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 G
WARNING
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. G
WARNING
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
Ò11 †, 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, Refueling
321
Driving and parking Z
Checking the tire pressures
Important safety notes G
WARNING
Follow recommended tire inflation pressures.
Do not underinflate tires. Underinflated tires
wear excessively and/or unevenly, adversely
affect handling and fuel economy, and are
more likely to fail from being overheated.
Do
not overinflate tires. Overinflated tires can
adversely affect handling and ride comfort,
wear unevenly, increase stopping distance,
and result in sudden deflation (blowout)
because they are more likely to become
punctured or damaged by road debris,
potholes etc.
Do not overload the tires by exceeding the
specified load limit as indicated on the Tire
and Loading Information placard on the
driver's door B-pillar. Overloading the tires
can overheat them, possibly causing a
blowout. Overloading the tires can also result
in handling or steering problems, or brake
failure.
Check the tire pressure at least once a month.
Only check and correct tire pressures when
the tires are cold ( Y page 493).
Checking tire pressure manually To determine and set the correct tire
pressure, proceed as follows:
X
Remove the valve cap of the tire that is to
be checked.
X Press the tire pressure gauge securely onto
the valve.
X Read 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.
X If necessary, increase the tire pressure to
the recommended value ( Y page 493).
X If 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.
X Screw the valve cap onto the valve.
X Repeat these steps for the other tires. Tire pressure monitor
Important safety notes 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 when the
pressure drops in one or more of the tires. The
tire pressure monitor only functions if the
correct wheel electronics units are installed
on 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
60 seconds and then remains lit constantly,
the tire pressure monitor is malfunctioning. G
WARNING
Each tire, including the spare (if provided),
should be checked at least once a month
when cold and inflated to the pressure
recommended by the vehicle manufacturer
on the Tire and Loading Information placard
on the driver's door B-pillar or the tire
pressure label on the inside of the fuel filler
flap.
If your vehicle has tires of a different size
than the size indicated on the Tire and Loading
Information placard or the tire pressure label,
you should determine the proper tire pressure
for those tires. Tire pressure
497
Wheels and tires
Z
