park assist MERCEDES-BENZ B-CLASS HATCHBACK 2011 Service Manual

Display messages Possible causes/consequences and
M Solutions
Vehicles with Becker
®
MAP PILOT: if the Becker ®
MAP PILOT is
no tc onnected, the radar sensor system is deactivated automati-
cally.
Blind Spot Assist is not available.
X Connect the Becker ®
MAP PILOT; see the separate operating
instructions. Lane Keeping
Assist currently
unavailable See
Owner's Manual Lane Keeping Assist is deactivated and temporarily inoperative.
Possible causes:
R
the windscreen is dirty in the camera's field of vision.
R visibility is impaired due to heavy rain, snow or fog.
R there are no lane markings for a longer period.
R the lane markings are worn, dark or covered, e.g. by dirt or snow.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Engage the electric parking brake.
X Clean the windscreen.
If the system detects that the camera is fully operational, the dis-
play message disappears.
Lane Keeping Assist or Active Lane Keeping Assist is operational
again. Lane Keeping
Assist inoperative Lane Keeping Assist is faulty.
X
Visit a qualified specialist workshop. Display messages
223On-board computer and displays Z

Display messages Possible causes/consequences and
M Solutions
Blind Spot Assist
currently unavail‐
able See Owner's
Manual Blind Spot Assis
tis temporarily inoperative. Possible causes:
R you have established the electrical connection between the
trailer and your vehicle.
R the sensors are dirty.
R function is impaired due to heavy rain or snow.
R the radar sensor system is outside the operating temperature
range.
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio sta-
tions or other sources of electromagnetic radiation.
The yellow 9indicator lamps also light up in the exterior mir-
rors.
X When towing a trailer, confirm the display message with a.
If you are driving without a trailer and the displaym essage does
not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Engage the electric parking brake.
X Clean the sensors (Y page 270).
X Restart the engine.
If the system detects that the sensors are fully operational, the
display message disappears.
Blind Spot Assist is operational again. Blind Spot Assist
inoperative Blind Spot Assist is faulty.
The yellow
9indicator lamps also light up in the exterior mir-
rors.
X Visit a qualified specialist workshop. Park Assist
cancelled The driver's door is open and the driver's seat belt has not been
fastened.
X
Repeat the parking process with the seat belt fastened and the
driver's door closed. You have inadvertently touched the multifunction steering wheel
while steering intervention was active.
X
While steering intervention is active, make sure that the multi-
function steering wheel is not touched. The vehicle has started to skid and ESP
®
has intervened.
X Use Active Parking Assist again later (Y page 166).224
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
M Solutions
Park Assist
inoperative You have just carried out a large number of turning or parking
manoeuvres.
Active Parking Assis
twill become available again after approx-
imately ten minutes (Y page 166).
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Switch off and restart the engine.
If the display message continues to be displayed:
X Visit a qualified specialist workshop. PARKTRONIC is faulty.
X
Visit a qualified specialist workshop. DISTRONIC PLUS
off DISTRONIC PLUS has been deactivated (Y
page 154). If it was
deactivated automatically, a warning tone also sounds. DISTRONIC PLUS
available again DISTRONIC PLUS is operational again after having been tempo-
rarily unavailable. You can now reactivate DISTRONIC PLUS
(Y
page 154). Display messages
225On-board computer and displays Z

Display messages Possible causes/consequences and
M Solutions
DISTRONIC PLUS
currently unavail‐
able See Owner's
Manual DISTRONIC is deactivated and temporarily inoperative. Possible
causes:
R
the DISTRONIC PLUS cover in the radiator grille is dirty.
R function is impaired due to heavy rain or snow.
R the sensors in the bumpers are dirty.
R the rada rsensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio sta-
tions or other sources of electromagnetic radiation.
R the system is outside the operating temperature range.
R the on-board voltage is too low.
Aw arning tone also sounds.
If the display message does no tdisappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Engage the electric parking brake.
X Clean the DISTRONIC PLUS cover in the radiator grille
(Y page 270).
X Clean the bumpers (Y page 270).
X Restar tthe engine.
If the system detects that the sensors are fully operational, the
display message disappears.
DISTRONIC is operational again. DISTRONIC PLUS
inoperative DISTRONIC PLUS is faulty. BAS PLUS (Brake Assist PLUS) may
also have failed.
Aw
arning tone also sounds.
X Visi taqualified specialist workshop. DISTRONIC PLUS
inactive You have depressed the accelerator pedal. DISTRONIC PLUS is no
longer controlling the speed of the vehicle.
X
Remove your foot from the accelerator pedal. DISTRONIC PLUS
--- km/h An activation condition for DISTRONIC PLUS is not fulfilled.
X
Check the activation conditions for DISTRONIC PLUS
(Y page 156). DISTRONIC PLUS and
SPEEDTRONIC
inoperative DISTRONIC PLUS and SPEEDTRONIC are faulty. A warning tone
also sounds.
X
Visit a qualified specialist workshop. 226
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
M Solutions
A The tailgate is open.
G WARNING
Whe nthe engine is running, exhaust gases can enter the vehicle
interior if the tailgate is open.
There is a risk of poisoning.
X Close the tailgate. ? The bonnet is open.
G WARNING
The open bonnet may block your view when the vehicle is in
motion.
There is a risk of accident.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Engage the electric parking brake.
X Close the bonnet. C At least one door is open.
Awarning tone also sounds.
X Close all doors. j
Check trailer
hitch lock The trailer tow hitch is no
tcorrectly engaged.
Aw arning tone also sounds.
X Stop the vehicle immediately, paying attentio ntoroad and traf-
fic conditions, and switch off the engine.
X Engage the electric parking brake.
X Allow the trailer tow hitch ball coupling to engage in the end
position (Y page 183).
Otherwise, the trailer may detach itself. D
Power
steering mal‐
function See Own‐
er's Manual The power steering assistance is faulty. You will need to use more
force to steer.
Aw
arning tone also sounds.
X Chec kwhether you are able to apply the extra force required.
X If you are able to steer safely: carefully drive on to a qualified
specialist workshop.
X If you are unable to steer safely: do not drive on. Contact the
nearest qualified specialist workshop. 230
Display messagesOn-board computer and displays

Safety systems
Problem Possible causes/consequences and
M Solutions
J
The red brake system
warning lamp comes on
while the engine is run-
ning. A warning tone
also sounds. There is insufficient brake fluid in the brake fluid reservoir.
G WARNING
The braking effect may be impaired.
There is a risk of accident.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.
X Engage the electric parking brake.
X Do not top up the brake fluid. Topping up will not remedy the
fault.
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction
display. !
The yellow ABS warning
lamp is lit while the
engine is running. ABS (Anti-lock Brake System) has been deactivated due to a fault.
For this reason, BAS (Brake Assist), BAS PLUS, ESP ®
(Electronic
Stability Program), PRE-SAFE ®
, the HOLD function, hill start assist,
the adaptive brake lights and ESP ®
trailer stabilisation are also
deactivated, for example.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
This limits the steerability of the vehicle when braking and may
increase the braking distance.
If ESP ®
is deactivated or not operational, the vehicle's stability
during standard driving manoeuvres is reduced.
There is a risk of accident.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop.
If the ABS control unit is faulty, there is also a possibility that other
systems, such as the navigation system or the automatic trans-
mission, will not be available. Warning and indicator lamps in the instrument cluster
233On-board computer and displays Z

Flat tyre
Preparing the vehicle
Your vehicle may be equipped with:
R MOExtended tyres (tyres with run-flat char-
acteristics) (Y page 276)
R a TIREFIT kit
R an emergency spare wheel (only for certain
countries)
You can find information on changing/fitting
wheels in the "Wheel change" section
(Y page 298).
i Vehicle preparation is no tnecessary on
vehicles with MOExtended tyres.
i Vehicles with MOExtended tyres are not
equipped with a TIREFIT kit at the factory.
It is therefore recommended that you addi-
tionally equip your vehicle with a TIREFIT kit
if you fit tyres that do not feature run-flat
characteristics, e.g. winter tyres. A TIREFIT
kit can be obtained from a qualified spe-
cialist workshop.
X Stop the vehicle as far away as possible
from traffic on solid, non-slippery and level
ground.
X Switch on the hazard warning lamps.
X Apply the electric parkin gbrake manually
(Y page 145).
X Bring the front wheels into the straight-
ahead position.
X Vehicles with manual transmission:
engage first or reverse gear.
X Vehicles with automatic transmission:
move the DIRECT SELECT lever to P.
X Switch off the engine.
X Remove the key from the ignition lock.
X All occupants must get out of the vehicle.
Make sure that they are not endangered as
they do so.
X Make sure that no one is near the danger
area whilst a wheel is being changed .Any-
one who is not directly assisting in the wheel change should, for example, stand
behind the barrier.
X Ge tout of the vehicle. Pay attention to traf-
fic conditions when doing so.
X Close the driver's door.
X Place the warning triangle ( Ypage 274) a
suitable distance away. Observe legal
requirements. MOExtended tyres (tyres with run-flat
characteristics)
G
WARNING
When driving in emergency mode, the driving
characteristics deteriorate, e.g. when corner-
ing, accelerating quickly and when braking.
There is a ris kofaccident.
Do not exceed the state dmaximum speed.
Avoid abrupt steering and driving manoeu-
vres, and driving ove robstacles (kerbs, pot-
holes, off-road). This applies in particular to a
laden vehicle.
Stop driving in emergency mode if:
R you hear banging noises.
R the vehicle starts to shake.
R you see smoke and smell rubber.
R ESP ®
is intervening constantly.
R there are tears in the sidewalls of the tyre.
After driving in emergency mode, have the
wheel rims checked at a qualified specialist
workshop with regard to their further use. The
faulty tyre must be replaced.
With MOExtended tyres (tyres with run-flat
characteristics), you can continue to drive
your vehicle even if there is a total loss of
pressure in one or more tyres.
MOExtended tyres may only be used in con-
junction with an activated tyre pressure loss
warning system.
The driving distance possible is 80 km when
the vehicle is partially laden, and 30 km when
the vehicle is fully laden. 276
Flat tyreBreakdown assistance

X
To reduce the tyre pressure: depress
pressure release button :next to pres-
sure gauge ;. X
To remove the tyre sealant bottle from the
tyre inflation compressor ,press together
the locking tabs on the yellow cap.
X Pull the tyre sealant bottle out of the tyre
inflation compressor.
The filler hose stays on the tyre sealant
bottle.
X Stow the tyre sealant bottle, the tyre infla-
tion compresso rand the warning triangle.
X Drive to the neares tspecialist qualified
workshop and have the tyre changed there.
X Have the tyre sealant bottle and the filler
hose replaced as soon as possible at a
qualified specialist workshop.
X Have the tyre sealant bottle replaced every
four years at a qualified specialist work-
shop. H
Environmental note
Have the used tyre sealant bottle disposed of
professionally, e.g. at aqualified specialist
workshop. Battery
Important safety notes
Special tools and exper tknowledge are
required when working on the battery, e.g.
removal and fitting. Yo ushould therefore
have all work involving the battery carried out
at a qualified specialist workshop. G
WARNING
Work carried out incorrectly on the battery
can, for example, lead to a short circuit and
damage your vehicle's electronic system. This
can disrupt driving safety systems such as
ABS (anti-lock braking system) or ESP ®
(Elec-
tronic Stability Program).
R If ABS malfunctions, the wheels can lock
during braking. This limits the steerability
of the vehicle when braking and the braking
distance may increase. There is a risk of
accident.
R If ESP ®
malfunctions, the vehicle will not be
stabilised if it starts to skid or a wheel starts
to spin. There is a risk of accident.
You should therefore have all work involving
the battery carried out at a qualified specialist
workshop. G
WARNING
Comply with safety precautions and take pro-
tective measures when handling batteries. Risk of explosion
Fire, naked flames and
smoking are prohibited
when handling the battery.
Avoid creating sparks.280
BatteryBreakdown assistance

Battery acid is caustic.
Avoid contact with the skin,
eyes or clothing.
Wea
rsuitable protective
clothing, in particular
gloves, an apro nand a face
mask.
Immediately rinse acid
splashes off with clean
water. Consult a doctor if
necessary. Wear eye protection.
Keep children away.
Observe this Owner's Man-
ual.
G
WARNING
For safety reasons, Mercedes-Benz recom-
mends tha tyou only use batteries which have
been tested and approved for your vehicle by
Mercedes-Benz. These batteries provide
increased impact protection to prevent vehi-
cle occupants from suffering acid burns
should the battery be damaged in the event
of an accident.
To prevent acid burns, observe the following
safety notes when handling batteries:
R do not lean over the battery.
R do not place any metal objects on a battery.
Otherwise, you could cause a short circuit
and the battery's gas mixture could ignite.
R make sure that you do not create an elec-
trostatic charge, e.g. by wearing synthetic
clothing or as a result of friction on fabrics.
Therefore, you should not pull or slide the
battery over carpets or other synthetic
materials. R
never touch the battery first. To discharge
a possible electrostatic charge, step out of
the vehicle first and touch the bodywork.
R do not wipe the battery using a cloth. The
battery may explode as a result of electro-
static charge or due to flying sparks. H
Environmental note Batteries contain pollutants.
It is illegal to dispose of them
with the household rubbish.
They must be collected sep-
arately and disposed of in an
environmentally responsible
recycling system.
Dispose of batteries in an
environmentally responsible
manner
.Take discharged
batteries to a qualified spe-
cialis tworkshop or to a col-
lection point for used batter-
ies.
! Have the battery checked regularly at a
qualified specialist workshop.
Observe the service intervals in the Service
Booklet or contact a qualified specialist
workshop for more information.
! You should have all work involving the
battery carried out at aqualified specialist
workshop. In the exceptional case that it is
necessary for you to disconnect the battery
yourself, make sure that:
R you switch off the engine and remove the
key. On vehicles with KEYLESS-GO,
ensure that the ignition is switched off.
Chec kthat all the indicator lamps in the
instrument cluster are off. Otherwise,
electronic components, such as the
alternator, may be damaged.
R you first remove the negative terminal
clamp and then the positive terminal
clamp. Never swap the terminal clamps. Battery
281Breakdown assistance Z

Otherwise, the vehicle's electronic sys-
tem may be damaged.
R in vehicles with automatic transmission,
the transmission is locked in position P
after disconnecting the battery. The vehi-
cle is secured against rolling away. You
can then no longer move the vehicle.
The battery and the cover of the positive
terminal clamp must be fitted securely dur-
ing operation.
In order for the battery to achieve the maxi-
mum possible service life, it must always be
sufficiently charged.
Like other batteries, the vehicle battery may
discharge over time if you do not use the
vehicle. In such cases, have the battery dis-
connected at a qualified specialist workshop.
You can also charge the battery with a
charger recommended by Mercedes-Benz.
For more information, please contact a quali-
fied specialist workshop.
Have the battery charge checked more fre-
quently if you use the vehicle mainly for short
trips or if you leave it standing idle for a
lengthy period. Consult a qualified specialist
workshop if you wish to leave your vehicle
parked up for a long period of time.
i When you park the vehicle, remove the
key if you do not require any electrical con-
sumers. The vehicle will then use very little
energy, thus conserving battery power.
i If the power supply has been interrupted,
e.g. if the battery was discharged, you must
carry out the following tasks:
R set the clock (audio system/COMAND
Online, see the separate operating
instructions).
R reset the function for automatically fold-
ing the exterior mirrors in/out by folding
the mirrors out once (Y page 92). Charging the battery
G
WARNING
Only charge the battery in a well-ventilated
area. As the battery is being charged, gases
can escape and generate minor explosions.
This could injure you and other persons or
cause damage to the paintwork or acid cor-
rosion on the vehicle.
You can obtain information on battery charg-
ers which allow the battery to be charged
while still installed from a qualified specialist
workshop. G
WARNING
There is a risk of acid burns during the charg-
ing process due to the gases which escape
from the battery. Do not lean over the battery
during the charging process. G
WARNING
Battery acid is caustic. Avoid contact with the
skin, eyes or clothing.
! Only charge the installed battery with a
battery charger which has been tested and
approved by Mercedes-Benz.T hese battery
chargers allow the battery to be charged
while still installed in the vehicle.
! Only use battery chargers with a maxi-
mum charging voltage of 14.8 V.
! Only charge the battery using the jump-
start connection point.
The jump-starting connection point is in the
engine compartment (Y page 283).
Read the battery charger's operating instruc-
tions before charging the battery.
X Open the bonnet (Y page 262).
X Connect the battery charger to the positive
terminal and earth point in the same order
as when connecting the donor battery in
the jump-starting procedure
(Y page 283). 282
BatteryBreakdown assistance