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

405 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
BCheck
Coolant Level
See Operator’s Manu-
alThe coolant level is too low.Add coolant (page 329).
If you have to add coolant frequently, have
the cooling system checked at an autho-
rized Mercedes-Benz Center.
Warning!G
Do not spill antifreeze on hot engine parts.
Antifreeze contains ethylene glycol which
may burn if it comes into contact with hot
engine parts. You could be seriously burned.
!Do not ignore the low engine coolant level
warning. Extended driving with the message and
symbol displayed may cause serious engine
damage not covered by the Mercedes-Benz Lim-
ited Warranty.
Do not drive without a sufficient amount of cool-
ant in the cooling system. The engine will over-
heat, causing major engine damage.

415 Practical hints
What to do if …?
When the message Check Engine Oil At
Next Refueling
appears while the engine
is running and at operating temperature,
the engine oil level has dropped to approx-
imately the minimum level.
When this occurs, the warning will first
come on intermittently and then stay on if
the oil level drops further.
Visually check for oil leaks. If no obvious oil
leaks are noted, continue to drive to the
nearest service station where the engine
oil should be topped to the required level
with an approved oil specified in the Facto-
ry Approved Service Products pamphlet.
For information on approved engine oils,
refer to the Factory Approved Service
Products pamphlet (USA only) or contact
an authorized Mercedes-Benz Center.
Display Possible cause/consequencePossible solution
ùCheck
Engine Oil
At Next RefuelingThe engine oil level has dropped to approx-
imately the minimum level.Check the engine oil level (page 327) and
add engine oil as required (
page 328).
If you must add engine oil frequently, have
the engine checked for possible leaks.
!The engine oil level warnings should not be
ignored. Extended driving with the symbol dis-
played could result in serious engine damage
that is not covered by the Mercedes-Benz Limit-
ed Warranty.

446 Practical hints
Battery
Your vehicle’s battery is located in the
engine compartment.
The battery should always be sufficiently
charged in order to achieve its rated ser-
vice life. Refer to Maintenance Booklet for
battery maintenance intervals.
If you use your vehicle mostly for
short-distance trips, you will need to have
the battery 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.
Large 12-volt storage batteries contain
lead. Recycling of batteries is the preferred
method of disposal. Many states require
sellers of batteries to accept old batteries
for recycling.
!Do not tow-start the vehicle.
Warning!G
Observe all safety instructions and precau-
tions when handling automotive batteries.
Risk of explosion.
Fire, open flames and smoking
are prohibited when handling
batteries. Avoid creating sparks.
Battery acid is caustic. Do not
allow it to come into contact
with skin, eyes or clothing.
Wear suitable protective cloth-
ing, especially gloves, apron and
faceguard.
Wear eye protection.
Rinse any acid spills immediate-
ly with clear water. Contact a
physician if necessary.
Keep children away.
Follow the instructions in this
Operator’s Manual.

447 Practical hints
Battery
1Filter box
2Clamps
Removing filter box: Release
clamps2.
Remove filter box.
Installing filter box: Insert filter box
properly.
Secure it with clamps2.
Warning!G
Failure to follow these instructions can re-
sult in severe injury or death.
Observe all safety instructions and
precautions when handling automotive
batteries (
page 446).
Never lean over batteries while connecting,
you might get injured.
Battery fluid contains sulfuric acid. Do not
allow this fluid to come in contact with eyes,
skin or clothing. In case it does, immediately
flush affected area with water and seek
medical help if necessary.
A battery will also produce hydrogen gas,
which is flammable and explosive. Keep
flames or sparks away from battery, avoid
improper connection of jumper cables,
smoking, etc.
!Never loosen or detach battery terminal
clamps while the engine is running or the
SmartKey is in the starter switch. Otherwise the
alternator and other electronic components
could be severely damaged.
Have the battery checked regularly at an autho-
rized Mercedes-Benz Center.
Refer to Maintenance Booklet for maintenance
intervals or contact an authorized
Mercedes-Benz Center for further information.
Warning!G
Do not place metal objects on the battery as
this could result in a short circuit.
Use leak-proof batteries only to avoid the
risk of acid burns in the event of an
accident.
!Do not connect any consumers directly to
the battery or it will be discharged.

451 Practical hints
Jump starting
Jump starting
If the battery is discharged, the engine can
be started with jumper cables and the
battery of another vehicle. Observe the
following:

Jump starting should only be performed
when the engine and catalytic
converter are cold.

Do not start the engine if the battery is
frozen. Let the battery thaw out first.

Only use a12-volt battery to jump start
your vehicle. Jump starting with a high-
er voltage battery could damage the ve-
hicle’s electrical system, which will not
be covered by the Mercedes-Benz
Limited Warranty.

Only use jumper cables with sufficient
cross-section and insulated terminal
clamps.

Always make sure the jumper cables
are not on or near pulleys, fans or other
parts that move when an engine is
started or running.
Warning!G
Failure to follow these directions will cause
damage to the electronic components, and
can lead to a battery explosion and severe
injury or death.
Never lean over batteries while connecting
or jump starting, you might get injured.
Battery fluid contains sulfuric acid. Do not
allow this fluid to come in contact with eyes,
skin or clothing. In case it does, immediately
flush affected area with water, and seek
medical help if necessary.
A battery will also produce hydrogen gas,
which is flammable and very explosive. Keep
flames or sparks away from battery, avoid
improper connection of jumper cables,
smoking, etc.
Attempting to jump start a frozen battery
can result in it exploding, causing personal
injury.
Read all instructions before proceeding.
!Vehicles with automatic transmission*
and/or 4MATIC:
Do not tow-start the vehicle.
!Avoid repeated and lengthy starting
attempts.
Do not attempt to start the engine using a bat-
tery quick charge unit.
If engine does not run after several unsuccessful
starting attempts, have it checked at the nearest
authorized Mercedes-Benz Center.
Excessive unburned fuel generated by repeated
failed starting attempts may damage the catalyt-
ic converter and may present a fire risk.
Make sure the jumper cables do not have loose
or missing insulation.
Make sure the cable clamps do not touch any
other metal part while the other end is still at-
tached to a battery.
Warning!G
Keep flames or sparks away from battery.
Do not smoke.
Observe all safety instructions and precau-
tions when handling automotive batteries
(
page 446).

452 Practical hints
Jump starting
The battery is located in the engine com-
partment on the right hand side. For jump
starting, use the under hood terminals in
front of the battery.
Make sure the two vehicles do not
touch.
Turn off all electrical consumers,
except hazard warning flashers or work
lights.
Apply the parking brake (page 134).
Make sure gear selector lever* is set to
positionP (manual transmission to
Neutral).
Open the hood (page 326).
Slide red cover2 from positive under
hood terminal3 in direction of arrow. 1Positive terminal of charged battery
2Positive under hood terminal cover
3Positive under hood terminal in front of
discharged battery
4Negative under hood terminal
5Negative terminal of charged battery
Connect positive terminal1 of the
charged battery with positive under
hood terminal3 in front of the dis-
charged battery with the jumper cable.
Clamp cable to charged battery1
first.
Start the engine of the vehicle with the
charged battery and run at idle speed.
Connect negative terminal5 of the
charged battery to jumper cables and
attach other end to negative under
hood terminal4 on the vehicle. Clamp
cable to charged battery5 first
Start the engine of the disabled
vehicle.
You can now turn on the electrical con-
sumers. Do not switch on the headlamps
under any circumstances.
Remove the jumper cables first from
the negative terminals4 and5 and
then from the positive terminals3
and1.
You can now switch on the headlamps.
Slide red cover2 from positive under
hood terminal3 back.
Close the hood (page 326).
Have the battery checked at the near-
est authorized Mercedes-Benz Center.
!Never invert the terminal connections.

484 Technical data
Fuels, coolants, lubricants, etc.
Coolants
The engine coolant is a mixture of water
and anticorrosion/antifreeze, which pro-
vides:

Corrosion protection

Freeze protection

Boiling protection (by increasing the
boiling point)
The cooling system was filled at the factory
with a coolant providing freeze protection
to approximately -22°F (-30°C) and corro-
sion protection.
If the antifreeze mixture is effective to
-22°F (-30°C), the boiling point of the cool-
ant in the pressurized cooling system is
reached at approximately 266°F (130°C).The coolant solution must be used year
round to provide the necessary corrosion
protection and increase boil-over protec-
tion. Refer to Maintenance Booklet for re-
placement interval.
Coolant system design and coolant used
determine the replacement interval. The
replacement interval published in the
Maintenance Booklet is only applicable if
MB 325.0 Anticorrosion/Antifreeze solu-
tion or other Mercedes-Benz approved
products of equal specification are used to
renew the coolant concentration or bring it
back up to the proper level.
For information on other Mercedes-Benz
approved products of equal specification,
refer to the Factory Approved Service
Products pamphlet (USA only) or contact
an authorized Mercedes-Benz Center.
To provide important corrosion protection,
the solution must be at least 50% anticor-
rosion/antifreeze (equivalent to freeze
protection to approximately –35°F
[–37°C]).If you use a solution that is more than 55%
anticorrosion/antifreeze (freeze protec-
tion to approximately –49°F [–45°C]), the
engine temperature will increase due to
the lower heat transfer capability of the so-
lution. Therefore, do not use more than
this amount of anticorrosion/ antifreeze.
If the coolant level is low, water and
MB 325.0 Anticorrosion/Antifreeze
should be used to bring it up to the proper
level (have cooling system checked for
signs of leakage).
The water in the cooling system must meet
minimum requirements, which are usually
satisfied by normal drinking water. If you
are not sure about the water quality,
consult an authorized Mercedes-Benz
Center.
!Add premixed coolant solution only. Adding
water and MB 325.0 Anticorrosion/Antifreeze
separately from each other, could cause engine
damage not covered by the Mercedes-Benz Lim-
ited Warranty.

485 Technical data
Fuels, coolants, lubricants, etc.
Anticorrosion/antifreeze
Your vehicle contains a number of alumi-
num parts. The use of aluminum compo-
nents in motor vehicle engines
necessitates that anticorrosion/antifreeze
coolant used in such engines be specifical-
ly formulated to protect the aluminum parts. Failure to use such anticorrosion/
antifreeze coolant will result in a signifi-
cantly shortened service life.
Therefore, the following product is strongly
recommended for use in your vehicle:
Mercedes-Benz 325.0 Anticorrosion/
Antifreeze agent.Before the start of the winter season (or
once a year in hot southern regions), you
should have the anticorrosion/antifreeze
concentration checked. The coolant is also
regularly checked each time you bring your
vehicle to an authorized Mercedes-Benz
Center for service.
Anticorrosion/antifreeze quantity
ModelApprox. freeze protection
– 35°F (– 37°C)– 49°F (– 45°C)
C 3002.54 US qt. (2.4 l)2.79 US qt. (2.64 l)
C 3502.54 US qt. (2.4 l)2.79 US qt. (2.64 l)

488 Index
Phone cook 233
Radio operation 194
Satellite radio* operation 200
Sound settings 189
Surround sound* (Canada only) 190
SYS menu 192
SYS menu, Bluetooth
® settings 192
SYS menu, display settings 192
SYS menu, language settings 193
SYS menu, reset to factory
settings 193
Telephone menu* 222
Volume 189
Auto-dimming*, Rear view mirrors 100
Automatic central locking 80
Activating/deactivating
(Control system) 173
Automatic climate control (3-zone) see Cli-
mate control system
Automatic headlamp mode 109, 172
Automatic lighting control, Interior
lighting 115
Automatic shift program 144Automatic transmission
Accelerator position 142
Emergency operation (limp-home
mode) 146
Fluid 476, 477
Fluid level 328
Gear ranges 143
Gear shifting malfunctions 146
Hill start assist system 246
Kickdown 142
Shifting procedure 139
Starting the engine 127
Transmission fluid 328
Automatic transmission*
Automatic shift program 144
Gear selector lever 138
Gear selector lever control one-touch
gearshifting 145
Gear selector lever positions 140
Program mode selector switch 144
Aux socket 220B
Backrest 281
Backup lamps
Replacing bulbs 430, 431
Bar 356
BAS 60
Batteries, SmartKey
Checking battery condition 78
Replacing 428
Batteries, SmartKey with KEYLESS-GO*
(Canada only)
Checking battery condition 78
Replacing 428
Battery 448
Battery, vehicle 446
Charging 449
Discharged, Jump starting 451
Disconnecting 448
Message in display 399
Reconnecting 450
Removing 449
Bead 356
Beverage holder see Cup holder

490 Index
Dual-zone automatic climate
control 250
Front defroster 255
Rear climate control 268
Rear window defroster 256, 265
Residual engine heat and
ventilation 266
Setting the temperature 262
Temperature 253
Windshield, defogging 255
Clock 151
Setting time 170
Cockpit 24
Cold weather performance 483
COMAND* see separate COMAND
operating instructions
Combination switch 112
Corner-illuminating front fog
lamps* 112
High beam flasher 112
Turn signals 131
Windshield wipers 117
Control system 151
Multifunction display 151
Multifunction steering wheel 152
Resetting to factory default 165Control system menu 151
AUDIO 158
Menus overview 154
Navi* 158
Service menu 164
Settings menu 165
Standard display 156
TEL* 160
Trip computer 156
Vehicle status message
memory 164
Control system submenus 153, 155
Convenience 174
Instrument cluster 168
Lighting 171
Time/Date 170
Vehicle 173
Coolant 329
Adding 329
Anticorrosion/antifreeze mixing ratio
and quantity 484
Checking level 329
Messages in display 405
Temperature 321
Temperature gauge 27, 148Coolant level
Checking 329
Corner-illuminating front fog lamps* 112
Replacing bulbs 431
Cruise control 241
Activating 242
Canceling 243
Driving downhill 243
Driving uphill 243
Setting current speed 242
Setting to last stored speed
(“Resume” function) 245
Cruising range, fuel 483
Cup holder
In front seat armrest 287
In rear seat armrest 287
Curb weight 356