engine MERCEDES-BENZ S-Class 2012 W221 Repair Manual

Program selector button
General information
The program selector button influences:
R the drive program
R the AIRMATIC ( Y page 343) or ABC
( Y page 345) suspension settings
R the engine management
Program selector button
Program selector button on AMG vehicles
In AMG vehicles, drive program E is called
drive program C.
E Economy
C Controlled
EfficiencyComfortable, economical
drivingS SportSporty driving styleM ManualManual gearshifting
i
For further information on the automatic
drive program, see ( Y page 314).
AMG vehicles: only change from automatic
drive program C or S to manual drive program
M when the vehicle is stationary.XPress program selector button :
repeatedly until the letter for the desired
gearshift program appears in the
multifunction display.
i When the engine is started, the automatic
transmission always switches to automatic
drive program E (drive program C in AMG
vehicles).
Steering wheel paddle shifters
:Left-hand steering wheel paddle shifter;Right-hand steering wheel paddle shifter
You can restrict or derestrict the shift range
by using the steering wheel paddle shifters.
You can change gear yourself by using the
steering wheel paddle shifters in the manual
drive program.
Automatic drive program
Drive program E (drive program C on AMG
vehicles) is characterized by the following:
R the vehicle pulling away more gently in
forward and reverse gears, unless the
accelerator pedal is depressed fully
R increased sensitivity. This improves driving
stability on slippery road surfaces, for
example
R the automatic transmission shifting up
sooner. This results in the vehicle being
314Automatic transmissionDriving and parking

driven at lower engine speeds and the
wheels being less likely to spin
Drive program S is characterized by the
following:
R sporty engine settings
R the vehicle pulling away in first gear
R the automatic transmission shifting up
later
R the fuel consumption possibly being higher
as a result of the later automatic
transmission shift points
Shift ranges
Introduction
When the automatic transmission is in
position D, it is possible to restrict or
derestrict the shift range ( Y page 315).
The shift range selected is shown in the
multifunction display. The automatic
transmission shifts only as far as the selected
gear.
Shift range=You can use the engine's braking
effect.5To use the braking effect of the
engine on downhill gradients and
for driving:
R on steep mountain roads
R in mountainous terrain
R in arduous conditions4To use the braking effect of the
engine on extremely steep downhill
gradients and on long downhill
stretchesRestricting the shift rangeXPull the left-hand steering wheel paddle
shifter.
The automatic transmission shifts down
one gear and restricts the shift range to the
relevant gear.
i If the engine exceeds the maximum
engine speed when shifting down, the
automatic transmission protects against
engine damage by not shifting down.
i If the maximum engine speed for the shift
range is reached and you continue to
accelerate, the automatic transmission
shifts up in order to prevent the engine
from overrevving, even if the shift range is
restricted.
Derestricting the shift range
XPull the right-hand steering wheel paddle
shifter.
The shift range is derestricted.
Clearing the shift range restriction
XPull and hold the right-hand steering wheel
paddle shifter until D is shown again in the
multifunction display.
The automatic transmission shifts from the
current shift range directly to D.
Selecting the ideal shift range
XPull the left-hand steering wheel paddle
shifter and hold it in position.
The automatic transmission shifts to the
gear which allows optimum acceleration
and deceleration. To do this, the automatic
transmission shifts down one or more
gears.Automatic transmission315Driving and parkingZ

Manual drive program
Switching on the manual drive program
The manual drive program is only available for
AMG vehicles.
Manual drive program M is different from
drive program S with regard to spontaneity,
responsiveness and smoothness of gear
changes.
Manual drive program M can be selected
using the program selector button. In manual
drive program M, you can change gear
yourself using the steering wheel paddle
shifters if the transmission is in position D.
The gear currently selected and engaged is
shown in the multifunction display.
XPress the program selector button
( Y page 314) repeatedly until M appears in
the multifunction display.
Upshifting
! In manual drive program M, the automatic
transmission does not shift up
automatically even when the engine
limiting speed for the current gear is
reached. When the engine limiting speed is
reached, the fuel supply is cut to prevent
the engine from overrevving. Always make
sure that the engine speed does not reach
the red area of the tachometer. There is
otherwise a risk of engine damage.
XPull the right-hand steering wheel paddle
shifter ( Y page 314).
The automatic transmission shifts up to the
next gear.
Before the engine speed reaches the red area,
an upshift indicator appears in the
multifunction display.
:Gear indicator;Upshift indicator
Downshifting
XPull the left-hand steering wheel paddle
shifter ( Y page 314).
The automatic transmission shifts down to
the next gear.
i If you brake the vehicle or stop without
shifting down, the automatic transmission
will shift down to a gear that will allow the
vehicle to accelerate or pull away again.
i For maximum acceleration, pull the left-
hand steering wheel paddle shifter until the
transmission selects the optimum gear for
the current speed.
Kickdown
i Kickdown is not possible in manual drive
program M.
Switching off the manual drive program
XPress the program selector button
( Y page 314) repeatedly until C or S
appears in the multifunction display.316Automatic transmissionDriving and parking

Problems with the transmissionProblemPossible causes/consequences and M SolutionsThe transmission has
problems shifting gear.The transmission is losing oil.XHave the transmission checked at a qualified specialist
workshop, e.g. an authorized Mercedes-Benz Center,
immediately.The acceleration ability
is deteriorating.
The transmission no
longer changes gear.The transmission is in emergency mode.
It is only possible to shift into second gear and reverse gear.XStop the vehicle.XShift the transmission to position P.XSwitch off the engine.XWait at least 10 seconds before restarting the engine.XShift the transmission to position D or R.
If D is selected, the transmission shifts into second gear; if R is
selected, the transmission shifts into reverse gear.XHave the transmission checked at a qualified specialist
workshop, e.g. an authorized Mercedes-Benz Center,
immediately.Transfer case
This section is only valid for vehicles with 4-
wheel drive (4MATIC). Power is always
transmitted to both axles.
! Performance tests may only be carried
out on a 2-axle dynamometer. The brake
system or transfer case could otherwise be
damaged. Contact a qualified specialist
workshop for a performance test.
Mercedes-Benz recommends that you use
an authorized Mercedes-Benz Center for
this purpose.
! To prevent ESP ®
from intervening, the
ignition must be switched off (SmartKey or
the Start/Stop button in position 0 or 1) if:
R the electric parking brake is being tested
on a brake dynamometer.
R the vehicle is being towed with only one
axle raised (not permitted for vehicles
with 4MATIC).The brake system could otherwise be
damaged.
Refueling
Important safety notes
GWARNING
Gasoline and diesel fuels are highly flammable
and poisonous. They burn violently and can
cause serious injury.
Never allow sparks, flames or smoking
materials near gasoline or diesel fuel!
Turn off the engine before refueling.
Whenever you are around gasoline or diesel
fuel, avoid inhaling fumes and any skin or
clothing contact. Extinguish all smoking
materials.
Direct skin contact with fuels and the
inhalation of fuel vapors are damaging your
health.
Refueling317Driving and parkingZ

GWARNING
Overfilling of the fuel tank may create
pressure in the system which could cause a
gas discharge. This could cause the gasoline
to spray back out when removing the fuel
pump nozzle, which could cause personal
injury.
GWARNING
Hybrid vehicles: be sure to read the "HYBRID"
supplement. Otherwise, you could fail to
recognize dangers.
GWARNING
Do not fill diesel tanks with gasoline. Do not
mix diesel fuel with gasoline. Otherwise the
fuel system and engine could be damaged. In
addition, the vehicle could catch fire.
! Do not use gasoline to refuel vehicles with
a diesel engine. Do not use diesel to refuel
vehicles with a gasoline engine. Even a
small quantity of the wrong fuel will
damage the fuel system and engine.
! Do not switch on the ignition if you
accidentally refuel with the wrong fuel.
Otherwise, the fuel will enter the fuel lines.
Notify a qualified specialist workshop and
have the fuel tank and fuel lines drained
completely.
Gasoline
Fuel grade
! You should only refuel with unleaded
premium-grade gasoline as this avoids
damaging the catalytic converter.
If engine running problems are apparent,
have the cause checked immediately and
repaired. Excess unburned fuel can
otherwise enter the catalytic converter,
leading to overheating and possibly
causing a fire.
! Use a filter when refueling from a fuel can.
Otherwise, the fuel lines and/or injection
system could be blocked by particles from
the fuel can.
i Only refuel with premium-grade unleaded
gasoline with a specified minimum octane
number of 91 (average value of 96 RON/
86 MON).
You will usually find information about the
fuel grade on the pump. If you cannot find
the label on the pump, ask the staff for
assistance.
You can find more information under "Fuel"
( Y page 525), or by contacting an
authorized Mercedes-Benz Service Center
or visiting http://www.mbusa.com (USA
only).
Diesel
Fuel grade
! Only refuel with ULTRA-LOW SULFUR
DIESEL FUEL (ULSD, 15 ppm SULFUR
MAXIMUM). Using other diesel fuels could
result in increased wear and damage to the
engine and/or exhaust system.
Never refuel with marine diesel or heating
oil.
Do not mix these fuels with diesel fuels and
do not use any special additives, as this
may result in damage.
! Use a filter when adding fuel from a fuel
can. Otherwise, the fuel lines and/or the
fuel injection system could be blocked by
particles from the fuel can.
i Usually, you will find information about
the fuel grade on the pump. If you cannot
find the label on the gasoline pump, ask the
gas station staff.
You can find more information under “Fuel”
( Y page 525), or by contacting an
authorized Mercedes-Benz Service Center
or visiting http://www.mbusa.com (USA
only).
318RefuelingDriving and parking

Low outside temperatures
! Do not use gasoline to refuel vehicles with
a diesel engine. Never mix diesel with
gasoline or kerosene, as this may result in
damage to the engine or fuel system.
Diesel fuel with improved cold flow properties
is available during the winter months. Further
information on fuel properties can be
obtained from oil companies, e.g. at gas
stations.
Refueling
Fuel filler flap
The fuel filler flap is unlocked or locked
automatically when you open or close the
vehicle with the SmartKey or using KEYLESS-
GO.
The position of the fuel filler cap is displayed
in the instrument cluster 8. The arrow
next to the filling pump indicates the side of
the vehicle.
:To open the fuel filler flap;To insert the fuel filler cap=Tire pressure table?Fuel type
Opening
XSwitch off the engine.XRemove the SmartKey from the ignition
lock.KEYLESS-GO: open the driver’s door. This
switches the ignition to position 0, which
corresponds to having removed the
SmartKey. The driver’s door can be closed
again.XPress the fuel filler flap in the direction of
arrow :.
The fuel filler flap opens slightly.XOpen the fuel filler flap.XTurn the fuel filler cap counter-clockwise
and remove it.XInsert the fuel filler cap into the holder
bracket on the inside of filler flap ;.XCompletely insert the pump nozzle into the
filler neck and refuel.XOnly fill the tank until the pump nozzle
switches off.
! Overfilling the fuel tank could damage the
fuel system.
Closing
XReplace the fuel filler cap and turn it
clockwise. The fuel filler cap audibly
engages.XClose the fuel filler flap.
i If you drive with the fuel filler cap open,
the reserve fuel warning lamp flashes. In
addition, the ; Check Engine warning
lamp may light up. A message appears in
the multifunction display ( Y page 407).
For further information on warning and
indicator lamps in the instrument cluster,
see ( Y page 427).
i Close the fuel filler flap before locking the
vehicle. A locking pin otherwise prevents
the fuel filler flap from closing after the
vehicle has been locked.
Refueling319Driving and parkingZ

Problems with fuel and the fuel tankProblemPossible causes/consequences and M SolutionsFuel is leaking from the
vehicle.GRisk of explosion or fire
The fuel line or the fuel tank is defective.
XTurn the SmartKey to position 0(Y page 303) in the ignition lock
immediately and remove it.XDo not restart the engine under any circumstances.XConsult a qualified specialist workshop.The fuel filler flap
cannot be opened.The fuel filler flap is not unlocked.
or
The SmartKey battery is discharged.XUnlock the vehicle ( Y page 78).
or
XUnlock the vehicle using the mechanical key ( Y page 81).The fuel filler flap is unlocked, but the opening mechanism is
jammed.XConsult a qualified specialist workshop.The engine will not
start.The fuel tank of a vehicle with a diesel engine has been run
completely dry.XRefuel the vehicle with at least 5.3 US qt (5 liters) of diesel.XTurn the ignition on for at least 10 seconds ( Y page 303).XStart the engine continuously for up to 10 seconds until it runs
smoothly.
orXStart the engine via the touch-start function. To do this, turn the
SmartKey to position 3 (Y page 303) in the ignition lock and
then release it immediately.
If the engine does not start:
XTurn the ignition on again for approximately 10 seconds
( Y page 303).XStart the engine again continuously for up to 10 seconds until
it runs smoothly.
orXStart the engine again via the touch-start function.
If the engine does not start after three attempts:
XConsult a qualified specialist workshop.320RefuelingDriving and parking

DEF
Important notes on use
To function properly, BlueTEC exhaust gas
aftertreatment must be operated with the
reducing agent DEF. Adding DEF is one of the
tasks performed during maintenance. Under
normal operating conditions, a tank of DEF
lasts until the next service due date.
When the DEF supply has almost run out, the
Check Additive See Operator's
Manual message is shown in the
multifunction display.
When the DEF supply sinks to a minimum
level, the Remaining Starts: 16 message
is shown in the multifunction display.
When the Remaining Starts: 16 message
is shown in the multifunction display, you can
start the engine 16 more times. If DEF is not
added, it is then not possible to start the
engine again. Fill the DEF tank with about
1 gal (3.8 l) DEF or have the DEF tank refilled
at a qualified specialist workshop.
Use the special DEF refill bottle when filling
between maintenance intervals. Contact an
authorized Mercedes-Benz Center with any
questions or, if necessary, contact Roadside
Assistance ( Y page 29).
Further information about BlueTEC exhaust
gas aftertreatment and DEF is available at any
authorized Mercedes-Benz Center.
Adding DEF
GWARNING
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,
Refueling321Driving and parkingZ

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 527).
The filler neck for DEF is located under the
"Minispare" emergency spare wheel in the
trunk floor.XSwitch off the ignition.XOpen the trunk.XLift up the trunk floor ( Y page 436).XTurn the "Minispare" emergency spare
wheel fastening in the direction of the
arrow and remove it.XRemove the "Minispare" emergency spare
wheel.XTurn DEF cap : counter-clockwise and
remove it.XTurn DEF filler cap ; counter-clockwise
and open it.
Filler cap ; is secured with a plastic strap.XUnscrew the covering cap from DEF refill
bottle =.XPlace DEF refill bottle = on the filler neck
as shown and screw on clockwise hand-
tight.
! Only screw on the DEF refill bottle hand-
tight. It could otherwise be damaged.
322RefuelingDriving and parking

XPress DEF refill bottle = down.
The DEF tank is filled. This may take up to
one minute.
i If the DEF refill bottle is no longer pressed
down, the filling process stops and the
partially emptied bottle can be removed.
XRelease DEF refill bottle =.XTurn DEF refill bottle = counter-clockwise
and remove it.XPlace DEF filler cap ; on the filler neck and
turn it clockwise.XInsert DEF cap : as shown and turn it
clockwise as far as it will go.XPlace the "Minispare" emergency spare
wheel in the emergency spare wheel well
above the DEF tank.XInsert the "Minispare" emergency spare
wheel fastening and tighten clockwise.XFold the trunk floor down.XClose the trunk lid.XDrive at a speed above 10 mph (16 km/h).
The Check Additive See Operator's
Manual message goes out after
approximately one minute.
i If the Check Additive See
Operator's Manual message remains
shown in the multifunction display, add an
additional bottle of DEF.
i Then, have the DEF supply checked at a
qualified specialist workshop and
completely refilled if necessary.
Parking
Important safety notes
GWARNING
Do not park this vehicle in areas where
combustible materials can come into contact
with the hot exhaust system. Combustible
materials, such as grass, hay or leaves could
be ignited by the hot exhaust system and
cause a vehicle fire. Do not park the vehicle
on dry grassland or harvested grain fields.
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 electric parking brake.
R shift the automatic transmission into 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.
Parking323Driving and parkingZ