2005 MERCEDES-BENZ C COUPE service

278 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 an
authorized Mercedes-Benz Center.
All checks and service work on the brake
system should be carried out by qualified
technicians only. Contact an authorized
Mercedes-Benz Center.
Install only brake pads and brake fluid
recommended 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
effect. Maintain a safe distance from vehi-
cles 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
accident.
!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 82).
Warning!
G
If other than recommended brake pads are
installed, or other than recommended brake
fluid is used, the braking properties of the
vehicle can be degraded to an extent that
safe braking is substantially impaired. This
could result in an accident.

284 OperationDriving instructionsStanding water
Passenger 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
an authorized Mercedes-Benz Center.Control and operation of radio
transmitter
COMAND*, radio and telephone*
!Do not drive through flooded areas or
water of unknown depth. Before driving
through water, determine its depth.
Never accelerate before driving into
water. The bow wave could force water
into the engine and auxiliary equip-
ment, thus damaging them.
If you must drive through standing wa-
ter, drive slowly to prevent water from
entering the passenger compartment
or the engine compartment. Water in
these areas could cause damage to
electrical components or wiring of the
engine or transmission, or could result
in water being ingested by the engine
through the air intake causing severe
internal engine damage. Any such
damage is not covered by the
Mercedes-Benz Limited Warranty.
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
objects.
Warning!
G
Please do not forget that your primary
responsibility 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 44 feet (approximate-
ly 14 m) every second.
1Observe all legal requirements

286 OperationDriving instructionsEmission 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
according to factory specifications. Any
adjustments on the engine should,
therefore, be carried out only by qualified
Mercedes-Benz Center authorized
technicians.
Engine adjustments should not be altered
in any way. Moreover, the specified service
jobs must be carried out regularly
according to Mercedes-Benz servicing
requirements. For details refer to the
Maintenance Booklet.
Coolant temperature
During severe operating conditions and
stop-and-go city traffic, the coolant tem-
perature may rise close to approximately
248°F (120°C).
The engine should not be operated with
the coolant temperature over 248°F
(120°C). Doing so may cause serious
engine damage which is not covered by
the Mercedes-Benz Limited Warranty.
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.

289 Operation
At the gas station

Open the fuel filler flap by pushing at
the point indicated by the arrow1.
The fuel filler flap springs open.

Turn the fuel cap counterclockwise and
hold on to it until possible pressure is
released.

Take off the cap and set it in direction
of arrow3 the recess on 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 up or
overfill.

Replace the fuel cap by turning it clock-
wise.
You should hear the fuel cap engage.

Close the fuel filler flap.
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.
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 431).
iLeaving the engine running and the fuel
cap open can cause the ú malfunc-
tion indicator lamp (USA only) or the
± malfunction indicator lamp
(Canada only) to illuminate.
For more information, see “Practical
hints” section (
page 342).

294 OperationEngine compartmentIf you see the message:Observe waiting time
If engine is at operating temperature,
wait five minutes before repeating
check procedure.

If engine is not at operating tempera-
ture yet, 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 operating tempera-
ture, wait five minutes before checking
oil.

If the engine is not at operating temper-
ature yet, 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 an authorized
Mercedes-Benz Center.
For more information on messages in the
display concerning engine oil, see “Practi-
cal hints” (
page 363).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 and oil
filters required for vehicles with
Maintenance System (U.S. vehicles) or
FSS (Canada vehicles). For a listing of
approved engine oils and oil filters,
refer to the Factory Approved Service
Products pamphlet in your vehicle
literature portfolio, or contact an
authorized Mercedes-Benz Center.
Using engine oils and oil filters of spec-
ification other than those expressly
required for the Maintenance System
(U.S. vehicles) or FSS (Canada vehi-
cles), or changing of oil and oil filter at
change intervals longer than those
called for by the Maintenance System
(U.S. vehicles) or FSS (Canada vehi-
cles) will result in engine damage not
covered by the Mercedes-Benz Limited
Warranty.

300 OperationTires and wheelsSee an authorized Mercedes-Benz Center
for information on tested and
recommended rims and tires for summer
and winter operation. They can also offer
advice 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. The operating safety of the
vehicle cannot be assured when such tires
are used.
Important guidelines

Only use 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 inflation pressure loss and
damage to the tire beads.


If vehicle is heavily loaded, check tire
inflation 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 an authorized
Mercedes-Benz Center for further informa-
tion. If incorrectly sized rims and tires are
mounted:

The wheel brakes or suspension
components can be damaged.


The operating clearance of the wheels
and the tires may no longer be correct.
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, only use genuine
Mercedes-Benz wheel bolts specified for the
particular rim type. Failure to do so can
result in the bolts loosening and possibly an
accident.

301 Operation
Tires and wheels
Tire care and maintenance
Regularly check your tire inflation pressure
at least once a month. For more informa-
tion on checking tire inflation pressure,
see “Recommended tire inflation pres-
sure” (
page 309).Tire inspection
Every time you check your tire inflation
pressure, you should also inspect your
tires for the following:


excessive treadwear (
page 302)


cord or fabric showing through the
tire’s rubber


bumps, bulges, cuts, cracks or splits in
the tread or side of the tire
Replace the tire if you find any of the above
conditions.
Make sure you also inspect the spare tire
periodically for condition and inflation.
Spare tires will age and become worn over
time even if never used, and thus should be
inspected and replaced when necessary.Life of tire
The service life of a tire is dependent upon
varying factors including but not limited to:


Driving style


Tire inflation pressure


Distance driven
Warning!
G
Regularly check the tires for damage. Dam-
aged tires can cause tire inflation pressure
loss. As a result, you could lose control of
your vehicle.
Worn, old tires can cause accidents. If the
tire tread is badly worn, or if the tires have
sustained damage, replace them.
Warning!
G
Tires and spare tire should be replaced after
six years, regardless of the remaining tread.

315 Operation
Tires and wheels
Rim diameter
The rim diameter4 (
page 314) is the
diameter of the bead seat, not the
diameter of the rim edge. Rim diameter is
indicated in inches (in).
Tire load rating
The tire load rating5 (page 314) is a
numerical code associated with the
maximum load a tire can support.
For example, a load rating of 91 corre-
sponds to a maximum load of 1 356 lbs
(615 kg) the tire is designed to support.
See also “Maximum tire load”
(
page 319) where the maximum load as-
sociated with the load index is indicated in
kilograms and lbs.For additional information on tire load
rating, see “Load identification”
(
page 317).
Warning
G
The tire load rating must always be at least
half of the GAWR (
page 323) of your vehi-
cle. Otherwise, tire failure may be the result
which may cause an accident and/or seri-
ous personal injury to you or others.
Always replace rims and tires with the same
designation, manufacturer and type as
shown on the original part.
Warning!
G
Do not overload the tires by exceeding the
specified load limit or vehicle capacity
weight as indicated on the placard located
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.
iTire load rating5 (
page 314) and
tire speed rating6 (page 314) are
also referred to as “service descrip-
tion”.