition lock.
The trailer battery may not be charged from
the power supply.
X To switch the connected power supply
on or off: turn the key in the ignition lock
to position 2or 0respectively.
When it leaves the factory, your vehicle's
trailer socket is equipped with a permanent
power supply and a power supply that is
switched on via the ignition lock.
The permanent power supply is supplied via
trailer socket pin 9.
The power supply that is switched on via the
ignition lock is supplied via trailer socket pin
10. Towing
atrailer
185Driving an d parking Z