check engine MERCEDES-BENZ C300 4MATIC 2008 W204 Owner's Manual

Contents
At the gas station .............................. 322
Refueling ...................................... 322
Check regularly and
before a long trip.......................... 324
Engine compartment ......................... 325
Hood ............................................ 325
Engine oil ..................................... 327
Transmission fluid level ................ 328
Coolant level ................................ 329
Windshield washer system and
headlamp cleaning system* ......... 330
Tires and wheels ................................ 331
Important guidelines .................... 331
Tire care and maintenance........... 332
Direction of rotation ..................... 334
Loading the vehicle ...................... 334
Recommended tire
inflation pressure ......................... 339
Checking tire inflation pressure ... 341
Tire labeling.................................. 348
Load identification ....................... 352
DOT,
Tire Identification Number (TIN) ... 352
Maximum tire load ....................... 353
Maximum tire inflation pressure .. 354Uniform Tire Quality Grading
Standards (U.S. vehicles) .............. 354
Tire ply material ............................ 356
Tire and loading terminology......... 356
Rotating tires ................................ 359
Winter driving ..................................... 360
Winter tires ................................... 360
Snow chains.................................. 361
Maintenance....................................... 362
Maintenance
service indicator message ............ 362
Calling up the maintenance
service indicator display ............... 363
Resetting the maintenance
service indicator ........................... 363
Vehicle care........................................ 364
Cleaning and care of vehicle ......... 364
Practical hints.................................. 373
What to do if …? ................................. 374
Lamps in instrument cluster ......... 374
Air bag off indicator lamp ............. 385
Vehicle status messages in
the multifunction display .............. 387
Where will I find ...? ............................ 420
First aid kit.................................... 420
Vehicle jack, vehicle tool kit,
luggage bowl, Minispare wheel ..... 420
Unlocking/locking in an emergency .. 424
Unlocking the vehicle ................... 424
Locking the vehicle ....................... 425
Fuel filler flap ................................ 426
Manually unlocking the
transmission gear selector lever ... 426
Resetting activated head restraints.... 427
Replacing SmartKey batteries ............ 428
Replacing bulbs .................................. 430
Bulbs............................................. 431
Replacing bulbs for front lamps .... 432
Replacing bulbs for rear lamps ..... 436
Replacing wiper blades ...................... 438
Removing wiper blades ................. 439
Installing wiper blades .................. 439

21 At a glance
Exterior view
ItemPage
1Trunk

Unlocking

Opening and closing

Minispare wheel

Vehicle tool kit
269
269
441
420
2Rear lamps431
3Rear window, defrosting265
4Fuel filler flap
Refueling
Gasoline322
322
481
5Doors

Locking and unlocking

Opening and closing

Unlocking/locking in an
emergency
70
70
424
6Exterior rear view mirror

Adjusting97
ItemPage

Auto-dimming rear view
mirrors*

Power folding exterior rear
view mirrors*

Parking position*
(Canada only)
97
100
98
101
7Tires and wheels

Checking tire inflation
pressure

Tire Pressure Monitoring
System (TPMS), (USA only)

Run Flat Indicator (Canada
only)

General information

Minispare wheel

Flat tire
331
341
344
342
331
422
440
8Towing the vehicle
Installing towing eye bolt453
455
ItemPage
9Headlamp cleaning system*112
aFront lamps431
bHood, opening
Engine oil
Coolant
Battery325
327
329
446
cWindshield wipers
Wiper blades, replacing
Wiper blades, cleaning117
438
368
dWindshield
Front window, defrosting
Cleaning with wiper fluid
Cleaning
264
119
368
eRoofs

Power tilt/sliding sunroof

Panorama roof with power
tilt/sliding panel*
273
276

42 Safety and Security
Occupant safety
Both driver and the front passenger should
always use the 5/indicator lamp
as an indication of whether or not the front
passenger is properly positioned.
iIf your seat, including your trim cover and
cushion needs to be serviced in any way, take
the vehicle to an authorized Mercedes-Benz
Center.
Only seat accessories approved by
Mercedes-Benz may be used.Warning!G
If the 5/indicator lamp illuminates
when an adult or someone larger than a
small individual is in the front passenger
seat, have the front passenger re-position
himself or herself in the seat until the
5/indicator lamp goes out, or check
whether objects are caught under or around
the seat.
In the event of a collision, the air bag control
unit will not allow front passenger front air
bag deployment when the OCS classified
the front passenger seat occupant as being
up to or less than the weight of a typical
12-month-old child in a standard child
restraint or if the front passenger seat is
sensed as being empty.
When the OCS senses that the front passen-
ger seat occupant is classified as being up
to or less than the weight of a typical
12-month-old child in a standard child
restraint, the 5/indicator lamp will
illuminate when the engine is started and
remain illuminated, indicating that the front
passenger front air bag is deactivated.
When the OCS senses that the front passen-
ger seat is classified as being empty, the
5/indicator lamp will illuminate
when the engine is started and remain
illuminated, indicating that the front
passenger front air bag is deactivated.
When the OCS senses that the front passen-
ger seat occupant is classified as being
heavier than the weight of a typical
12-month-old child seated in a standard
child restraint or as being a small individual
(such as a young teenager or a small adult),
the 5/indicator lamp will illuminate
for approximately 6 seconds when the
engine is started and then, depending on
occupant weight sensor readings from the
seat, remain illuminated or go out. With the
5/indicator lamp illuminated, the
front passenger front air bag is deactivated.
With the 5/indicator lamp out, the
front passenger front air bag is activated.

73 Controls in detail
Locking and unlocking
Global locking: Press button‹.
With the trunk and doors closed:

All turn signal lamps flash three
times.

An acoustic signal sounds three
times.

The locking knobs in the doors
move down.

The anti-theft alarm system is
armed.
Restoring to factory setting: Press
and hold buttonsŒ and‹ si-
multaneously for about 6 seconds until
battery check lamp5 (
page 70)
flashes twice.SmartKey with KEYLESS-GO*
(Canada only)
Vehicles equipped with KEYLESS-GO come
with two SmartKeys with KEYLESS-GO,
each with remote control and a removable
mechanical key.
The KEYLESS-GO function is integrated
into the SmartKey. On these vehicles, the
validity of the SmartKey with KEYLESS-GO
is checked every time you grasp an outside
door handle.
With the KEYLESS-GO function, you can
lock and unlock the vehicle without using
the remote control buttons on the
SmartKey and start the engine without in-
serting the SmartKey in the starter switch.
The SmartKey with KEYLESS-GO centrally
locks and unlocks, when set to factory set-
tings (
page 76):

the doors

the trunk

the fuel filler flap
SmartKey with KEYLESS-GO
1‹ Lock button
2ŠOpening button for trunk
(
page 269)
3Locking tab for mechanical key
4ΠUnlock button
5Battery check lamp
6ÂPanic button (
page 58)
iWhen any outside door handle other than
the driver’s outside door handle is grasped, the
vehicle is always centrally unlocked.
!To prevent possible malfunction, avoid ex-
posing the SmartKey with KEYLESS-GO to high
levels of electromagnetic radiation.

74 Controls in detail
Locking and unlocking
Warning!G
When leaving the vehicle, always take the
SmartKey with KEYLESS-GO* with you and
lock the vehicle. Do not leave children unat-
tended in the vehicle, or with access to an
unlocked vehicle. A child’s unsupervised ac-
cess to a vehicle could result in an accident
and/or serious personal injury.
They could start the vehicle with a valid
SmartKey with KEYLESS-GO left in the vehi-
cle or with the KEYLESS-GO button on the
starter switch, or they could release the
parking brake, thereby putting themselves
and others in danger. Switch off the engine
and take the SmartKey with KEYLESS-GO
with you even if you are only leaving the ve-
hicle for a short while.
Warning!G
To prevent possible personal injury, always
keep hands and fingers away from the door
or trunk lid opening when closing a door or
the trunk. Be especially careful when small
children are around.
Before closing doors, make sure there is no
possibility of someone getting caught in a
door during closing.
iUSA only:
This device complies with Part 15 of the FCC
Rules. Operation is subject to the following two
conditions:
(1) This device may not cause harmful interfer-
ence, and
(2) this device must accept any interference re-
ceived, including interference that may
cause undesired operation.
Any unauthorized modification to this device
could void the user’s authority to operate the
equipment.
iCanada only:
This device complies with RSS-210 of Industry
Canada. Operation is subject to the following
two conditions:
(1) This device may not cause interference, and
(2) this device must accept any interference re-
ceived, including interference that may
cause undesired operation of the device.
Any unauthorized modification to this device
could void the user’s authority to operate the
equipment.
iYou can also open and close the door win-
dows and tilt/sliding sunroof, or the panorama
roof with power tilt/ sliding panel* using the
SmartKey with KEYLESS-GO (
page 123).
!If you cannot lock or unlock the vehicle with
the SmartKey with KEYLESS-GO, then either the
batteries in the SmartKey with KEYLESS-GO are
discharged, the SmartKey with KEYLESS-GO is
malfunctioning or the vehicle batteries are
drained.

Check the batteries in the SmartKey with
KEYLESS-GO and replace them if necessary
(
page 428).

75 Controls in detail
Locking and unlocking
Important notes on using KEYLESS-GO

You can also use the SmartKey with
KEYLESS-GO like a normal SmartKey
(
page 70).
The starter switch is under the
KEYLESS-GO button. Pull the
KEYLESS-GO button out in order to ac-
cess the starter switch.

You can combine KEYLESS-GO func-
tions with normal SmartKey functions
(e.g. unlocking with KEYLESS-GO and
locking with button ‹).

Always carry the SmartKey with
KEYLESS-GO with you.

Never store the SmartKey with
KEYLESS-GO together with:

Electronic items such as a tele-
phone or another SmartKey with
KEYLESS-GO

Metallic objects such as coins or
metal foil
Doing so could impair the function of
the KEYLESS-GO system.

To lock or unlock the vehicle, the
SmartKey with KEYLESS-GO must be
located outside the vehicle within ap-
proximately 3 ft (1 m) of a door or the
trunk lid.

If the vehicle has been parked for more
than 72 hours, you must pull an outside
door handle in order to activate the
KEYLESS-GO function.

In order to start the engine with the
SmartKey with KEYLESS-GO:

The SmartKey with KEYLESS-GO
must be located in the vehicle.

The KEYLESS-GO start/stop button
must be inserted in the starter
switch (
page 84).

The brake pedal must be firmly de-
pressed. Do not depress the accel-
erator.

If the SmartKey with KEYLESS-GO is
positioned farther away from the vehi-
cle, the system may no longer recog-
nize the SmartKey with KEYLESS-GO.
The vehicle then cannot be locked or
the engine started via the KEYLESS-GO
system.

If the SmartKey with KEYLESS-GO is re-
moved from the vehicle (e.g. if passen-
ger exits the vehicle with the SmartKey
with KEYLESS-GO)

when pressing the KEYLESS-GO
start/stop button or trying to lock
the vehicle with the outside door
handle the message
Key not rec-
ognized
appears in the multifunc-
tion display

Use the mechanical key to unlock the driv-
er’s door (
page 424) and trunk
(
page 425).

Use the mechanical key to lock and trunk
(
page 272).

Have the vehicle batteries and their connec-
tions checked (
page 446).
If the SmartKey with KEYLESS-GO is malfunc-
tioning, contact Roadside Assistance or an
authorized Mercedes-Benz Center.

82 Controls in detail
Starter switch positions
SmartKey
Starter switch
0For removing SmartKey1Power supply for some electrical con-
sumers, such as seat adjustment
2Ignition (power supply for all electrical
consumers) and driving position.
All lamps (except high beam headlamp
indicator lamp and turn signal indicator
lamps unless activated) in the instru-
ment cluster come on. If a lamp in the
instrument cluster fails to come on
when the ignition is switched on, have
it checked and replaced if necessary.
If a lamp in the instrument cluster re-
mains on after starting the engine or
comes on while driving, refer to “Lamps
in instrument cluster” (
page 374).
3Starting position
For information on starting the engine us-
ing the SmartKey, see “Starting: Make sure
the gear selector lever is set to P.”
(
page 127).
Warning!G
When leaving the vehicle, always remove the
SmartKey or SmartKey with KEYLESS-GO*
from the starter switch, take it with you, and
lock the vehicle. Do not leave children unat-
tended in the vehicle, or with access to an
unlocked vehicle. A child’s unsupervised ac-
cess to a vehicle could result in an accident
and/or serious personal injury.
iWhen you switch on the ignition, the
indicator and warning lamps (except high beam
headlamp indicator lamp and turn signal indica-
tor lamps unless activated) in the instrument
cluster come on. The indicator and warning
lamps (except high beam headlamp indicator
lamp and turn signal indicator lamps if activated)
should go out when the engine is running. This in-
dicates that the respective systems are opera-
tional.
iVehicles with automatic transmission*: The
SmartKey can only be removed from the starter
switch with the gear selector lever in positionP.
iIf the SmartKey is left in starter switch
position0 for an extended period of time, it can
no longer be turned in the switch. In this case,
the steering is locked. To unlock, remove
SmartKey from starter switch and reinsert.
!If the SmartKey cannot be turned in the
starter switch, the battery may not be sufficient-
ly charged.

Check the battery and charge it if necessary
(
page 446).

Get a jump start (page 451).
To prevent accelerated battery discharge or a
completely discharged battery, always remove
the SmartKey from the starter switch when the
engine is not in operation.

84 Controls in detail
Starter switch positions
The SmartKey with KEYLESS-GO must be
located in the vehicle.
Make sure the gear selector lever is set
toP.
Do not depress the brake pedal.
1KEYLESS-GO start/stop button
(Canada only)
Position 0
Before you press the KEYLESS-GO
start/stop button, the vehicle’s on-board
electronics have status 0 (as with
SmartKey removed).Position 1
Press the KEYLESS-GO start/stop but-
ton once.
This supplies power for some electrical
consumers, such as seat adjustment.
Ignition (or position 2)
Press the KEYLESS-GO start/stop but-
ton twice.
This supplies power for all electrical
consumers.
All lamps (except high beam headlamp
indicator lamp and turn signal indicator
lamps unless activated) in the instru-
ment cluster come on. If a lamp in the
instrument cluster fails to come on
when the ignition is switched on, have
it checked and replaced if necessary. If a lamp in the instrument cluster re-
mains on after starting the engine or
comes on while driving, refer to “Lamps
in instrument cluster” (
page 374).
For information on starting the engine us-
ing the KEYLESS-GO start/stop button,
see “Starting: Make sure KEYLESS-GO
start/stop button is inserted in the starter
switch (e page 83).” (
page 128).
iIf you now press the KEYLESS-GO
start/stop button

once again, the ignition (position2) is
switched on

twice, the power supply is again switched off
iIf you now press the KEYLESS-GO
start/stop button once, the power supply is
again switched off.
iWhen you switch on the ignition, the indica-
tor and warning lamps (except high beam head-
lamp indicator lamp and turn signal indicator
lamps unless activated) in the instrument cluster
come on. The indicator and warning lamps (ex-
cept high beam headlamp indicator lamp and
turn signal indicator lamps if activated) should go
out when the engine is running. This indicates
that the respective systems are operational.


117 Controls in detail
Windshield wipers
Windshield wipers
Combination switch
1Switching on windshield wipers
2Single wipe
Wiping with windshield washer fluid
Switch on the ignition.
!If the windshield wipers leave smears on the
windshield after the car has been driven through
an automatic car wash, then wax or other resi-
due is on the windshield. Shortly after washing
the car in an automatic car wash, clean the wind-
shield with windshield washer fluid.
!Do not operate the windshield wipers when
the windshield is dry. Dust that accumulates on
a windshield might scratch the glass and/or
damage the wiper blades when wiping occurs on
a dry windshield. If it is necessary to operate the
windshield wipers in dry weather conditions, al-
ways operate the windshield wipers with wind-
shield washer fluid.
!If anything blocks the windshield wipers
(leaves, snow, etc.), switch them off immediate-
ly.

For safety reasons, stop the vehicle in a safe
location and,

remove the SmartKey from starter
switch
or

turn off the engine by pressing the
KEYLESS-GO* start/stop button and
open the driver’s door (with the driver’s
door open, starter switch is in
position0, same as with SmartKey re-
moved from starter switch)

engage the parking brake
before attempting to remove any blockage.

Remove blockage.

Turn the windshield wipers on again.
If the windshield wipers fail to function at all in
combination switch position U or V,

set the combination switch to the next
higher wiper speed

have the windshield wipers checked at the
nearest authorized Mercedes-Benz Center

132 Controls in detail
Driving and parking
Problems while driving
The engine runs erratically and misfires

An ignition cable may be damaged.

The engine electronics may not be op-
erating properly.

Unburned gasoline may have entered
the catalytic converter and damaged it.
Give very little gas.
Have the problem repaired at an autho-
rized Mercedes-Benz Center as soon as
possible.The coolant temperature is above
248°F (120°C)
The coolant is too hot and is no longer
cooling the engine.
Stop the vehicle in a safe location as
soon as possible and turn off the en-
gine. Allow engine and coolant to cool
off.
Check the coolant level and add cool-
ant if necessary (
page 329).In case of accident
If the vehicle is leaking gasoline:
Do not start the engine under any cir-
cumstances.
Move away from vehicle.
Notify local fire and/or police authori-
ties.
If the extent of the damage cannot be de-
termined:
Notify an authorized Mercedes-Benz
Center.
If no damage can be determined on the

major assemblies

fuel system

engine mount:
Start the engine in the usual manner.
iTo signal minor directional changes such as
changing lanes, press combination switch only
to point of resistance and release. The corre-
sponding turn signals will flash three times.
iExcessive coolant temperatures trigger a
warning message in the multifunction display
(
page 402).