Page 170 of 400

170 Controls in detailAutomatic climate control*Air conditioning
The air conditioning is operational while
the engine is running and cools the interior
air to the temperature set by the operator.
Deactivating
It is possible to deactivate the air condi-
tioning (cooling) function of the automatic
climate control system. The air in the
vehicle will then no longer be cooled or
dehumidified.
Press button° (
page 163).
The indicator lamp on the button
comes on.Activating
Moist air can fog up the windows. You can
dehumidify the air with the air condi-
tioning.
Press button° (
page 163).
The indicator lamp on the button goes
out.
The air conditioning uses the
refrigerant R134a. This refrigerant is free
of CFCs which are harmful to the ozone
layer.
iCondensation may drip out from under-
neath the vehicle. This is normal and
not an indication of a malfunction.
!If the air conditioning cannot be turned
on again, this indicates that the air
conditioning is losing refrigerant. The
compressor has turned itself off.
Have the air conditioning checked at
the nearest authorized Mercedes-Benz
Center.
Page 251 of 400

251 Operation
At the gas station
Check regularly and before a long trip
1Coolant level
For more information on coolant, see
“Coolant level” (
page 257).
2Brake fluid (fuse box cover removed)
Removing fuse box cover
(
page 333).
3Windshield washer and headlamp
cleaning system*
For more information on filling up the
washer reservoir, see “Windshield
washer system and headlamp cleaning
system*” (
page 259).Engine oil level
For more information on engine oil level,
see “Engine oil” (
page 253).
Opening hood (
page 252).
Vehicle lighting
Check function and cleanliness. For more
information on replacing light bulbs, see
“Replacing bulbs” (page 310).
Exterior lamp switch (page 102).
Tire inflation pressure
More information on tire inflation pressure
(
page 261).
!If you find that the brake fluid in the
brake fluid reservoir has fallen to the
minimum mark or below, have the
brake system checked for brake pad
thickness and leaks immediately.
Notify an authorized Mercedes-Benz
Center immediately. Do not add brake
fluid as this will not solve the problem.
For more information, see “Practical
hints” (
page 275).
Page 253 of 400

253 Operation
Engine compartment
Closing
Let the hood drop from a height of
approximately 1ft (30cm).
The hood will lock audibly.
Check to make sure the hood is fully
closed.
If you can raise the hood at a point
above the headlamps, then it is not
properly closed. Open it again and let it
drop with somewhat greater force.
Engine oil
The amount of oil your engine needs will
depend on a number of factors, including
driving style. Higher oil consumption can
occur when
the vehicle is new
the vehicle is driven frequently at
higher engine speeds
Engine oil consumption checks should only
be made after the vehicle break-in period.
Warning!
G
The engine is equipped with a transistorized
ignition system. Because of the high voltage
it is dangerous to touch any components
(ignition coils, spark plug sockets, diagnos-
tic socket) of the ignition system
with the engine running
while starting the engine
if ignition is “on” and the engine is
turned manually
Warning!
G
Be careful that you do not close the hood on
anyone.
iDo not use any special lubricant addi-
tives, as these may damage the drive
assemblies. Using special additives not
approved by Mercedes-Benz will
restrict your warranty entitlement.
More information on this subject is
available at any Mercedes-Benz
Center.
Page 254 of 400

254 OperationEngine compartmentChecking engine oil level with the
control system
When checking the oil level the vehicle
must
be parked on level ground
be at normal operating temperature
have been stationary for at least five
minutes with the engine turned off
To check the engine oil level via the
multifunction display, do the following:
Turn the SmartKey in the starter switch
to position2.
The standard display (
page 113) should
appear in the multifunction display.
Press buttonk orj on the
steering wheel until the following
message is seen in the multifunction
display:ENGINE OIL LEVEL
MEASURING NOW
MEASURE. CORRECT
ONLY IF VEH. LEVEL
One of the following messages will
subsequently appear in the indicator:
ENGINE OIL LEVEL
OK
ADD 1.0 Qt. TO
REACH MAX. OIL LEVEL!(Canada:
1.0 LITER
)
ADD 1.5 Qts. TO
REACH MAX. OIL LEVEL!(Canada:
1.5 LITERS
)
ADD 2.0 Qts. TO
REACH MAX. OIL LEVEL!(Canada:
2.0 LITERS
)
If necessary, add engine oil.
For adding engine oil see (
page 255).
More information on engine oil can be
found in the “Technical data” section
(
page 349) and (
page 352).
Other display messages
If the SmartKey is not turned to position2
in the starter switch, the following
message will appear:
FOR ENGINE OIL LEVEL
SWITCH ON IGNITION!
Switch on the ignition.iIf you want to interrupt the checking
procedure, press thek orj
button on the multifunction steering
wheel.
Page 255 of 400

255 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.
More information on messages in the
display concerning engine oil can be found
in the “Practical hints” section
(
page 291). 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
portfolio.
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 Products pamphlet that meets
the specification indicated on the oil
filler cap. Using engine oils of other
specification may cause the FSS to
incorrectly determine the next service
interval and will result in engine dam-
age not covered by the Mercedes-Benz
Limited Warranty.
Page 256 of 400

256 OperationEngine compartmentC 230 Kompressor Sport1Filler cap
Unscrew filler cap1 from filler neck.
Add engine oil as required. Be careful
not to overfill with oil.
Be careful not to spill any oil when adding.
Avoid environmental damage caused by oil
entering the ground or water.
Screw filler cap1 back on filler neck.
C 240 , and C 320 (all models), C 32 AMG1Filler cap
Unscrew filler cap1 from filler neck.
Add engine oil as required. Be careful
not to overfill with oil.Be careful not to spill any oil when adding.
Avoid environmental damage caused by oil
entering the ground or water.
Screw filler cap1 back on filler neck.
More information on engine oil can be
found in the “Technical data” section
(
page 349) and (
page 352).
Transmission fluid level
The transmission fluid level does not need
to be checked. If you notice transmission
fluid loss or gear shifting malfunctions,
have an authorized Mercedes-Benz Center
check the transmission.
!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.
!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.
Page 257 of 400

257 Operation
Engine compartment
Coolant level
The engine coolant is a mixture of water
and anticorrosion/antifreeze. To check
the coolant level, the vehicle must be
parked on level ground and the engine
must be cool.
The coolant expansion tank is located on
the passenger side of the engine compart-
ment.
1Coolant expansion tank
Using a rag, turn cap slowly approxi-
mately one half turn to the left to
release any excess pressure.
Continue turning the cap to the left and
remove it.
The coolant level is correct if the level
for cold coolant: reaches the black
top part of the reservoir
for warm coolant: is approx. 0.6 in
(1.5 cm) higher
Add coolant as required.
Replace and tighten cap.
For more information on coolant, see
“Coolants” (
page 356).
Warning!
G
In order to avoid any possibly serious burns:
Use extreme caution when opening the
hood if there are any signs of steam or
coolant leaking from the cooling system,
or if the coolant temperature gauge indi-
cates that the coolant is overheated.
Do not remove pressure cap on coolant
reservoir if engine temperature is
above 194°F (90°C). Allow engine to
cool down before removing cap. The
coolant reservoir contains hot fluid and
is under pressure.
Using a rag, slowly open the cap
approximately
1/2 turn to relieve excess
pressure. If opened immediately, scald-
ing hot fluid and steam will be blown out
under pressure.
Do not spill antifreeze on hot engine
parts. Antifreeze contains ethylene
glycol which may burn if it comes into
contact with hot engine parts.
Page 258 of 400

258 OperationEngine compartmentBattery
Your vehicle’s battery is located in the
engine compartment (
page 323).
The battery should always be sufficiently
charged in order to achieve its rated
service life. Refer to Service Booklet for
battery maintenance intervals.
If you use your vehicle mostly for short-dis-
tance trips, you will need to have the bat-
tery charge checked more frequently.
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.