2008 MERCEDES-BENZ C300 Key go

322 Operation
At the gas station
Refueling
The fuel filler flap is located on the
right-hand side of the vehicle towards the
rear. Locking and unlocking the vehicle
with the SmartKey or the SmartKey with
KEYLESS-GO* (Canada only) automatically
locks and unlocks the fuel filler flap.1To open fuel filler flap
2To insert fuel filler cap
3Holder
Warning!G
Gasoline is highly flammable and poisonous.
It burns violently and can cause serious per-
sonal injury.
Never allow sparks, flame or smoking mate-
rials near gasoline!
Turn off the engine before refueling.
Whenever you are around gasoline, avoid in-
haling fumes and any skin or clothing con-
tact. Extinguish all smoking materials.
Direct skin contact with fuels and the inha-
lation of fuel vapors can damage your
health.
Warning!G
C 300/C 300 4MATIC/C 300 4MATIC Sport
and 300 Sport (with automatic transmis-
sion*):
Flexible Fuel Vehicles (identified by a label
reading Premium gasoline or E85 only! on
fuel filler flap):
Ethanol fuel (E85) and its vapors are highly
flammable, poisonous and burn easily. Etha-
nol fuel can cause serious injuries if ignited
or if you come into contact with it or inhale
fumes of it. Avoid inhalation of ethanol
fumes and skin contact with ethanol. Extin-
guish all open flames before refueling. Never
smoke or create sparks close to ethanol.
iIn case that the central locking system does
not release the fuel filler flap, or the opening
mechanism is clamping, notify Roadside Assis-
tance or an authorized Mercedes-Benz Center.
iOnly use premium unleaded gasoline with a
minimum Posted Octane Rating of 91 (average
of 96 RON / 86 MON). Information on gasoline
quality can normally be found on the fuel pump.
C 300/C 300 4MATIC/C 300 4MATIC Sport and
300 Sport (with automatic transmission*):
Flexible Fuel Vehicles are identified by a label
reading Premium gasoline or E85 only! on the
fuel filler flap.

323 Operation
At the gas station
Turn off the engine.
Vehicles with automatic transmission*:
Move the gear selector lever to
positionP (
page 140).
Remove the SmartKey from the starter
switch.
Vehicles with SmartKey with
KEYLESS-GO*:
Turn off the engine by pressing the
KEYLESS-GO* button once.
Open the driver’s door (this puts
the starter switch in position0,
same as with the SmartKey re-
moved from the starter switch). The
driver’s door then can be closed
again.
Open the fuel filler flap by pushing at
the point indicated by arrow 1.The fuel filler flap springs open.
Turn the fuel cap counterclockwise and
hold on to it until possible pressure is
released.
Take off the fuel filler cap and set it in
the direction of arrow 2 and place it
into holder 4 located on the inside of
the fuel filler flap.
To prevent fuel vapors from escaping
into open air, fully insert filler nozzle
unit.
Only fill your tank until the filler nozzle
unit cuts out – do not top off or over-
fill.
Replace the fuel cap by turning it clock-
wise until it audibly engages.
Close the fuel filler flap.
You should hear the latch close shut.
For more information on gasoline or E85, see
“Premium unleaded gasoline” (
page 481) or
the Factory Approved Service Products
pamphlet (USA only) in your vehicle literature
portfolio, or contact an authorized
Mercedes-Benz Center.
Warning!G
Overfilling of the fuel tank may create pres-
sure in the system which could cause a gas
discharge. This could cause the gas to spray
back out when removing the fuel pump noz-
zle, which could cause personal injury.
iMake sure to close the fuel filler flap before
locking your vehicle as the flap locking pin pre-
vents closing after you have locked the vehicle.
iLeaving the engine running and the fuel cap
open can cause the yellow engine malfunction
indicator lamp ± to illuminate.
For more information, see the “Practical hints”
section (
page 378).

365 Operation
Vehicle care
of incompatibility between materials used
in the production process and others ap-
plied later.
We have selected car-care products and
compiled recommendations which are
specially matched to our vehicles and
which always reflect the latest technology.
You can obtain Mercedes-Benz approved
car-care products at an authorized
Mercedes-Benz Center.
Scratches, corrosive deposits, corrosion or
damage due to negligent or incorrect care
cannot always be removed or repaired with
the car-care products recommended here.
In such cases it is best to seek aid at an au-
thorized Mercedes-Benz Center.
The following topics deal with the cleaning
and care of your vehicle and give important
“how-to” information as well as references
to Mercedes-Benz approved car-care
products.Power washer
Tar stains
Quickly remove tar stains before they dry
and become more difficult to remove. A tar
remover is recommended.Paintwork, painted body components
Mercedes-Benz approved Paint Care
should be applied when water drops on the
paint surface do not “bead up”. This should
normally be done every 3 to 5 months, de-
pending on the climate and washing deter-
gent used.
Mercedes-Benz approved Paint Cleaner
should be applied if the paint surface
shows signs of embedded dirt (i.e. loss of
gloss).
Do not apply any of these products or wax
if your vehicle is parked in the sun or if the
hood is still hot.
Use the appropriate MB-Touch-Up
Stick for quick and provisional repairs
of minor paint damage (i.e. chips from
stones, vehicle doors, etc.).
!Follow the instructions provided by the pow-
er washer manufacturer on maintaining a dis-
tance between the vehicle and the nozzle of the
power washer.
Never use a round nozzle to power-wash tires.
The intense jet of water can result in damage to
the tire.
Always replace a damaged tire.
Always keep the jet of water moving across the
surface. Do not aim directly at electrical parts,
electrical connectors, seals, or other rubber
parts.
iVehicles with KEYLESS-GO*:
If a door handle is hit by a strong jet of water, and
a SmartKey with KEYLESS-GO* is in close prox-
imity, i.e. within approximately 3 ft (approxi-
mately 1 m), the vehicle could be inadvertently
locked or unlocked.
!Affixing stickers, magnets, adhesive tape or
similar materials to painted body components
may damage the paintwork.

366 Operation
Vehicle care
Engine cleaning
Prior to cleaning the engine compartment,
make sure to protect electrical compo-
nents and connectors from contact with
water and cleaning agents.
Corrosion protection, such as
MB Anticorrosion Wax, should be applied
to the engine compartment after every
engine cleaning. Before applying, all
control linkage bushings and joints should
be lubricated. The poly-V-belt and all pul-
leys should be protected from any wax. Vehicle washing
In the winter, thoroughly remove all traces
of road salt as soon as possible.
When washing the vehicle underbody, do
not forget to clean the inner sides of the
wheels.Hand-wash
Do not use hot water or wash your vehicle
in direct sunlight.
Only use a mild car wash detergent,
such as Mercedes-Benz approved Car
Shampoo.
Thoroughly spray the vehicle with a dif-
fused jet of water.
Direct only a very weak spray towards
the ventilation intake.
Use plenty of water and rinse the
sponge and chamois frequently.
Rinse with clean water and thoroughly
dry with a chamois.
Do not allow cleaning agents to dry on
the finish.
iVehicles with KEYLESS-GO* (Canada only):
If a door handle is hit by a strong jet of water, and
a SmartKey with KEYLESS-GO* is in close prox-
imity, i.e. within approximately 3 ft (approxi-
mately 1 m), the vehicle could be inadvertently
locked or unlocked.
!Do not use scouring agents on these parts.
Never apply strong force and only use a soft,
non-scratching cloth when cleaning the vehicle.
Do not attempt to wipe the surface with a dry
cloth or sponge.
Otherwise you may scratch or damage the paint.

368 Operation
Vehicle care
Cleaning the windows and the wiper
blades
Make sure the hood is fully closed.
Placing wiper arms in vertical position
Vehicles with SmartKey:
Turn SmartKey in starter switch
position1.
Turn combination switch to wiper
settingu (
page 117).
With wiper arm in vertical position, turn
the SmartKey in starter switch to
position0.Vehicles with KEYLESS-GO*
(Canada only):
Make sure the vehicle’s on-board elec-
tronics have status 1 (
page 84).
Turn combination switch to wiper
settingu (
page 117).
Press KEYLESS-GO start/stop button
repeatedly until windshield wipers
start.
Press KEYLESS-GO start/stop button
when the wiper arms are in a vertical
position.Cleaning
Fold the wiper arms forward until they
snap into place.
Clean the wiper blade inserts with a
clean cloth and detergent solution.
Use a soft, clean cloth and a mild win-
dow cleaning solution on all outside
and inside glass surfaces.
An automotive glass cleaner is recom-
mended.
!The windshield wipers must be in a vertical
position before folding them away from the wind-
shield. They could otherwise damage the hood.
Never open the hood when the wiper arms are
folded forward.Warning!G
For safety reasons, switch off wipers and re-
move SmartKey from starter switch (vehi-
cles with KEYLESS-GO* (Canada only):
Make sure the vehicle’s on-board electron-
ics have status0) before cleaning the wind-
shield and/or the wiper blades. Otherwise,
the wiper motor could suddenly turn on and
cause injury.
!Do not pull on the wiper blade inserts. They
could tear.

369 Operation
Vehicle care
Cleaning the panorama roof with
tilt/sliding panel*
The rear part of the tilt/sliding panel has a
protective layer on the inside.
Use a soft, clean cloth and a mild
window cleaning solution.
An automotive glass cleaner is recom-
mended.Chrome-plated exhaust tip*
Regular cleaning and care of chrome-plat-
ed exhaust tips will help to maintain their
shine and the classy appearance.Use Mercedes-Benz approved Chrome
Polishing Paste each time the vehicle
has been washed, especially during the
winter.
!Fold the windshield wiper arms back onto
the windshield before turning the SmartKey in
the starter switch or pressing the KEYLESS-GO*
start/stop button (vehicles with KEYLESS-GO*
(Canada only)).
Hold on to the wiper when folding the wiper arm
back. If released, the force of the impact from
the tensioning spring could crack the windshield.
!To clean the window interior, do not use a
dry cloth, abrasives, solvents or cleaners con-
taining solvents. Do not touch the inside of the
front, rear or side windows with hard objects
such as an ice scraper or ring. Doing so may
damage the windows.
!Do not use a dry cloth, abrasives, solvents
or cleaners containing solvents. Do not touch
the protective layer with hard objects such as an
ice scraper or ring. Never apply strong force and
only use a soft, non-scratching cloth when clean-
ing the rear part of the tilt/sliding panel.
Otherwise you may scratch or damage the pro-
tective layer.!Do not use alkaline cleaners such as wheel
cleaners as they could cause corrosion.

373 Practical hints
What to do if …?
Where will I find ...?
Unlocking/locking in an emergency
Resetting activated head restraints
Replacing SmartKey batteries
Replacing bulbs
Replacing wiper blades
Flat tire
Battery
Jump starting
Towing the vehicle
Fuses

392 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Shift
to PYou have turned off the engine with the
KEYLESS-GO* start/stop button (Canada only) in
gear selector lever positionN and opened the driv-
er’s door.
or
You have attempted to switch off the engine with the
KEYLESS-GO* start/stop button (Canada only) while
the gear selector lever was in positionR orD.Place the gear selector lever in positionP.
Shift to P or N
To Start EngineYou have attempted to start the engine while the au-
tomatic transmission* was set to position R or D.Move the gear selector lever to position P or N
(
page 140).
Tire Press. Monitor
Inoperative
(USA only)
The TPMS is malfunctioning.Have the TPMS checked at an authorized
Mercedes-Benz Center.
Wheel Sensors Error
Tire Pressure Monitor
Inoperative
(USA only)
There are wheels without appropriate wheel sensors
mounted (e.g. winter tires).Have the TPMS checked at an authorized
Mercedes-Benz Center.
Have the wheel sensors installed at an autho-
rized Mercedes-Benz Center.
Tire Press. Monitor
Currently Unavailable
(USA only)
The TPMS is unable to monitor the tire pressure due
to a nearby radio interference source.As soon as the causes of the malfunction have
been removed, the TPMS automatically be-
comes active again after a few minutes driving.