2012 MERCEDES-BENZ S-CLASS SEDAN fuel cap release

DEF (BlueTEC vehicles only)
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 level is too low, 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 will then not be possible to restart
the engine. Fill the DEF tank with about 1 gal
(3.8l) of 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).
If the outside temperature is lower than 12 ‡
( Ò 11†) , damage may occur when adding DEF.
If DEF is frozen and there is an active warning
indicator, adding may not be possible. Park
the vehicle in a warmer place, e.g. in a garage,
until DEF has become fluid again. It will then
be possible to add DEF again. Alternatively,
have the DEF tank refilled at a qualified
specialist workshop.
Further information about BlueTEC exhaust
gas aftertreatment and DEF is available at any
authorized Mercedes-Benz Center.
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, small amounts
of ammonia vapor may be released. This
depends in particular upon the age of the DEF.
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. Fill the DEF tank only in well-
ventilated areas.
! Only use DEF in accordance with
ISO 22241. Do not mix any additives with
DEF, and do not dilute DEF with water. This
may destroy the BlueTEC exhaust gas
aftertreatment system.
! 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
Refueling325Driving and parkingZ

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.
! Only screw on the DEF refill bottle hand-
tight. It could otherwise be damaged.
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 the trunk floor up ( Y page 438).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.XPress DEF refill bottle = down.
The DEF tank is filled. This may take up to
one minute.
i To add between service intervals, fill the
DEF tank with approximately 1 gal (3.8 l) of
DEF. 1 gal (3.8 l) of DEF is equivalent to
approximately 2 DEF refill bottles. Then
have the DEF supply checked at a qualified
specialist workshop and completely refilled
if necessary.
XRelease DEF refill bottle =.
Refilling stops when the DEF refill bottle is
no longer pressed down. The DEF refill
bottle can be removed when it has been
only partially emptied.326RefuelingDriving and parking

Checking the tire pressures
Important safety notes
Observe the "Tire pressure information"
section ( Y page 495).
Information on air pressure for the tires on
your vehicle can be found:
R on the vehicle's Tire and Loading
Information placard on the B-pillar
R on the tire pressure label on the fuel filler
flap
R in the "Tire pressure information" section
Checking tire pressures manually
To determine and set the correct tire
pressure, proceed as follows:
XRemove the valve cap of the tire that is to
be checked.XPress the tire pressure gauge securely onto
the valve.XRead the tire pressure and compare it with
the recommended value on the Tire and
Loading Information placard on the
B-pillar on the driver's side of your vehicle.XIf necessary, increase the tire pressure to
the recommended value ( Y page 495).XIf the tire pressure is too high, release air
by pressing down the metal pin in the valve
using the tip of a pen, for example. Then
check the tire pressure again using the tire
pressure gauge.XScrew the valve cap onto the valve.XRepeat these steps for the other tires.
Tire pressure monitor
Important safety notes
It is the driver's responsibility to set the tire
pressure to that recommended for cold tires
which is suitable for the operating situation
( Y page 495). Note that the correct tire
pressure for the current operating situation
must first be taught-in to the tire pressure
monitor. If there is a substantial loss of
pressure, the warning threshold for the
warning message is aligned to the reference
values taught-in. Restart the tire pressure
monitor after adjusting the pressure of the
cold tires ( Y page 501). The current
pressures are saved as new reference values.
As a result, a warning message will appear if
the tire pressure drops significantly.
The tire pressure monitor does not warn you
of an incorrectly set tire pressure. Observe
the notes on the recommended tire pressure
( Y page 495).
The tire pressure monitor is not able to warn
you of a sudden loss of pressure, e.g. if the
tire 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 maneuvers.
If a tire pressure monitor system is installed,
the vehicle's wheels have sensors that
monitor the tire pressures in all four tires. The
tire pressure monitor warns you if the
pressure drops in one or more of the tires. The
tire pressure monitor only functions if the
correct sensors are installed to all wheels.
The tire pressure monitor has a yellow
warning lamp in the instrument cluster for
indicating pressure loss/malfunctions (USA)
or pressure loss (Canada). Whether the
warning lamp flashes or lights up indicates
whether a tire pressure is too low or the tire
pressure monitoring system is
malfunctioning:
R if the warning lamp is lit continuously, the
tire pressure on one or more tires is
significantly too low. The tire pressure
monitor is not malfunctioning.
R USA only: if the warning lamp flashes for
around a minute and then remains lit
constantly, the tire pressure monitor is
malfunctioning.GWARNING
Each tire, including the spare (if provided),
should be checked at least once a month
when cold and inflated to the pressure
Tire pressure499Wheels and tiresZ

engine and could result in the vehicle catching
fire.
! Only use commercially available vehicular
ULTRA-LOW SULFUR DIESEL FUEL (ULSD,
15 ppm maximum sulfur content) that
meets the ASTM D975 standard. If you do
not refuel with ULSD, you may damage the
BlueTEC exhaust gas aftertreatment
system of the vehicle.
! Do not use gasoline to refuel vehicles with
a diesel engine. Do not mix diesel fuel with
gasoline, kerosene or paraffin. This may
otherwise result in damage to the fuel
system and engine.
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.
i For further information, consult a
qualified specialist workshop or on the
Internet at http://www.mbusa.com (USA
only).
Information on refueling ( Y page 321).
Bio-diesel - FAME (fatty acid methyl ester)
Mercedes-Benz USA approves the use of bio-
diesel B5 for all BlueTEC diesel engines. The
concentration of bio-diesel in the ULSD may
not exceed 5 % by volume.
Pure biodiesel and diesel fuel with a higher
percentage of biodiesel, such as B20, can
damage the engine and the fuel system. For
this reason, they are not approved.
For more information, consult the gas station
staff. The bio-diesel B5 label on the gasoline
pump must clearly state that the standard for
ULSD has been fulfilled. If the label is not
clear, do not refuel the vehicle.
Do not refuel your vehicle with fuels unless
they have been approved by Mercedes-Benz.
Information on refueling ( Y page 321).Low outside temperatures
i Diesel fuel with improved cold flow
properties is available during the winter
months. Further information about fuel
properties can be obtained from oil
companies, e.g. at gas stations.
Flow improver
To improve the low-temperature resistance of
diesel fuel, a flow improver can be attached.
The effectiveness of a flow improver is not
guaranteed for every fuel.
Only use flow improvers tested and approved
by Mercedes-Benz. During use, please
observe the information on operation.
Correct dosage and sufficient mixing are
decisive in improving low-temperature
resistance with the flow improver.
Overdosage can potentially even decrease
low-temperature resistance and must
therefore be avoided. Follow the
manufacturer's guidelines on dosage.
Mix the additive into the diesel in good time,
before the flow characteristics of the diesel
become insufficient. Otherwise, malfunctions
can arise through heating the fuel system,
e.g. through parking in a heated garage.
More information about recommended flow
improvers can be obtained from any qualified
specialist workshop.
DEF
Please bear the following in mind
DEF is a non-flammable, non-toxic, colorless,
odorless and water-soluble fluid.
High outside temperatures
GWARNING
If you open the DEF tank cap, small amounts
of ammonia vapor may be released. This
depends in particular upon the age of the DEF.
Service products and filling capacities527Technical dataZ