2004 MERCEDES-BENZ C CLASS COUPE service

224 OperationDriving instructionsBrakesTo help prevent brake disk corrosion after
driving on wet road surfaces (particularly
salted roads), it is advisable to brake the
vehicle with considerable force prior to
parking. The heat generated serves to dry
the brakes.
If your brake system is normally only sub-
jected to moderate loads, you should occa-
sionally test the effectiveness of the
brakes by applying above-normal braking
pressure at higher speeds. This will also
enhance the grip of the brake pads. If the parking brake is released and the
brake warning lamp in the instrument clus-
ter stays on, the brake fluid level in the res-
ervoir is too low.
Brake pad wear or a leak in the system may
be the reason for low brake fluid in the res-
ervoir.
Have the brake system inspected by quali-
fied technicians immediately. Contact your
authorized Mercedes-Benz Center.
All checks and service work on the brake
system should be carried out by qualified
technicians only. Contact your authorized
Mercedes-Benz Center.
Install only brake pads and brake fluid rec-
ommended by Mercedes-Benz.Warning!
G
After driving in heavy rain for some time
without applying the brakes or through wa-
ter deep enough to wet brake components,
the first braking action may be somewhat
reduced and increased pedal pressure may
be necessary to obtain expected braking ef-
fect. Maintain a safe distance from vehicles
in front.
Resting your foot on the brake pedal will
cause excessive and premature wear of the
brake pads.
It can also result in the brakes overheating,
thereby significantly reducing their effec-
tiveness. It may not be possible to stop the
vehicle in sufficient time to avoid an acci-
dent.
!Be very careful not to endanger other
road users when you apply the brakes.
Refer to the description of the Brake
Assist System (BAS), (
page 74).

230 OperationDriving instructionsPassenger compartmentDriving abroad
Abroad, there is an extensive
Mercedes-Benz service network at your
disposal. If you plan to drive into areas
which are not listed in the index of your
Mercedes-Benz Center directory, you
should request pertinent information from
your authorized Mercedes-Benz Center.Control and operation of radio trans-
mitter
COMAND*, radio and telephone*
Telephones and two-way radios
Radio transmitters, such as a portable tele-
phone or a citizens band unit should only
be used inside the vehicle if they are con-
nected to an antenna that is installed on
the outside of the vehicle.
Refer to the radio transmitter operation in-
structions regarding use of an external
antenna.
Warning!
G
Always fasten items being carried as secure-
ly as possible.
In an accident, during hard braking or sud-
den maneuvers, loose items will be thrown
around inside the vehicle, and cause injury
to vehicle occupants unless the items are
securely fastened in the vehicle.
The trunk is the preferred place to carry ob-
jects.
Warning!
G
Please do not forget that your primary re-
sponsibility is to drive the vehicle safely.
Only operate the COMAND (Cockpit Man-
agement and Data System), radio or tele-
phone
1 if road, weather and traffic
conditions permit.
Bear in mind that at a speed of just 30 mph
(approximately 50 km / h), your vehicle is
covering a distance of approximately
44 feet (approximately 13.5 m) every sec-
ond.
1Observe all legal requirements
Warning!
G
Never operate radio transmitters equipped
with a built-in or attached antenna (i.e. with-
out being connected to an external antenna)
from inside the vehicle while the engine is
running. Doing so could lead to a malfunc-
tion of the vehicle’s electronic system, pos-
sibly resulting in an accident and/or
personal injury.

231
Operation
Driving instructions
Catalytic converter
Your Mercedes-Benz is equipped with
monolithic-type catalytic converters, an
important element in conjunction with the
oxygen sensors to achieve substantial con-
trol of the pollutants in the exhaust emis-
sions. Keep your vehicle in proper
operating condition by following our rec-
ommended maintenance instructions as
outlined in your Service Booklet.
Emission control
Certain systems of the engine serve to
keep the toxic components of the exhaust
gases within permissible limits required by
law.
These systems, of course, will function
properly only when maintained strictly ac-
cording to factory specifications. Any ad-
justments on the engine should, therefore,
be carried out only by qualified
Mercedes-Benz Center authorized techni-
cians. Engine adjustments should not be
altered in any way. Moreover, the specified
service jobs must be carried out regularly
according to Mercedes-Benz servicing re-
quirements. For details refer to the Service
Booklet.
!To prevent damage to the catalytic con-
verters, use only premium unleaded
gasoline in this vehicle.
Any noticeable irregularities in engine
operation should be repaired promptly.
Otherwise, excessive unburned fuel
may reach the catalytic converter,
causing it to overheat and start a fire.
Warning!
G
As with any vehicle, do not idle, park or op-
erate this vehicle in areas where combusti-
ble materials such as grass, hay or leaves
can come into contact with the hot exhaust
system, as these materials could be ignited
and cause a vehicle fire.
Warning!
G
Inhalation of exhaust gas is hazardous to
your health. All exhaust gas contains carbon
monoxide (CO), and inhaling it can cause un-
consciousness and lead to 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 with at least one window
fully open at all times.

234 OperationAt the gas station
Check regularly and before a long trip1 Coolant level
For more information, see “Coolant lev-
el” (
page 241).
2 Brake fluid (fuse box cover removed)
Removing fuse box cover, see “Fuses”
(
page 317).
3 Windshield washer and headlamp
cleaning system*
For more information on filling up the
washer reservoir, see “Windshield
washer system and headlamp cleaning
system” (
page 243).
iUse only 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.
More information on gasoline can be
found in the Factory Approved Service
Products pamphlet.
Flexible Fuel Vehicles are identified by
a label reading Premium gasoline or
E85 only! on the fuel filler flap.
For more information,see “Flexible Fuel
Vehicles” (
page 334).
iLeaving the engine running and the fuel
cap open can cause the ? lamp to
illuminate.
For more information , see“Practical
hints” section (
page 260).


239
Operation
Engine compartment
If you see the message:OBSERVE WAITING PERIOD
If engine is at normal operating
temperature, wait five minutes before
repeating check procedure.

If engine is not yet at normal operating
temperature, wait 30 minutes before
repeating check procedure.
If you see the message:
ENGINE OIL LEVEL
NOT WHEN ENGINE ON!
Turn off the engine.

If the engine is at normal operating
temperature, wait five minutes before
checking oil.

If the engine is not yet at normal
operating temperature, you must wait
30 minutes before checking oil. If there is excess engine oil with the engine
at normal operating temperature, the
following message will appear:
ENGINE OIL LEVEL
REDUCE OIL LEVEL
Have excess oil siphoned or drained
off. Contact your authorized
Mercedes-Benz Center.
For more information on messages in the
display concerning engine oil, see “Practi-
cal hints” (
page 275). Adding engine oil
!Excess oil must be siphoned or drained
off. It could cause damage to the
engine and catalytic converter not
covered by the Mercedes-Benz Limited
Warranty.
!Only use approved engine oils. For a
listing of approved engine oils, refer to
the Factory Approved Service Products
pamphlet in your vehicle literature port-
folio.
In addition, check the oil filler cap for
important information pertaining to the
engine oil needing to meet a specific
Mercedes-Benz specification (e.g. MB
229.5). If such information is printed
on the oil filler cap, only use an engine
oil from the list of approved engine oils
in the Factory Approved Service Prod-
ucts pamphlet that meets the specifi-
cation indicated on the oil filler cap.
Using engine oils of other specification
may cause the FSS to incorrectly deter-
mine the next service interval and will
r e s u l t i n e n g i n e d a m a g e n o t c o v e r e d b y
the Mercedes-Benz Limited Warranty.

242 OperationEngine compartmentBattery
Your vehicle’s battery is located in the en-
gine compartment on the right hand side.
The battery should always be sufficiently
charged in order to achieve its rated ser-
vice life. Refer to Service Booklet for bat-
tery maintenance intervals.
If you use your vehicle mostly for
short-distance trips, you will need to have
the battery charge checked more frequent-
ly.
When replacing the battery, always use
batteries approved by Mercedes-Benz.
If you do not intend to operate your vehicle
for an extended period of time, consult an
authorized Mercedes-Benz Center about
steps you need to observe.Batteries contain materials that can harm
the environment if disposed of improperly.
Recycling of batteries is the preferred
method of disposal. Many states require
sellers of batteries to accept old batteries
for recycling.
G
Observe all safety instructions
and precautions when handling
automotive batteries.
A
Risk of explosion.
D
Keep flames or sparks away
from battery. Do not smoke.
B
Battery acid is caustic. Do not
allow it to come into contact
with skin, eyes or clothing.
In case it does, immediately
flush affected area with clear
water and seek medical help if
necessary.
E
Wear eye protection.
C
Keep children away.
F
Follow the instructions in this
Operator's Manual.

244 OperationTires and wheels
Tires and wheelsSee your authorized Mercedes-Benz Cen-
ter for information on tested and recom-
mended rims and tires for summer and
winter operation. They can also offer ad-
vice concerning tire service and purchase
Retreaded tires are not tested or recom-
mended by Mercedes-Benz, since previous
damage cannot always be recognized on
retreads. Mercedes-Benz can therefore
not assure the operating safety of the vehi-
cle when such tires are used.
See your authorized Mercedes-Benz Cen-
ter for information on tested and recom-
mended rims and tires for summer and
winter operation.
Important guidelines

Use only sets of tires and rims of the
same type and make.


Tires must be of the correct size for the
rim.


Break in new tires for approximately
60 miles (100 km) at moderate
speeds.


Regularly check the tires and rims for
damage. Dented or bent rims can
cause tire pressure loss and damage to
the tire beads


If vehicle is heavily loaded, check tire
pressure and correct as required.


Do not allow your tires to wear down
too far. Adhesion properties on wet
roads are sharply reduced at tread
depths under
1/8in (3 mm).


When replacing individual tires, you
should mount new tires on the front
wheels first (on vehicles with
same-sized wheels all around).
Warning!
G
Replace rims or tires with the same designa-
tion, manufacturer and type as shown on the
original part. See your authorized
Mercedes-Benz Center for further informa-
tion. If incorrectly sized rims and tires are
mounted:

The wheel brakes or suspension compo-
nents can be damaged.


The correct operating clearance of the
wheels and the tires are no longer guar-
anteed.
Warning!
G
Worn, old tires can cause accidents. If the
tire tread is badly worn, or if the tires have
sustained damage, replace them.
When replacing rims, use only genuine
Mercedes-Benz wheel bolts specified for the
particular rim type. Failure to do so can re-
sult in the bolts loosening and possibly an
accident.

245
Operation
Tires and wheels
Life of tire
The service life of a tire is dependent upon
varying factors including but not limited to:

Driving style


Tire pressure


Distance driven
Direction of rotation
Unidirectional tires offer added advantag-
es, such as better aquaplaning perfor-
mance. To benefit, however, you must
ensure that the tires rotate in the direction
specified.
An arrow on the sidewall indicates the in-
tended direction
of tire rotation.Checking tire inflation pressure
Correct the tire pressure only when tires
are cold.
Regularly check your tire pressure at inter-
vals of no more than 14 days. If the tires are warm you should only cor-
rect the tire pressure if it is too low for cur-
rent operating conditions.
A table on the fuel filler flap lists the spec-
ified tire inflation pressures for warm and
cold tires as well as for various operating
conditions.
Warning!
G
Tires and spare tire should be replaced after
six years, regardless of the remaining tread.!Keep unmounted tires in a cool, dry
place with as little exposure to light as
possible. Protect tires from contact
with oil, grease and gasoline.
Warning!
G
If the tire pressure drops repeatedly:

Check the tires for punctures from for-
eign objects.


Check to see whether air is leaking from
the valves or from around the rim.
iThe pressures listed for light loads are
minimum values offering high driving
comfort.
Increased inflation pressures listed for
heavier loads may also be used for light
loads. These higher pressures produce
favorable handling characteristics. The
ride of the vehicle, however, will be
somewhat harder. Never exceed the
max. values or inflate tires below the
min. values listed in the fuel filler flap.