ignition MERCEDES-BENZ B-CLASS HATCHBACK 2008 Repair Manual

Troubleshooting
237Headlamps
Problem Possible cause/consequence Suggested solutions
The headlamps or the turn signals
in the exterior mirrors are misted
up on the inside. Air humidity is very high. X
Drive with the headlamps switched on.
The headlamps are demisted after a short distance. The headlamp housing is not
sealed and moisture has been
able to enter. X
Have the headlamps checked at a qualified specialist workshop. Windscreen wipers
Problem Possible cause/consequence Suggested solutions
The windscreen wipers are jam-
med. Leaves or snow, for example, may
be obstructing the windscreen
wiper movement. The wiper
motor has been deactivated. X
For safety reasons, you should remove the key from the ignition
lock.
X Remove the cause of the obstruction.
X Switch the windscreen wipers back on. The windscreen wipers fail com-
pletely. G
Risk of accident
The windscreen wiper drive is
malfunctioning. X
Select another wiper speed on the combination switch.
X Have the windscreen wipers checked at a qualified specialist work-
shop. Practical advice
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Troubleshooting
239Key
Problem Possible cause/consequence Suggested solutions
You cannot lock or unlock the
vehicle using the key. The key batteries are discharged
or nearly discharged. X
Point the tip of the key at the driver's door handle from close range
and try to unlock or lock the vehicle again.
If this does not work:
X Unlock the vehicle using the emergency key element
(Y page 241).
X Check the key batteries (Y page 244) and replace them if neces-
sary (Y page 244). The key is faulty. X
Unlock the vehicle using the emergency key element
(Y page 241).
X Have the key checked at a qualified specialist workshop. The battery charge indicator lamp
of the key does not go on during
the test. The key batteries are discharged. X
Change the batteries (Y page 244).You have lost a key. X
Have the key cancelled at a Mercedes-Benz Service Centre.
X Report the loss immediately to the vehicle insurers.
X If necessary, have the manual locks changed too. You have lost the emergency key
element. X
Report the loss immediately to the vehicle insurers.
X If necessary, have the manual locks changed too. The engine cannot be started
using the key. The steering lock is mechanically
blocked. X
Remove the key and reinsert it into the ignition lock. While doing
this, turn the steering wheel in both directions. Practical advice
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Locking/unlocking in an emergency
241Locking/unlocking in an emergency
Emergency key
If the vehicle can no longer be locked or
unlocked with the key, use the emergency
key element.
If you use the emergency key element to
unlock and open the driver's door, the anti-
theft alarm system* will be triggered
(Y page 57).
There are several ways to turn off the alarm:
X Press the korj button on the key.
or
X Insert the key into the ignition lock.
If you unlock the vehicle using the emergency
key element, the fuel filler flap will not be
unlocked automatically.
X To unlock the fuel filler flap: insert the
key in the ignition lock. Releasing and removing the emergency
key element X
Push release catch 1in the direction of
the arrow and at the same time remove
emergency key element 2from the key. Unlocking the vehicle
If the vehicle can no longer be unlocked cen-
trally with the key:
X Remove the emergency key element from
the key (Y page 241). $
To unlock
X Insert the emergency key element into the
lock of the driver's door as far as it will go.
X Firmly turn the emergency key element
anti-clockwise as far as it will go to position
$ and hold it in this position.
i On right-hand-drive vehicles, turn the
emergency key element clockwise.
X Pull the door handle firmly.
The locking knob pops up.
The door is unlocked. Practical advice
* optional
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Replacing the wiper blades
250
Changing the bulbs in the licence plate
lamps X
Switch off the lights.
X Open the tailgate.
X Using a screwdriver, loosen both sides of
licence plate lamp 1in the direction of the
arrow.
X Remove licence plate lamp 1.
X Replace the bulb.
X Insert licence plate lamp 1and press it in
until it engages. Replacing the wiper blades
Windscreen wiper blades
G
Risk of accident
The windscreen will no longer be wiped
properly if the wiper blades are worn. This
could prevent you from observing the traffic
conditions, thereby causing an accident.
Replace the wiper blades twice a year, ide-
ally in spring and autumn. G
Risk of accident
The wiper arms could start moving and
cause an injury if you leave the windscreen
wipers switched on.
Remove the key from the ignition lock
before replacing the wiper blades.
! To avoid damaging the windscreen wiper
blades, make sure that you touch only the
wiper arm of the windscreen wiper.
Removing X
Remove the key from the ignition lock.
X Fold the wiper arm away from the wind-
screen. X
Press both release clips 2.
X Fold wiper blade 1in the direction of
arrow 3away from wiper arm 4.
X Remove wiper blade 1in the direction of
the arrow 5.
Fitting Practical advice
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Replacing the wiper blades
251
X
Position the new wiper blade 1with
recess 6on lug 5.
X Fold wiper blade 1in the direction of
arrow 3onto the wiper arm, until retaining
clips 2engage in bracket 4.
X Make sure that wiper blade 1is seated
correctly.
X Fold the wiper arm back onto the wind-
screen. Rear window wiper blade
G
Risk of injury
The wiper arm could be set in motion and
injure you if the windscreen wipers are
switched on.
Remove the key from the ignition lock
before replacing the wiper blade. Removing X
Remove the key from the ignition lock.
X Fold the wiper arm away from the rear win-
dow until it engages.
X Turn wiper blade 1in the direction of
arrow 2until it is released from the
retainer on the wiper arm.
X Remove wiper blade 1.
Fitting X
Push the new wiper blade 1onto the wiper
arm until you feel it engage.
X Make sure that wiper blade 1is seated
correctly. X
Turn wiper blade 1parallel to the wiper
arm.
X Fold the wiper arm back onto the rear win-
dow. Adjusting the spraying nozzles
Check the spraying nozzles setting regularly.
If they have moved, you can readjust them
yourself. G
Risk of injury
The wiper arms could start moving and
cause an injury if you leave the windscreen
wipers switched on.
Remove the key from the ignition lock
before adjusting the spraying nozzles.
! Do not use any tools, e.g. a needle, to
adjust the spraying nozzles. There is other-
wise a risk of damaging the spraying noz-
zles. Practical advice
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Flat tyre
252X
Swivel spraying nozzles 1upwards or
downwards.
X Wipe briefly with washer fluid to test them
(Y page 82).
The spraying nozzles are correctly posi-
tioned if the stream of water hits the wind-
screen approximately in the centre. Flat tyre
Flat tyre equipment variants
Your vehicle may be equipped with:
R a TIREFIT kit (Y page 200)
R a "Minispare" emergency spare
wheel* (Y page 202)
R a spare wheel* (Y page 202)
R the MOExtended run-flat sys-
tem* (Y page 262) Preparing the vehicle
i Vehicle preparation is not necessary on
vehicles with MOE tyres*.
X Stop your vehicle as far away from traffic
as possible on solid, non-slippery, level
ground.
X Switch on the hazard warning lamps.
X Apply the handbrake.
Vehicles with manual transmission X
Shift to either first or reverse gear. Vehicles with AUTOTRONIC* X
Move the selector lever to P.
For all vehicles 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 Switch off the engine.
X Remove the key from the ignition lock.
X Get out of the vehicle.
X Close the driver’s door.
X Place the warning triangle ( Ypage 200) at
a suitable distance. Observe legal require-
ments. Practical advice
* optional
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Flat tyre
254
i
Your vehicle may be equipped with one of
two different air pumps. Version 1 can be
identified by the flap, behind which the
hose with the pressure gauge and cable are
located; version 2 has a pressure gauge
integrated in the electric air pump.
Type 1 1
TIREFIT sealant filler bottle
2 Flap
3 Recess
4 On/off switch
5 Electric connector with cable
6 Air pump hose
7 Flange X
Open flap 2on the electric air pump.
X Pull connector 5and air pump hose 6
from the housing.
X Screw air pump hose 6onto flange 7of
TIREFIT filler bottle 1.
X Place TIREFIT sealant filler bottle 1head
downwards into recess 3of the electric
air pump. 8
Filler hose
9 Valve
X Remove the cap from valve 9on the faulty
tyre. a
Pressure release screw
b Pressure gauge
X Make sure pressure release screw aon
pressure gauge bis fully closed.
X Screw filler hose 8onto valve 9.
X Insert plug 5into the socket of the ciga-
rette lighter* (Y page 162) or into a 12 V
power socket in your vehicle .
X Turn the key to position 2(Y page 62) in
the ignition lock.
X Press on/off switch 4on the electric air
pump to I.
The electric air pump is switched on. The
tyre is inflated.
i First, TIREFIT is pumped into the tyre. The
pressure can briefly rise to around 5 bar. Practical advice
* optional
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Flat tyre
256 H
Environmental note
Have the used TIREFIT kit disposed of pro-
fessionally, e.g. at a Mercedes-Benz
Service Centre.
X Have the TIREFIT kit replaced every four
years at a qualified specialist workshop,
e.g. a Mercedes-Benz Service Centre.
Type 2 1
TIREFIT sealant filler bottle
2 Recess
3 On/off switch
4 Electric connector with cable
5 Air pump hose
6 Flange X
Pull connector 4and air pump hose 5
from the housing.
X Screw air pump hose 5onto flange 6of
TIREFIT filler bottle 1.
X Place TIREFIT sealant filler bottle 1head
downwards into recess 2of the electric
air pump. 7
Valve
8 Filler hose
X Remove the cap from valve 7on the faulty
tyre.
X Screw filler hose 8onto valve 7. X
Insert plug 4into the socket of the ciga-
rette lighter* (Y page 162) or into a 12 V
power socket in your vehicle .
X Turn the key to position 2(Y page 62) in
the ignition lock.
X Press on/off switch 3on the electric air
pump to I.
The electric air pump is switched on. The
tyre is inflated.
i First, TIREFIT is pumped into the tyre. The
pressure can briefly rise to around 5 bar.
Do not switch off the electric pump dur-
ing this phase.
X Let the electric pump run for five minutes.
The tyre should then have a pressure of at
least 1.8 bar.
! Do not operate the electric air pump for
longer than eight minutes at a time without
a break. Otherwise, it may overheat.
The air pump can be operated again once
it has cooled down. Practical advice
* optional
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Battery
264 step out of the vehicle first and touch the
bodywork.
R Do not wipe the battery using a cloth. The
battery could be destroyed as a result of
electrostatic charge or due to flying
sparks.
! Switch off the engine and remove the key
before disconnecting the terminal clamps
from the battery. Otherwise, you may
destroy electronic components, such as
the alternator.
i Mercedes-Benz recommends that you
have all work involving the battery, e.g.
removing, charging and replacing, carried
out at a qualified specialist workshop, e.g.
a Mercedes-Benz Service Centre.
Installation location of the battery Your vehicle is equipped with a battery in the
footwell in front of the front-passenger seat.
The main fuse box is also located there. 1
Retaining screw
2 Cap
X Remove the floormat*.
X Remove retaining screw 1by turning it
anti-clockwise, e.g. by using a coin.
X Lift up cover 2. 3
Negative terminal
4 Positive terminal Disconnecting the battery
G
Risk of accident
If the battery is disconnected:
R the brake boosting effect will not be avail-
able. Greater braking force will then be
required and the brake pedal travel will
be longer. If necessary, depress the
brake pedal with maximum force.
R you will no longer be able to turn the key
in the ignition lock.
R the selector lever is locked in position P
on vehicles with AUTOTRONIC*. Practical advice
* optional
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Battery
265
!
Always disconnect the battery in
the order described below. Never swap the
terminal clamps. Otherwise, you may dam-
age the vehicle electronics.
X Apply the handbrake and shift the selector
lever to position Pon vehicles with AUTO-
TRONIC*.
X Switch off all electrical consumers.
X Turn the key to position 0(Y page 62) in
the ignition lock and remove it.
X Remove the negative terminal clamp from
the battery.
X Remove the cover from the positive termi-
nal clamp.
X Remove the positive terminal clamp from
the battery.
X Disconnect the breather hose. Removing the battery
X Disconnect the battery ( Ypage 264).
X Loosen the bolt which holds the battery in
place.
X Remove the battery. Charging and fitting the battery
G
Risk of injury
Only charge the battery in a well-ventilated
area. As the battery is being charged, gases
can escape and generate minor explosions.
This may injure you and other persons or
cause damage to the paintwork or acid cor-
rosion on the vehicle.
You can obtain information about battery
chargers which allow the battery to be
charged when still installed from a qualified
specialist workshop, e.g. a Mercedes-Benz
Service Centre. G
Risk of injury
There is a risk of acid burns during the
charging process due to the gases which
escape from the battery. Do not lean over
the battery during the charging process. G
Risk of injury
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. These battery
chargers allow the battery to be charged
while it is still installed. However, the bat-
tery must always be disconnected first.
! Only use battery chargers with a maxi-
mum charging voltage of 14.8 V.
X Charge the battery. Observe the notes in
the operating instructions for your battery
charger.
X Refit the charged battery.
To do this, follow the steps described in
"Removing the battery" (Y page 265) in
reverse order. Practical advice
* optional
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