steering MERCEDES-BENZ A CLASS 2012 Repair Manual

X
Remove rust, e.g. with a wire brush.
X Remove dirt with a clean, lint-free cloth or
a brush.
X After cleaning, lightly oil or grease ball cou-
pling :.
X Check that the vehicle's trailer tow hitch is
working properly.
i Maintenance of the ball coupling and
trailer tow hitch can also be performed at
a qualified specialist workshop, e.g. a
Mercedes-Benz Service Centre. Interior care
Cleaning the display !
For cleaning, do not use any of the fol-
lowing:
R alcohol-based thinner or petrol
R abrasive cleaning agents
R commercially-available
household clean-
ing agents
These may damage the display surface. Do
not put pressure on the display surface
when cleaning. This could lead to irrepara-
ble damage to the display.
X Before cleaning the display, make sure that
it is switched off and has cooled down.
X Clean the display surface using a commer-
cially available microfibre cloth and TFT/
LCD display cleaner.
X Dry the display surface using a dry micro-
fibre cloth. Cleaning the plastic trim G
WARNING
Care products and cleaning agents containing
solvents
can cause surfaces in the cockpit to
become porous. This could result in plastic
parts breaking away when the airbags are
deployed. There is a danger of injury.
Do not use care products and cleaning agents
containing solvents to clean the cockpit.
! Do not affix the following to plastic surfa-
ces:
R stickers
R films
R scented oil bottles or similar items
You could otherwise damage the plastic.
! Do not allow cosmetics, insect repellent
or sunscreen to come in contact with the
plastic trim. This maintains the high-quality
look of the surfaces.
X Wipe the plastic trim with a damp, lint-free
cloth, e.g. a microfibre cloth.
X Heavy soiling: use car care and cleaning
products recommended and approved by
Mercedes-Benz.
The surface may change colour tempora-
rily. Wait until the surface is dry again.
Cleaning the steering wheel and gear or
selector lever X
Thoroughly wipe with a damp cloth or use
leather

care agents that have been recom-
mended and approved by Mercedes-Benz.
Cleaning wooden trim and trim ele-
ments !
Do
not use solvent-based cleaning agents
such as tar remover, wheel cleaners, pol-
ishes or waxes. There is otherwise a risk of
damaging the surface. Care
295
Maintenance and care Z

The maximum permissible distance which
can
be driven in run-flat mode is counted from
the moment the tyre pressure loss warning
appears in the multifunction display.
You must not exceed a maximum speed of
80 km/h.
i When replacing one or all tyres, make
sure that you use only:
R the tyre size specified for the vehicle and
R tyre(s) marked "MOExtended"
If a tyre has gone flat and cannot be
replaced with an MOExtended tyre, a
standard tyre may be used as a temporary
measure. Make sure that you use the
proper size and type (summer or winter
tyre).
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.
Important safety notes G
WARNING
When driving in emergency mode, the driving
characteristics
deteriorate, e.g. when corner-
ing, accelerating quickly and when braking.
There is a risk of accident.
Do not exceed the stated maximum speed.
Avoid abrupt steering and driving manoeu-
vres, and driving over obstacles (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. TIREFIT kit
Important safety notes G
WARNING
In the following situations, the tyre sealant is
unable
to provide sufficient breakdown assis-
tance, as it is unable to seal the tyre properly:
R there are cuts or punctures in the tyre
larger than those mentioned above.
R the wheel rim is damaged.
R you have driven at very low tyre pressures
or on a flat tyre.
There is a risk of accident.
Do not drive any further. Contact a qualified
specialist workshop. G
WARNING
The tyre sealant is harmful and causes irrita-
tion. It must not come into contact with your
skin,

eyes or clothing or be swallowed. Do not
inhale TIREFIT fumes. Keep tyre sealant away
from children. There is a risk of injury.
If you come into contact with the tyre sealant,
observe the following:
R Rinse off the tyre sealant from your skin
immediately with water.
R If the tyre sealant comes into contact with
your eyes, immediately rinse them thor-
oughly with clean water.
R If tyre sealant is swallowed, immediately
rinse your mouth out thoroughly and drink
plenty of water. Do not induce vomiting,
and seek medical attention immediately.
R Immediately change out of clothing which
has come into contact with tyre sealant.
R If an allergic reaction occurs, seek medical
attention immediately. Flat tyre
301Breakdown assistance Z

Position number
B identifies the charged battery of the other vehicle or an equivalent jump-
starting device.
X Press together cover : of positive clamp ; and slide it back.
X Connect positive terminal ; on your vehicle to positive terminal = of donor battery B
using the jump lead, beginning with your own battery.
X Start the engine of the donor vehicle and run it at idling speed.
X Connect negative terminal ? of donor battery B to earth point A of your vehicle using
the jump lead, connecting the jump lead to donor battery B first.
X Start the engine.
X Before disconnecting the jump leads, let the engines run for several minutes.
X First, remove the jump leads from earth point A
and negative terminal ?, then from pos-
itive clamp ; and positive terminal =. Begin each time at the contacts on your own vehicle
first.
X Close cover : of positive clamp ; after removing the jump leads.
X Have the battery checked at a qualified specialist workshop.
i Jump-starting is not considered to be a normal operating condition.
i Jump-starting cables and further information regarding jump starting can be obtained at
any qualified specialist workshop. Towing and tow-starting
Important safety notes
G
WARNING
Safety-relevant functions are restricted or not
available if:
R the engine is not running.
R the brake system or the power steering is
malfunctioning
R the

voltage supply or the vehicle's electrical
system is malfunctioning.
If your vehicle is towed, significantly greater
force may be required to steer the vehicle or
to brake. There is a risk of an accident.
In such circumstances, use a towing bar.
Make sure that the steering is moving freely
before towing. G
WARNING
If the weight of the vehicle to be towed or tow-
started is greater than the permissible gross
weight of your vehicle:
R the towing eye could detach itself
R the

vehicle/trailer combination could over-
turn.
There is a risk of an accident.
When towing or tow-starting another vehicle,
its weight should not be greater than the per-
missible gross weight of your vehicle.
Information on your vehicle's gross vehicle
weight rating can be found on the vehicle
identification plate ( Y page 338). G
WARNING
The vehicle is braked when the HOLD function
or DISTRONIC PLUS is activated. Therefore,
deactivate

HOLD and DISTRONIC PLUS if the
vehicle is to be towed. 310
Towing and tow-starting
Breakdown assistance

Vehicles with a TIREFIT kit: the towing eye
is
located under the tyre inflation compres-
sor.
X Press the mark on cover : inwards in the
direction of the arrow.
X Remove cover : from the opening.
X Screw the towing eye in clockwise to the
stop and tighten it.
Vehicles with a trailer tow hitch do not have
a bracket for the screw-in towing eye at the
back.

If you intend to use the vehicle for tow-
ing, fold out the ball coupling ( Y page 203)
and secure the towbar to it.
Removing the towing eye X
Loosen the towing eye and unscrew it.
X Attach cover : to the bumper and press
until it engages.
X Place the towing eye in the stowage well
under the luggage compartment floor
(Y page 299).
X Vehicles with a TIREFIT kit: replace the tyre
inflation compressor. Towing the vehicle with the front axle
raised
Only vehicles without 4MATIC can be
towed with the front axle raised.
! Vehicles

with 4MATIC must not be towed
with the front or rear axle raised; otherwise,
the transmission may be damaged.
Vehicles with 4MATIC may either be towed
away with both axles on the ground or be loa-
ded up and transported.
! The ignition must be switched off if you
are towing the vehicle with the front axle
raised. Intervention by ESP ®
could other-
wise damage the brake system.
X Turn the key to position 2 in the ignition
lock.
X When the vehicle is stationary, depress the
brake pedal and keep it depressed. X
Vehicles with manual transmission:
depress the clutch pedal fully and shift to
neutral.
or
X Vehicles with automatic transmission:
shift the automatic transmission to posi-
tion P.
X Release the brake pedal.
X Release the electric parking brake.
X Deactivate automatic locking
(Y page 223).
X Switch on the hazard warning lamps
(Y page 108).
X Turn the key in the ignition lock to position
0 and leave the key in the ignition lock.
When towing your vehicle with the front axle
raised, it is important that you observe the
safety instructions ( Y page 310). Towing the vehicle with both axles on
the ground
G
WARNING
The power assistance for the steering and the
brake force booster do not work when the
engine is not running. You will then need
much

more effort to brake and steer the vehi-
cle. Adapt your style of driving accordingly.
i In order to signal a change of direction
when towing with the hazard warning lamps
switched on, use the combination switch as
usual. In this case, only the turn signals for
the desired direction flash. When you reset
the combination switch, the hazard warn-
ing lamps start flashing again. 312
Towing and tow-starting
Breakdown assistance

Vehicles with automatic transmission:
the
automatic transmission automatically shifts
to position P when you open the driver's or
front-passenger door or when you remove the
key from the ignition lock. In order to ensure
that the automatic transmission stays in posi-
tion N when towing the vehicle, you must
observe the following points:
X Make sure that the vehicle is stationary.
X Turn the key to position 2 in the ignition
lock.
X Depress and hold the brake pedal.
X Shift the automatic transmission to posi-
tion N.
Vehicles with manual transmission:
X Turn the key to position 2 in the ignition
lock.
X Depress and hold the brake pedal.
X Engage neutral.
Vehicles with manual or automatic trans-
mission:
X Leave the key in position 2 in the ignition
lock.
X Release the brake pedal.
X Release the electric parking brake.
X Switch on the hazard warning lamps
(Y page 108).
It is important that you observe the safety
instructions when towing away your vehicle
(Y page 310). Transporting the vehicle
! Only

lash the vehicle down by the wheels
or wheel rims, not by parts of the vehicle
such as axle or steering components. Oth-
erwise, the vehicle could be damaged. X
Vehicles with manual transmission:
shift to neutral.
X Vehicles with automatic transmission:
turn the key to position 2 in the ignition
lock.
X Move the transmission to position N.
As soon as the vehicle is loaded:
X Prevent the vehicle from rolling away by
applying the electric parking brake.
X Vehicles with manual transmission:
engage first or reverse gear.
X Vehicles with automatic transmission:
shift the transmission to position P.
X Turn the key to position 0 in the ignition
lock and remove it.
X Secure the vehicle.
The towing eyes or trailer tow hitch can be
used
to pull the vehicle onto a trailer or trans-
porter if you wish to transport it. Notes for 4MATIC vehicles
! Vehicles

with 4MATIC must not be towed
with the front or rear axle raised; otherwise,
the transmission may be damaged.
Vehicles with 4MATIC may only be either
towed away with both axles on the ground or
be loaded up and transported.
If the vehicle has transmission damage or
damage to the front or rear axle, have it trans-
ported on a transporter or trailer.
In the event of damage to the electrical
system
If the battery is defective, the automatic
transmission will be locked in position P. To
shift the automatic transmission to position
N, you must provide power to the vehicle's
electrical system in the same way as when
jump-starting (Y page 308).
Have the vehicle transported on a transporter
or trailer. Towing and tow-starting
313
Breakdown assistance Z

does not exceed the maximum permissible
speed for the M+S tyres(Y page 172).
When you have fitted the M+S tyres:
X
Check the tyre pressures ( Y page 321).
X Restart the tyre pressure loss warning sys-
tem (Y page 323).
For more information on driving with the
emergency spare wheel, see (Y page 332). Snow chains
G
WARNING
If snow chains are fitted to the rear wheels,
they may scrape against the vehicle body or
chassis components. This could cause dam-
age

to the vehicle or the tyres. There is a risk
of an accident.
To avoid hazardous situations:
R never fit snow chains on the rear wheels
R always fit snow chains in pairs to the front
wheels.
! Vehicles with steel wheels: if you fit
snow chains on steel wheels, you may dam-
age the hub caps. Remove the hub caps
from the relevant wheels before fitting the
snow chains.
For safety reasons, Mercedes-Benz recom-
mends that you only use snow chains that
have been specially approved for your vehicle
by Mercedes-Benz, or that are of a corre-
sponding standard of quality.
If you intend to fit snow chains, please bear
the following points in mind:
R snow chains cannot be fitted to all wheel-
tyre combinations. Permissible wheel-tyre
combinations (Y page 329).
R only use snow chains when the road sur-
face is completely snow-covered. Remove
the snow chains as soon as possible when
you come to a road that is not snow-cov-
ered. R
local regulations may restrict the use of
snow

chains. Observe the appropriate reg-
ulations if you wish to fit snow chains.
R do not exceed the maximum permissible
speed of 50 km/h.
R when snow chains are fitted, never use
Active Parking Assist (Y page 186).
i You may wish to deactivate
ESP ®
(Y page 65) when pulling away with
snow chains fitted. This way you can allow
the wheels to spin in a controlled manner,
achieving an increased driving force (cut-
ting action).
Information about driving with an emergency
spare wheel ( Y page 332). Tyre pressure
Tyre pressure specifications
G
WARNING
Tyres with too low or too high tyre pressure
contain the following hazards:
R they

can burst, in particular if the vehicle is
heavily laden or when driven at high
speeds.
R the tyres can wear excessively and/or
unevenly, which can severely impair tyre
traction.
R the driving, steering and braking character-
istics may be severely impaired.
There is a risk of accident.
Follow recommended tyre inflation pressures
and check the pressure of all the tyres includ-
ing the spare wheel:
R at least every two weeks
R if the load changes
R before beginning a long journey
R for changed operating conditions, e.g. off-
road driving
If necessary, correct the tyre pressure. Tyre pressure
321
Wheels and tyres Z

i
The tyre pressure values given for low
loads are minimum values which offer you
good ride comfort characteristics.
However,
you can also use the values given
for higher loads. These are permissible and
will not adversely affect the running of the
vehicle. Tyre pressure loss warning system
Important safety notes While the vehicle is in motion, the tyre pres-
sure loss warning system monitors the set
tyre pressure using the rotational speed of
the

wheels. This enables the system to detect
significant pressure loss in a tyre. If the speed
of rotation of a wheel changes as a result of
a loss of pressure, a corresponding warning
message will appear in the multifunction dis-
play.
The tyre pressure warning system does not
warn you of an incorrectly set tyre pressure.
Observe the notes on the recommended tyre
pressure ( Y page 321).
The tyre pressure loss warning system does
not replace the need to regularly check your
vehicle's tyre pressures, since an even loss of
pressure on several tyres at the same time
cannot be detected by the tyre pressure loss
warning system.
The tyre pressure monitor is not able to warn
you of a sudden loss of pressure, e.g. if the
tyre is penetrated by a foreign object. In the
event of a sudden loss of pressure, bring the
vehicle to a halt by braking carefully. Avoid
abrupt steering manoeuvres.
The function of the tyre pressure loss warning
system is limited or delayed if:
R snow chains are fitted to your vehicle's
tyres.
R road conditions are wintry.
R you are driving on sand or gravel.
R you adopt a very sporty driving style (cor-
nering at high speeds or driving with high
rates of acceleration). R
you
are towing a very heavy or large trailer.
R you are driving with a heavy load (in the
vehicle or on the roof).
Restarting the tyre pressure loss warn-
ing system Restart the tyre pressure loss warning system
if you have:
R
changed the tyre pressure
R changed the wheels or tyres
R fitted new wheels or tyres
X Before restarting, make sure that the tyre
pressures

are set properly on all four tyres
for the respective operating conditions.
The recommended tyre pressures can be
found in the table on the fuel filler flap.
The tyre pressure loss warning system can
only give reliable warnings if you have set
the correct tyre pressure. If an incorrect
tyre pressure is set, these incorrect values
will be monitored.
X Observe the notes on tyre pressure
(Y page 321).
X Make sure that the key is in posi-
tion 2(Y page 143) in the ignition lock.
X Press the =
or ; button on the steer-
ing wheel to select the Service menu.
X Press the 9 or : button to select
Tyre pressure.
X Press the a button.
The Run Flat Indicator active
Restart

with OK message appears in the
multifunction display.
If you wish to confirm the restart:
X Press the a button.
The Tyre press. now OK? message
appears in the multifunction display.
X Press the 9 or : button to select
Yes.
X Press the a button.
The Run Flat Indicator restarted
message appears in the multifunction dis-
play. Tyre pressure
323
Wheels and tyres Z