engine MERCEDES-BENZ E-Class SEDAN 2012 W212 Repair Manual

Adding DEFGWARNING
Make sure
R DEF does not come into contact with skin,
eyes, or clothing
R to keep DEF out of the reach of children
If you and/or others have come into contact
with DEF:
R If DEF has gotten into contact with eyes,
flush with plenty of water immediately and
seek medical help.
R Clean affected skin immediately with plenty
of water.
R If DEF was swallowed, rinse mouth
immediately with plenty of water and drink
plenty of water. Consult a physician.
GWARNING
If you open the DEF tank cap at high
temperatures, ammonia vapors can be
released.
Ammonia vapors have a pungent odor and are
particularly irritating to:
R skin
R mucous membranes
R eyes
You may experience a burning sensation in
your eyes, nose and throat, as well as
coughing and watering of the eyes.
Do not inhale any ammonia vapors that may
be released. Only refill the DEF tank in well
ventilated areas.
! Only use DEF that complies with
ISO 22241. Do not add any special
additives to DEF and do not thin DEF with
water. This could destroy the BlueTEC
exhaust gas aftertreatment.
If the outside temperature is lower than
Ò 11 †, damage may occur when topping up.
If DEF is frozen and there is an active warning
indicator, topping up may not be possible.
Park the vehicle in a warmer place, e.g. in a
garage, until DEF has become fluid again.
Filling is then possible again. Alternatively,
have the DEF tank refilled at a qualified
specialist workshop.
! Rinse surfaces that have come into
contact with DEF immediately with water or
remove DEF using a damp cloth and cold
water. If the DEF has already crystallized,
use a sponge and cold water to clean it. DEF
residues crystallize after time and
contaminate the affected surfaces.
! DEF is not a fuel additive and must not be
added to the fuel tank. If DEF is added to
the fuel tank, this can lead to engine
damage.
i If you are adding between maintenance
intervals, add approximately 1 gallon (3.8 l)
of DEF to the DEF tank. One gallon (3.8 l)
of DEF is approximately 2 DEF refill bottles.
Then, have the DEF supply checked and
filled completely if necessary. For this
purpose, Mercedes-Benz recommends a
qualified specialist workshop.
Further information on DEF ( Y page 387).
The DEF filler neck is under the trunk floor.XSwitch off the ignition.XOpen the trunk.XLift up the trunk floor ( Y page 286).XTurn DEF cap : counter-clockwise and
remove it.166RefuelingDriving and parking

Unintended vehicle movement can cause
serious personal injury or damage to the
vehicle or the vehicle drivetrain. To reduce
such risks, always do the following before
turning off the engine and leaving the vehicle:
R keep your right foot on the brake pedal.
R engage the parking brake.
R shift the automatic transmission to park
position P.
R slowly release the brake pedal.
R when parked on an incline, always turn the
front wheels towards the road curb.
R turn the SmartKey in the ignition lock to
position 0 and remove the SmartKey from
the ignition lock, or press the KEYLESS-GO
Start/Stop button.
R take the SmartKey with you and lock the
vehicle when leaving.
Switching off the engine
Important safety notes
GWARNING
Do not turn off the engine before the vehicle
has come to a complete stop. With the engine
not running, there is no power assistance for
the brake and steering systems. In this case,
it is important to keep in mind that a
considerably higher degree of effort is
necessary to brake and steer the vehicle.
GWARNING
Keep in mind that turning off the engine alone
only will shift the automatic transmission into
neutral position N automatically.
Always shift the automatic transmission into
park position P before turning off the engine.
Otherwise the vehicle could roll away which
could result in an accident and/or serious
personal injury.
Vehicles with manual transmissionXShift to either first gear or reverse gear R.XTurn the SmartKey to position 0 in the
ignition lock and remove it.
The immobilizer is activated.XApply the parking brake firmly.
Vehicles with automatic transmission
XShift the transmission to position P.
Using the SmartKey
XTurn the SmartKey to position 0 in the
ignition lock and remove it.
The immobilizer is activated.XApply the parking brake firmly.
i If you turn off the engine with the
SmartKey and then remove it from the
ignition lock or open a front door, the
automatic transmission shifts to P
automatically.
Using KEYLESS-GO
XPress the Start/Stop button (Y page 145).
The engine stops and all the indicator
lamps in the instrument cluster go out.XApply the parking brake firmly.
i If you use the Start/Stop button to switch
off the engine, the automatic transmission
shifts to N automatically. If you then open
the driver's or front-passenger door, the
automatic transmission shifts to P.
i In an emergency, the engine can be
turned off while the vehicle is in motion by
pressing and holding the Start/Stop button
for three seconds.
If you have started the engine with the Start/
Stop button and it cannot be switched off as
described:
Xremove the Start/Stop button from the
ignition lock.Xinsert the SmartKey into the ignition lock.
The engine switches off. The ignition is in
position 0.168ParkingDriving and parking

Parking brakeGWARNING
Engaging the parking brake while the vehicle
is in motion can cause the rear wheels to lock
up. You could lose control of the vehicle and
cause an accident. In addition, the vehicle's
brake lights do not light up when the parking
brake is engaged.
GWARNING
When leaving the vehicle, always remove the
SmartKey from the starter switch, take it with
you, and lock the vehicle. Do not leave
children unattended in the vehicle, or with
access to an unlocked vehicle. Children could
release the parking brake and/or shift the
automatic transmission out of park position
P , either of which could result in an accident
and/or serious personal injury.
XTo apply: depress parking brake ; firmly.
When the engine is running, the $ (USA
only) or J (Canada only) indicator lamp
lights up in the instrument cluster.XTo release: depress the brake pedal and
keep it depressed.XPull release handle :.
When the ignition is switched on or the
engine is running, the $ (USA only) or
J (Canada only) indicator lamp goes out
in the instrument cluster.Parking the vehicle for a long period
If you leave the vehicle parked for longer than
four weeks, the battery may be damaged by
exhaustive discharge.XConnect a trickle charger.
i You can obtain information about trickle
chargers from a qualified specialist
workshop, e.g. an authorized Mercedes-
Benz Center.
If you leave the vehicle parked for longer than
six weeks, the vehicle may suffer damage as
a result of lack of use.
XVisit a qualified specialist workshop and
seek advice.
Driving tips
General driving tips
Important safety notes
GWARNING
Always remember that you must concentrate
primarily on driving the vehicle. The driver's
concentration must always be directed
primarily at road traffic. For your own safety
and that of others, we recommend that you
stop the vehicle at a safe place and in
accordance with the traffic conditions before
making or accepting a phone call.
Comply with all legal requirements if you use
the telephone while driving. Use the hands-
free system and only use the telephone when
road, weather and traffic conditions permit. In
some jurisdictions, it is forbidden for drivers
to use mobile phones while driving.
Only operate the audio system or COMAND
(Cockpit Management and Data System) in
compliance with all legal requirements and
when the road, weather and traffic conditions
permit. You may otherwise not be able to
observe the traffic conditions, endangering
yourself and others.
Remember that your vehicle covers a distance
of 44 feet (approximately 14 m) a second
Driving tips169Driving and parkingZ

when it is traveling at only 30 mph
(approximately 50 km/h).
Drive sensibly – save fuel
Observe the following tips to save fuel:
XThe tires should always be inflated to the
recommended tire pressure.XRemove unnecessary loads.XRemove roof racks when they are not
needed.XWarm up the engine at low engine speeds.XAvoid frequent acceleration or braking.XHave all maintenance work carried out as
indicated by the service intervals in the
Service Booklet or by the service interval
display.
Fuel consumption also increases when
driving in cold weather, in stop-and-go traffic
and in mountainous terrain.
Drinking and driving
GWARNING
Drinking and driving and/or taking drugs and
driving are very dangerous combinations.
Even a small amount of alcohol or drugs can
affect your reflexes, perceptions and
judgment.
The possibility of a serious or even fatal
accident are greatly increased when you drink
or take drugs and drive.
Do not drink or take drugs and drive or allow
anyone to drive who has been drinking or
taking drugs.
Pedals
GWARNING
Make sure absolutely no objects are
obstructing the pedals' range of movement.
Keep the driver's footwell clear of all
obstacles. If there are any floormats or
carpets in the footwell, make sure that the
pedals still have sufficient clearance.
During sudden driving or braking maneuvers,
the objects could get caught between the
pedals. You could then no longer brake or
accelerate. This could lead to accidents and
injury.
Rolling with the engine switched offGWARNING
There is no power assistance for the steering
and the brake when the engine is not running.
Steering and braking requires significantly
more effort and you could lose control of the
vehicle and cause an accident as a result.
Do not turn off the engine while the vehicle is
in motion.
Exhaust check
GWARNING
Inhalation of exhaust gas is hazardous to your
health. All exhaust gas contains carbon
monoxide (CO), and inhaling it can cause
unconsciousness and possible death.
Do not run the engine in confined areas (such
as a garage) which are not properly ventilated.
If you think that exhaust gas fumes are
entering the vehicle while driving, have the
cause determined and corrected
immediately. If you must drive under these
conditions, drive only with at least one
window fully open at all times.
Certain engine systems are designed to keep
the level of poisonous components in exhaust
fumes within legal limits.
These systems only work at peak efficiency
when they are maintained exactly in
accordance with the manufacturer's
specifications. For this reason, all work on the
engine must be carried out only by qualified
and authorized Mercedes-Benz technicians.
The engine settings must not be changed in
any circumstances. Furthermore, all specific
service work must be carried out at regular
intervals and in accordance with the
170Driving tipsDriving and parking

Mercedes-Benz service requirements. Details
can be found in the Service Booklet.
Engine oil
! Vehicles with a diesel particle filter:
If the vehicle is mostly driven for short
distances, it is possible that malfunctions
may occur during the automatic cleaning of
the diesel particle filter. This can lead to
engine damage. Therefore, if you frequently
drive short distances, make sure to drive
on highways or inter-urban roads for 20
minutes at least every 310 miles (500 km).
Brakes
Important safety notes
GWARNING
On slippery road surfaces, never downshift in
order to obtain braking action. This could
result in drive wheel slip and reduced vehicle
control. Your vehicle's ABS will not prevent
this type of loss of control.
GWARNING
Make sure that you do not endanger other
road users when you apply the brakes.
Downhill gradients
! On long and steep gradients, you must
reduce the load on the brakes by shifting
early to a lower gear. This allows you to take
advantage of the engine braking effect and
helps avoid overheating and excessive
wear of the brakes.
When you take advantage of the engine
braking effect, a drive wheel may not turn
for some time, e.g. on a slippery road
surface. This could cause damage to the
drive train. This type of damage is not
covered by the Mercedes-Benz warranty.
Heavy and light loadsGWARNING
Depressing the brake pedal constantly results
in excessive and premature wear to the brake
pads.
It may also cause the brakes to overheat,
seriously impairing their effectiveness. It may
then not be possible to stop the vehicle in
sufficient time to avoid an accident.
If the brakes have been subjected to a heavy
load, do not stop the vehicle immediately, but
drive on for a short while. This allows the
airflow to cool the brakes more quickly.
Wet roads
GWARNING
After driving in heavy rain for some time
without applying the brakes or through water
deep enough to wet brake components, the
first braking action may be somewhat
reduced. You have to depress the brake pedal
more firmly. Maintain a safe distance from
vehicles in front.
After driving on a wet road or having the
vehicle washed, brake firmly while paying
attention to the traffic conditions. This will
warm up the brake discs, thereby drying them
more quickly and protecting them against
corrosion.
Limited braking performance on salt
treated roads
GWARNING
The layer of salt on the brake discs and the
brake pads/linings may cause a delay in the
braking effect, resulting in a significantly
longer braking distance, which could lead to
an accident.
To avoid this danger, you should:
R occasionally brake carefully, without
putting other road users at risk, when you
are driving on salted roads. This helps to
Driving tips171Driving and parkingZ

remove any salt that may have started to
build up on the brake discs and the brake
pads/linings.
R maintain a greater distance to the vehicle
ahead and drive with particular care.
R carefully apply the brakes at the end of a
trip and immediately after commencing a
new trip, so that salt residues are removed
from the brake discs.
Servicing the brakes
! If the red brake warning lamp lights up in
the instrument cluster and you hear a
warning tone while the engine is running,
the brake fluid level may be too low.
Observe additional warning messages in
the multifunction display.
The brake fluid level may be too low due to
brake pad wear or leaking brake lines.
Have the brake system checked
immediately. This work should be carried
out at an authorized Mercedes-Benz
Center.
All checks and maintenance work on the
brake system must be carried out at a
qualified specialist workshop. This work
should be carried out at an authorized
Mercedes-Benz Center.
Have the brake pads replaced and the brake
fluid renewed at a qualified specialist
workshop, e.g. an authorized Mercedes-Benz
Center.
GWARNING
If brake pads or brake fluid other than those
recommended are used, the braking
properties of the vehicle can be degraded to
an extent that safe braking is substantially
impaired. This could result in an accident.
! Vehicles with 4MATIC: function or
performance tests may only be carried out
on a 2-axle dynamometer. If you are
planning to have the vehicle tested on such
a dynamometer, contact an authorized
Mercedes-Benz Center to obtain further
information first. Otherwise, you could
damage the drive train or the brake system.
! Vehicles with 4MATIC: as the ESP®
system operates automatically, the engine
and the ignition must be switched off
(SmartKey in position 0 or 1 in the ignition
lock or Start/Stop button in position 0 or
1 ) while the parking brake is being tested
on a brake dynamometer.
Braking maneuvers triggered automatically
by ESP ®
may seriously damage the brake
system.
! Vehicles with 4MATIC: as the ESP®
system operates automatically, the engine
and the ignition system must be switched
off (SmartKey in position 0 or 1 in the
ignition lock or Start/Stop button in
position 0 or 1) when:
R testing the parking brake on a brake
dynamometer.
R you intend to have the vehicle towed with
one of the axles raised.
Braking maneuvers triggered automatically
by ESP ®
may seriously damage the brake
system.
If your brake system is subject only to
moderate loads, you should test the
functionality of your brakes at regular
intervals by pressing firmly on the brake pedal
at high speeds. This improves the grip of the
brake pads.GWARNING
Make sure that you do not endanger other
road users when you apply the brakes.
You can find a description of Brake Assist
(BAS) on ( Y page 64) or of BAS PLUS on
( Y page 64).
172Driving tipsDriving and parking

AMG high-performance and ceramic
brakesGWARNING
New vehicle brake pads and discs, and
replacement brake pads and discs may take
several hundred miles of driving until they
provide optimum braking efficiency. Until that
time, you may need to use increased brake
pedal pressure while braking. Please be aware
of this and adjust your driving and braking
accordingly during this break-in period.
Excessive high-demand braking will cause
correspondingly high brake wear. Please be
attentive to the brake warning lamp in the
instrument cluster and brake condition
messages in the multifunction display.
Especially for high performance driving, it is
important to maintain and have the brake
system checked regularly.
The AMG brake systems are designed for
heavy loads. This may lead to noise when
braking. This will depend on:
R speed
R braking force
R environmental conditions, such as
temperature and humidity
The wear of individual components of the
brake system, such as the brake pads/linings
or brake discs, depends on the individual
driving style and operating conditions.
For this reason, it is impossible to state a
mileage that will be valid under all
circumstances. An aggressive driving style
will lead to high wear. You can obtain further
information about this from your authorized
Mercedes-Benz Center.
Driving on wet roads
Hydroplaning
If water has accumulated to a certain depth
on the road surface, there is a danger of
hydroplaning occurring, even if:
R you drive at low speeds.
R the tires have adequate tread depth.
For this reason, in the event of heavy rain or
in conditions in which hydroplaning can occur
you must drive in the following manner:
R reduce your speed
R avoid ruts
R brake carefully
Driving on flooded roads
! Do not drive through flooded areas.
Check the depth of any water before driving
through it. Drive slowly through standing
water. Otherwise, water may enter the
vehicle interior or the engine compartment.
This can damage the electronic
components in the engine or the automatic
transmission. Water can also be drawn in
by the engine's air suction nozzles and this
can cause engine damage.
Winter driving
Important safety notes
GWARNING
If the vehicle becomes trapped in snow,
ensure that snow is kept away from the
exhaust pipe and from around the vehicle as
long as the engine is running. Otherwise,
poisonous carbon monoxide (CO) may enter
the vehicle, resulting in loss of consciousness
and even death.
To assure sufficient fresh air ventilation, open
a window slightly on the side of the vehicle
not facing the wind.
At the onset of winter, have your vehicle
winterproofed at a qualified specialist
Driving tips173Driving and parkingZ

workshop, e.g. at an authorized Mercedes-
Benz Center.
i Vehicles with a diesel engine: do not
cover the radiator, e.g. with a protective
cover. The measuring function of the
Onboard Diagnosis System may otherwise
provide inaccurate values. Some of these
values are required by law and must
therefore always be accurate.
Winter tires
At temperatures below 45 ‡(+7 †), use
winter tires or all-season tires. Both types of
tire are identified by the M+S marking.
Only winter tires bearing the i snowflake
symbol in addition to the M+S marking
provide the best possible grip in wintry road
conditions. Only these tires will allow driving
safety systems such as ABS and ESP ®
to
function optimally in winter, as these tires
have been designed specifically for driving on
snow.
Use M+S tires of the same make and tread on
all wheels to maintain safe handling
characteristics.
GWARNING
M+S tires with a tread depth of less than 1
/ 6
inch (4 mm) must be replaced immediately.
They are no longer suitable for use in winter.
Always observe the maximum permissible
speed specified for the M+S tires you have
mounted.
Once you have mounted the winter tires:
XCheck the tire pressures ( Y page 353).XRestart the tire pressure monitor
( Y page 355).GWARNING
If you use your spare wheel when M+S tires
are mounted on the other wheels, be aware
that the difference in tire characteristics
impairs cornering ability and reduces driving
stability. Adapt your driving style accordingly.
Have the spare wheel replaced by a normal
wheel with an M+S tire at the nearest
Mercedes-Benz Center.
Snow chains
For safety reasons, Mercedes-Benz
recommends that you only use snow chains
which have been specially approved for your
vehicle by Mercedes-Benz, or are of a
corresponding standard of quality.
! On vehicles with AIRMATIC, you must
drive at raised vehicle level if snow chains
have been mounted. The vehicle may
otherwise be damaged.
! There is not enough space for snow
chains on some wheel sizes. Observe the
information under "Tires and wheels" in the
"Technical Data" section to avoid damage
to the vehicle or the wheels.
R Only use snow chains when driving on
roads completely covered by snow. Do not
exceed the maximum permissible speed of
30 mph (50 km/h). Remove the snow
chains as soon as possible when you are no
longer driving on snow-covered roads.
R Local regulations may restrict the use of
snow chains. Applicable regulations must
be observed if you wish to mount snow
chains.
R Snow chains must not be mounted on
emergency spare wheels.
If you intend to mount snow chains, please
bear the following points in mind:
R you may not attach snow chains to all
wheel-tire combinations; see the
information under "Wheel and tire
combinations" in the "Wheels and tires"
section.
R mount snow chains only in pairs and only
to the rear wheels. Observe the
manufacturer's installation instructions.
! If snow chains are mounted on the front
wheels, the snow chains could grind
against the bodywork or components of the
174Driving tipsDriving and parking

chassis. This could result in damage to the
vehicle or the tires.
! Vehicles with steel wheels: if you wish
to mount snow chains on steel wheels,
make sure that you remove the respective
wheels' hubcaps first. The hubcaps may
otherwise be damaged.
i You may wish to deactivate
ESP ®
(Y page 66) when pulling away with
snow chains mounted. This way you can
allow the wheels to spin in a controlled
manner, achieving an increased driving
force (cutting action).
Slippery road surfacesGWARNING
The outside temperature indicator is not
designed to serve as an ice-warning device
and is therefore unsuitable for that purpose.
Indicated temperatures just above the
freezing point do not guarantee that the road
surface is free of ice. The road may still be icy,
especially in wooded areas or on bridges.
GWARNING
On slippery road surfaces, never downshift in
order to obtain braking action. This could
result in drive wheel slip and reduced vehicle
control. Your vehicle's ABS will not prevent
this type of loss of control.
Drive particularly carefully on slippery road
surfaces. Avoid sudden acceleration, steering
and braking maneuvers. Do not use cruise
control or DISTRONIC PLUS.
If the vehicle threatens to skid or cannot be
stopped when moving at low speed:
XShift the transmission to position N.
i
For more information on driving with
snow chains, see ( Y page 174).
GWARNING
Make sure that you do not endanger other
road users when you apply the brakes.
Driving systems
Cruise control
Important safety notes
Cruise control maintains a constant road
speed for you. It brakes automatically in order
to avoid exceeding the set speed. On long and
steep downhill gradients, especially if the
vehicle is laden, you must select shift range
1 , 2 or 3 in good time. By doing so, you will
make use of the braking effect of the engine,
which relieves the load on the brake system
and prevents the brakes from overheating
and wearing too quickly.
Use cruise control only if road and traffic
conditions make it appropriate to maintain a
steady speed for a prolonged period. You can
set any road speed above 20 mph
(30 km/h).
GWARNING
The cruise control is a convenience system
designed to assist the driver during vehicle
operation. The driver is and must always
remain responsible for the vehicle's speed
and for safe brake operation.
Only use the cruise control if the road, traffic,
and weather conditions make it advisable to
travel at a constant speed.
R The use of the cruise control can be
dangerous on winding roads or in heavy
traffic because conditions do not allow safe
driving at a constant speed.
R The use of the cruise control can be
dangerous on slippery roads. Rapid
changes in tire traction can result in wheel
spin and loss of control.
R Deactivate the cruise control when driving
in fog.
The "Resume" function should only be
operated if the driver is fully aware of the
previously set speed and wishes to resume
this particular preset speed.
Driving systems175Driving and parkingZ

overtake, cruise control adjusts the
vehicle's speed to the last speed stored
after you have finished overtaking.
Making adjustments in 1 mph (Canada:
1 km/h) incrementsXBriefly press the cruise control lever to the
pressure point, up : for a higher speed or
down ; for a lower speed.
The last speed stored is increased or
reduced.
Making adjustments in 5 mph (Canada:
10 km/h) increments
XBriefly press the cruise control lever
beyond the pressure point, up : for a
higher speed or down ; for a lower speed.
The last speed stored is increased or
reduced.
Deactivating cruise control
There are several ways to deactivate cruise
control:
XBriefly press the cruise control lever
forwards =.
or
XBrake.
Cruise control is automatically deactivated if:
R you depress the parking brake.
R you are driving below 20 mph (30 km/h).
R ESP ®
intervenes or you deactivate ESP ®
.
R you shift the transmission to position N
while driving.
If cruise control is deactivated, you will hear
a warning tone. You will see the Cruise
Control Off message in the multifunction
display for approximately five seconds.
i The last speed stored is cleared when you
switch off the engine.
DISTRONIC PLUS
Important safety notes
DISTRONIC PLUS regulates the speed and
automatically helps you maintain the
distance to the vehicle detected in front. It
brakes automatically in order to avoid
exceeding the set speed.
On long and steep downhill gradients,
especially if the vehicle is laden, you must
select shift range 1, 2 or 3 in good time. By
doing so, you will make use of the braking
effect of the engine, which relieves the load
on the brake system and prevents the brakes
from overheating and wearing too quickly.
If a slower-moving vehicle is detected in front,
DISTRONIC PLUS causes your vehicle to
brake and maintain a preset distance to the
vehicle in front.
GWARNING
The DISTRONIC PLUS requires familiarity with
its operational characteristics. We strongly
recommend that you review the following
information carefully before operating the
system.
GWARNING
The DISTRONIC PLUS is a convenience
system. Its speed adjustment reduction
capability is intended to make cruise control
more effective and usable when traffic speeds
vary. It is not however, intended to, nor does
it, replace the need for extreme care.
The responsibility for the vehicle's speed,
distance to the preceding vehicle and, most
importantly, brake operation to ensure a safe
stopping distance, always remains with the
driver.
The DISTRONIC PLUS cannot take street and
traffic conditions into account.
Complex driving situations are not always
fully recognized by the DISTRONIC PLUS. This
could result in wrong or missing distance
warnings.
Driving systems177Driving and parkingZ