2012 MERCEDES-BENZ B-CLASS headlamp

Parking lamps/standing lamps
(halogen headlamps)
X
Switch off the lights.
X Open the hood.
X Turn housing cover : counter-clockwise
and pull it out.
X Pull out bulb holder ;.
X Take the bulb out of bulb holder ;.
X Insert the new bulb into bulb holder ;.
X Insert bulb holder ;.
X Align housing cover : and turn it
clockwise until it engages.
Turn signals (halogen headlamps) X
Switch off the lights.
X Open the hood.
X Turn bulb holder : counter-clockwise and
pull it out.
X Take the bulb out of bulb holder :
.X
Insert the new bulb into bulb holder :.
X Insert bulb holder : and turn it clockwise
until it engages.
Cornering light function (Intelligent
Light System) G
WARNING
These bulbs are pressurized.
They can explode when being changed if:
R they are still hot
R they hit an object when being removed
R they are dropped
There is a risk of injury.
You should wear eye protection and clean
gloves when you are changing a bulb. If
necessary, have bulbs changed at a qualified
specialist workshop. X
Switch off the lights.
X Open the hood.
X Turn housing cover : counter-clockwise
and pull it out.
X Turn bulb holder ; counter-clockwise and
pull it out.
X Take the bulb out of bulb holder ;

.
X Insert the new bulb into bulb holder ;.
X Insert bulb holder ;
into the
lamp and turn
it clockwise.
X Align housing cover : and turn it
clockwise until it engages.108
Replacing bulbs
Lights and windshield wipers
ProCarManuals.com

Activating/deactivating surround
lighting and exterior lighting delayed
switch-off
If you have activated the
Locator
Lighting: function
and
the light switch is set
to Ã, the following functions are activated
when it is dark:
R surround lighting: the exterior lighting
remains lit for 40 seconds after unlocking
with the SmartKey. If you start the engine,
the surround lighting is switched off and
automatic headlamp mode is activated
(Y page 99).
R exterior lighting delayed switch-off: the
exterior lighting remains lit for
60 seconds after the engine is switched off.
If you close all the doors and the trunk lid,
the exterior lighting goes off after
15 seconds.
X Press the = or ; button on the
steering wheel to select the Sett. menu.
X Press the :
or 9
button to select the
Lights submenu.
X Press a to confirm.
X Press the : or 9
button to select the
Locator Lighting function.
You will see the selected setting: Enabled
or Disabled.
X Press the a button to save the setting.
Deactivating delayed switch-off of the
exterior lighting temporarily:
X Before leaving the vehicle, turn the
SmartKey to position 0

in the ignition lock.
X Turn the SmartKey to position 2 in the
ignition lock.
The exterior lighting delayed switch-off is
deactivated.
Delayed switch-off of the exterior lighting is
reactivated the next time you start the
engine.
i Depending on your vehicle's equipment,
when the surround lighting and delayed
switch-off exterior lighting are on, the
following light up: R
Parking lamps
R Front fog lamps
R Low-beam headlamps
R Daytime running lamps
R Side marker lamps
R Surround lighting in the exterior mirrors
Activating/deactivating the interior
lighting delayed switch-off
If you activate the Interior Lighting
Delay function, the interior lighting remains
on for 20seconds after you remove the
SmartKey from the ignition lock.
X Press the = or ; button on the
steering wheel to select the Sett. menu.
X Press the : or 9
button to select the
Lights submenu.
X Press a to confirm.
X Press the :
or 9

button to select the
Interior Lighting Delay function.
You will see the selected setting: Enabled
or Disabled.
X Press the a button to save the setting.
Vehicle Activating/deactivating the automatic
door locking mechanism
X
Press the = or ; button on the
steering wheel to select the Sett menu.
X Press the :
or 9
button to select the
Vehicle submenu.
X Press a to confirm.
X Press the :
or 9

button to select the
Automatic Door Lock function.
You will see the selected setting: Enabled
or Disabled.
X Press the a button to save the setting.
If you select the Automatic Door Lock
function, the
vehicle

is centrally locked above
a speed of around 9 mph (15 km/h).
i For further information on the automatic
locking feature, see ( Y page 74).198
Menus and submenus
On-board computer and displays
ProCarManuals.com

This display message will only appear if all LEDs have failed.
Display messages Possible causes/consequences and
M Solutionsb
Check Left
Cornering Light
 or 
Check Right
Cornering Light The left or right-hand cornering light is defective.
X
Check whether you are permitted to replace the bulb yourself
(Y page 104).
or
X Visit a qualified specialist workshop. b
Check Left Low
Beam or Check
Right Low Beam The left or right-hand low-beam headlamp is defective.
X
Check whether you are permitted to replace the bulb yourself
(Y page 104).
or
X Visit a qualified specialist workshop. b
Check Rear Left
Turn Signal or 
Check Rear Right
Turn Signal The rear left-hand or rear right-hand turn signal is defective.
X
Check whether you are permitted to replace the bulb yourself
(Y page 104).
or
X Visit a qualified specialist workshop. b
Check Front Left
Turn Signal or 
Check Front Right
Turn Signal The front left-hand or front right-hand turn signal is defective.
X
Check whether you are permitted to replace the bulb yourself
(Y page 104).
or
X Visit a qualified specialist workshop. b
Check Left Mirror
Turn Signal or 
Check
Right
Mirror
Turn Signal The turn signal in the left-hand or right-hand exterior mirror is
defective.
X
Check whether you are permitted to replace the bulb yourself
(Y page 104).
or
X Visit a qualified specialist workshop. b
Check Center
Brake
Lamp The high-mounted brake lamp is faulty.
X
Check whether you are permitted to replace the bulb yourself
(Y page 104).
or
X Visit a qualified specialist workshop. Display messages
209On-board computer and displays Z
ProCarManuals.com

Checking and adding other service
products
Checking coolant level G
WARNING
The engine cooling system is pressurized,
particularly when the engine is warm. When
opening the cap,
you could be scalded by hot
coolant spraying out. There is a risk of injury.
Let the engine cool down before opening the
cap. Wear eye and hand protection when
opening the cap. Open the cap slowly half a
turn to allow pressure to escape.
! The coolant may only be checked and
corrected when the engine is cool (coolant
temperature below 104 ‡ (40 †).
Checking the coolant when the coolant
temperature is above 104 ‡ (40 †) may
result in damage to the engine or to the
engine cooling system. Example
X
Park the vehicle on a level surface.
Only check the coolant level when the
vehicle is on

a level surface and the engine
has cooled down.
X Turn the SmartKey to position 2 in the
ignition lock (Y page 135).
X Check the coolant temperature display in
the instrument cluster.
The coolant temperature must be below
104 ‡ (40 †).
X Turn the SmartKey to position
0 (

Y page 135) in the ignition lock. X
Slowly turn cap : half a turn counter-
clockwise to allow excess pressure to
escape.
X Turn cap : further counter-clockwise
and
remove it.
If the coolant is at the level of marker bar
= in the filler neck when cold, there is
enough coolant in coolant expansion
tank ;.
X If necessary, add coolant that has been
tested and approved by Mercedes-Benz.
X Replace cap : and turn

it clockwise as far
as it will go.
For further information on coolant, see
(Y page 333).
Adding washer fluid to the windshield
washer system/headlamp cleaning
system G
WARNING
Windshield washer concentrate is highly
flammable. If it comes into contact with hot
engine components or the exhaust system it
could ignite. There is a risk of fire and injury.
Make sure that no windshield washer
concentrate is spilled next to the filler neck. Example
X
To open: pull cap : upwards by the tab.
X Add the premixed washer fluid.
X To close:
press cap :
onto the filler neck
until it engages. Engine compartment
269
Maintenance and care Z
ProCarManuals.com

The washer fluid reservoir is used for both the
windshield washer
system
and the headlamp
cleaning system.
The recommended minimum amount when
topping up is 1 liter. If the water level drops
below this, a message appears in the
multifunction display prompting you to refill
the washer fluid ( Y page 223).
Further information on windshield washer
fluid/antifreeze ( Y page 334).Maintenance
ASSYST PLUS
Service messages The ASSYST PLUS service interval display
informs you of the next service due date.
Information on
the

type of service and service
intervals (see the separate Maintenance
Booklet).
You can obtain further information from an
authorized Mercedes-Benz Center or at
http://www.mbusa.com (USA only).
i The ASSYST PLUS service interval display
does not show any information on the
engine oil level. Observe the notes on the
engine oil level ( Y page 267).
The multifunction display shows a service
message for several seconds, e.g.:
R Next Service A in .. Days
R Service A Due
R Service A Exceeded by .. Days
Depending on the operating conditions of the
vehicle, the remaining time or distance until
the next service due date is displayed.
The letter A or B, possibly in connection with
a number or another letter, shows the type of
service. A stands for a minor service and B for
a major service.
You can obtain further information from an
authorized Mercedes-Benz Center.
The ASSYST PLUS service interval display
does not take into account any periods of time during which the battery is
disconnected.
Maintaining the time-dependent service
schedule:
X
Note down the service due date displayed
in the multifunction display before
disconnecting the battery.
or
X After reconnecting the battery, subtract
the battery
disconnection

periods from the
service date shown on the display.
Hiding a service message X
Press % or a.
Displaying service messages X
Switch on the ignition.
X Using = or ;, select the Serv.
menu.
X Press 9 or : to select the ASSYST
PLUS submenu and

press a to confirm.
The service due date appears in the
multifunction display.
Information about Service Resetting the ASSYST PLUS service
interval display
!
If the ASSYST PLUS service interval
display has been inadvertently reset, this
setting can be corrected at a qualified
specialist workshop.
Have service work

carried out as described
in the Maintenance Booklet. This may
otherwise lead to increased wear and
damage to the major assemblies or the
vehicle.
A qualified specialist workshop, e.g. an
authorized Mercedes-Benz Center, will reset
the ASSYST PLUS service interval display
after the service work has been carried out.
You can also obtain further information on
maintenance work, for example. 270
Maintenance
Maintenance and care
ProCarManuals.com

i
Use antifreeze/corrosion inhibitor
according to MB approval 325.0 or 326.0. Windshield washer system and
headlamp cleaning system
Important safety notes G
WARNING
Windshield washer concentrate is highly
flammable. If it comes into contact with hot
engine components or the exhaust system it
could ignite. There is a risk of fire and injury.
Make sure that no windshield washer
concentrate is spilled next to the filler neck.
! Only use washer fluid that is suitable for
plastic lamp lenses, e.g. MB SummerFit or
MB WinterFit. Unsuitable washer fluid
could damage the plastic lenses of the
headlamps.
! Do not add
distilled or de-ionized water to
the washer fluid container. Otherwise, the
level sensor may be damaged.
! Only MB SummerFit and MB WinterFit
washer fluid should be mixed together. The
spray nozzles may otherwise become
blocked.
When handling washer fluid, observe the
important safety notes on service products
(Y page 329).
At temperatures above freezing:
X Fill the washer fluid reservoir with a mixture
of water and windshield washer fluid, e.g.
MB SummerFit.
Add 1 part MB SummerFit to 100 parts water. At temperatures below freezing:
X
Fill the washer fluid reservoir with a mixture
of water and washer fluid, e.g. MB
WinterFit.
Adapt the mixing ratio to the outside
temperature.
R Down to 14 ‡ (Ò

10 †): mix 1 part MB
WinterFit with 2 parts water.
R Down to Ò4 ‡ (Ò20 †): mix 1 part MB
WinterFit with 1 part water.
R Down to Ò20.2 ‡ (Ò29 †): mix 2 parts MB
WinterFit with 1 part water.
i Add windshield washer fluid, e.g. MB
SummerFit or MB WinterFit, to the washer
fluid all year round. Climate control system refrigerant
Important safety notes Type of refrigerant
The instruction label about types of
refrigerants can be found on the radiator
cross member.
Refrigerant R-134a
!
Only use refrigerant R-134a and PAG oil
(part number A0019890803) which has
been approved by Mercedes-Benz. The
approved R-134a PAG

oil may not be mixed
with other conventional PAG oils.
Otherwise, the climate control system may
be damaged.
Service work, such as topping-up refrigerant
or replacing components, may only be carried
out by a qualified specialist workshop. All
applicable regulations must be adhered to,
SAE standard J639 included.
Always have work on the climate control
system carried out at a qualified specialist
workshop. 334
Service products and filling capacitiesTechnical data
ProCarManuals.com