Page 227 of 370

233 Operation
At the gas station
Check regularly and before a long trip
1Coolant level
More information on the coolant level
can be found in the “Operation” section
(
page 238).
2Brake fluid (fuse box cover removed)
More information on brake fluid can be
found in the “Technical data” section
(page 330).
3Windshield washer and headlamp
cleaning system
For more information on refilling the
reservoir, see the “Operation” section
(page 240).Engine oil level
More information on engine oil can be
found in the “Operation” section
(
page 235).
Opening hood (
page 234).
Coolant
For normal replenishing, use water (pota-
ble water quality). More information on
coolant can be found in the “Operation”
section (
page 238).
Vehicle lighting
Check function and cleanliness. For more
information on replacing light bulbs, see
the “Practical hints” section (
page 292).
Exterior lamp switch (
page 98).
Tire inflation pressure
More information on tire inflation pressure
can be found in the “Operation” section
(
page 242).
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: MY 2003
Mercedes-Benz C320 models, except
those equipped with manual transmis-
sion or 4MATIC*.
More information on Flexible Fuel Vehi-
cles can be found in the “Technical Da-
ta” section (
page 332).
iLeaving the engine running and the fuel
cap open can cause the
?
lamp to
illuminate.
See also “Practical hints” section
(
page 258).
S203 MY03_A.book Page 233 Tuesday, January 28, 2003 2:22 PM
Page 232 of 370

238 OperationEngine compartmentCoolant 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 the cap slowly approx-
imately one half turn to the left to re-
lease 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.
More information on coolant can be found
in the “Technical data” section
(
page 334).
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 display in-
dicates 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 approx-
imately ½ turn to relieve excess pres-
sure. If opened immediately, scalding
hot fluid and steam will be blown out un-
der pressure.
Do not spill antifreeze on hot engine
parts. Antifreeze contains ethylene gly-
col which may burn if it comes into con-
tact with hot engine parts.
S203 MY03_A.book Page 238 Tuesday, January 28, 2003 2:22 PM
Page 272 of 370

278 Practical hintsWhat to do if …Display
Possible cause
Suggested solution
#
UNDERVOLTAGE
ENGINE ON!
The battery has insufficient voltage and
can no longer supply the convenience
functions such as seat heater*.
Start the engine (
page 44).
UNDERVOLTAGE
SWITCH CONSUMERS OFF!
The battery is malfunctioning.
Have the battery checked at a ser-
vice station.
G
VISIT WORKSHOP!
DISPLAY DEFECTIVE
The instrument cluster display is mal-
functioning.
Continue driving with added cau-
tion.
Visit an authorized Mercedes-Benz
Center as soon as possible.
±
VISIT WORKSHOP!
DISPLAY DEFECTIVE
Certain electronic systems are unable to
relay information to the control system.
The following systems may have failed:
Coolant temperature display
Tachometer
Cruise control display
Have the electronic systems
checked by an authorized
Mercedes-Benz Center
(page 258).
W
WASHER FLUID
CHECK LEVEL!
The fluid level has dropped to about
1/3
of total reservoir capacity.
Add washer fluid (
page 240).
S203 MY03_A.book Page 278 Tuesday, January 28, 2003 2:22 PM
Page 330 of 370

336 Technical dataFuels, coolants, lubricants etc.Windshield and headlamp washer system
Both the windshield and headlamp washer
systems are supplied from the windshield
washer fluid reservoir.
The washer fluid reservoir has a capacity of
approx.
6.4 US qt (6.0 l) in vehicles with head-
lamp cleaning system*
3.2 US qt (3.0 l) in vehicles without
headlamp cleaning system
Refill the reservoir with MB Windshield
Washer Concentrate and water (or con-
centrate and commercially available
premixed windshield washer sol-
vent/antifreeze, depending on ambient
temperatures).Windshield and headlamp washer fluid
mixing ratio
For temperatures above freezing use
MB Windshield Washer Concentrate “S”
and water:
1 part “S” to 100 parts water
[40 ml “S” to 1 gallon (4 l) water].
For temperatures below freezing use
MB Windshield Washer Concentrate “S”
and commercially available premixed
windshield washer solvent/antifreeze:
1 part “S” to 100 parts solvent
[40 ml “S” to 1 gallon (4 l) solvent].
Warning!
G
Washer solvent/antifreeze is highly flamma-
ble. Do not spill washer solvent/antifreeze
on hot engine parts, because it may burn.
You can be seriously burned.
S203 MY03_A.book Page 336 Tuesday, January 28, 2003 2:22 PM