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 240 of 370

246 OperationMaintenance
MaintenanceWe strongly recommend that you have
your vehicle serviced by your authorized
Mercedes-Benz Center, in accordance with
the Service Booklet at the times called for
by the FSS (Flexible Service System).
Failure to have the vehicle maintained in
accordance with the Service Booklet at the
designated times /mileage called for by
the FSS may result in vehicle damage not
covered by the Mercedes-Benz Limited
Warranty.
FSS will notify you when your next service
is due.
Approximately one month before your next
service is due, one of the following mes-
sages will appear in the multifunction dis-
play while you are driving or when you
switch on the ignition (example service A):SERVICE A IN XX DAYS
SERVICE A IN XX MILES (KM)
SERVICE A DUE NOW!
The type of service due is indicated in the
speedometer display field:9
Minor service (A)
½
Major service (B)
Clearing the service indicator
The service indicator is automatically
cleared
after 10 seconds when you switch on
the ignition or when reaching the ser-
vice threshold while driving
after 30 seconds, once the suggested
service term has passed
You can also clear it yourself.
Press the reset knob on the instrument
cluster (
page 22).
Service term exceeded
If you have exceeded the suggested ser-
vice term, you will see the following mes-
sage in the multifunction display:SERVICE A EXCEEDED BY XX DAYS
SERVICE A EXCEEDED BY XX MILES (KM)The Mercedes-Benz Center will reset the
service indicator following a completed
service.
iThe interval between services depends
on your driving habits. A gentle driving
style, moderate engine speeds and the
avoidance of short distance trips will
lengthen the interval between services.
S203 MY03_A.book Page 246 Tuesday, January 28, 2003 2:22 PM
Page 241 of 370

247 Operation
Maintenance
Calling up the service indicator
Switch ignition on.
The standard display of the control sys-
tem appears (
page 112).
Press button
k
or
j
on the mul-
tifunction steering wheel until the FSS
indicator appears in the multifunction
display.
Resetting the service indicator
In the event that the service on your vehi-
cle is not carried out by an authorized
Mercedes-Benz Center, you can reset the
service indicator yourself.
Switch ignition on.
The standard display of the control sys-
tem appears (
page 112).
Press button
k
or
j
on the mul-
tifunction steering wheel until the FSS
indicator appears in the multifunction
display.
Press the reset knob for about four
seconds.
This message appears in the tachome-
ter:DO YOU WANT TO RESET SERVICE INTER-
VAL? CONFIRM BY PRESSING RESET (R)
BUTTON
To confirm, hold down the reset knob
until you hear a signal.The service indicator now displays the
reset interval.
iIf the battery is disconnected, the days
of disconnection will not be included in
the count shown by the service indica-
tor. To arrive at the true service dead-
line, you will need to subtract these
days from the days shown in the ser-
vice indicator.
Do not confuse the service indicator
with the engine oil level indicator
:
.
iIf the service indicator was inadvertent-
ly reset, have a Mercedes-Benz Center
correct it.
Only reset if the proper service has
been performed. Resetting the system
without performing the proper service
as called for by the FSS will cause the
FSS to incorrectly determine the next
service interval which will result in en-
gine damage not covered by the
Mercedes-Benz Limited Warranty.
S203 MY03_A.book Page 247 Tuesday, January 28, 2003 2:22 PM
Page 249 of 370
255 Practical hints
What to do if …
Problem
Possible cause
Suggested solution
-
The yellow ABS malfunction indi-
cator lamp comes on while driv-
ing.
The ABS has detected a malfunction and has
switched off. The BAS and the ESP are also
switched off (see messages in display).
The brake system is still functioning normally
but without the ABS available.
Continue driving with added caution.
Wheels may lock during hard braking
reducing steering capability.
Have the system checked at an autho-
rized Mercedes-Benz Center as soon
as possible.
Failure to follow these instructions in-
creases the risk of an accident.
The charging voltage has fallen below
10 volts and the ABS has switched off.
When the voltage is above this value
again, the ABS is operational again.
If necessary, have the generator and
battery checked.
S203 MY03_A.book Page 255 Tuesday, January 28, 2003 2:22 PM
Page 254 of 370

260 Practical hintsWhat to do if …Messages in the display
The control system shows warning and
malfunction messages in the multifunction
display.
Certain warning and malfunction messag-
es are accompanied by an audible signal.
Address these messages accordingly and
follow the additional instructions given in
this Operator’s Manual.
Selecting the malfunction memory menu in
the control system (
page 115) displays
both cleared and uncleared messages.
High-priority messages appear in the mul-
tifunction display in red color.
Certain messages of high priority cannot
be cleared from the multifunction display
using the reset knob on the instrument
cluster.
Other messages of high priority and mes-
sages of less immediate priority (regular
display colors) can be cleared from the multifunction display using the reset knob
(
page 22) and are then stored in the mal-
function message memory (
page 115).
On the pages that follow, you will find a
compilation of all the messages that may
appear in the display. High priority mes-
sages appear on a red background.
Warning!
G
All categories of messages contain impor-
tant information which should be taken note
of and, where a malfunction is indicated, ad-
dressed as soon as possible at an autho-
rized Mercedes-Benz Center.
Failure to repair the condition noted may
cause damage not covered by the
Mercedes-Benz Limited Warranty, or result
in property damage or personal injury.Warning!
G
No messages will be displayed if either the
instrument cluster or the multifunction dis-
play is inoperative.
Contact your nearest authorized
Mercedes-Benz Center.
iTurning the key in starter switch to
position2 causes all lamps as well as
the multifunction display to come on.
Ensure that they are all in working or-
der before starting your journey.
S203 MY03_A.book Page 260 Tuesday, January 28, 2003 2:22 PM
Page 255 of 370
261 Practical hints
What to do if …
Display
Possible cause
Suggested solution
-
ABS SYSTEM
VISIT WORKSHOP!
The ABS has detected a malfunction and
has switched off. The ESP and the BAS
are also deactivated. The brake system is
still functioning normally but without the
ABS available.
Continue driving with added cau-
tion. Wheels will lock in hard brak-
ing reducing steering capability.
Have the system checked at an au-
thorized Mercedes-Benz Center as
soon as possible.
Failure to follow these instructions in-
creases the risk of accident.
DISPLAY DEFECTIVE
VISIT WORKSHOP!
The ABS or the ABS display is malfunc-
tioning.
Continue driving with added cau-
tion. Wheels will lock in hard brak-
ing reducing steering capability.
Have the system checked at an au-
thorized Mercedes-Benz Center as
soon as possible.
Failure to follow these instructions in-
creases the risk of accident.
S203 MY03_A.book Page 261 Tuesday, January 28, 2003 2:22 PM
Page 256 of 370

262 Practical hintsWhat to do if …Display
Possible cause
Suggested solution
BAS
BRAKE ASSIST
NOT AVAILABLE!
The charging voltage has fallen below
10 volts and the BAS has switched off.
When the voltage is above this val-
ue again, the BAS is operational
again.
If necessary, have the generator
and battery checked.
BRAKE ASSIST
VISIT WORKSHOP!
The BAS has detected a malfunction and
switched off. The brake system is still
functioning normally but without the BAS
available.
Continue driving with added cau-
tion.
Have the system checked at an au-
thorized Mercedes-Benz Center as
soon as possible.
Failure to follow these instructions in-
creases the risk of accident.
DISPLAY DEFECTIVE
VISIT WORKSHOP!
The BAS or the BAS display is malfunc-
tioning.
Continue driving with added cau-
tion.
Have the system checked at an au-
thorized Mercedes-Benz Center as
soon as possible.
Failure to follow these instructions in-
creases the risk of accident.
S203 MY03_A.book Page 262 Tuesday, January 28, 2003 2:22 PM
Page 257 of 370

263 Practical hints
What to do if …
Display
Possible cause
Suggested solution
#
BATTERY/ALTERNATOR
VISIT WORKSHOP!
The battery was charged with a battery
charger or jump started.
Have the battery checked at a service
station.
The battery is no longer charging.
Possible causes:
alternator malfunctioning
broken poly-V-belt
Stop immediately and check the
poly-V-belt.
If it is broken:
Do not continue to drive. Otherwise
the engine will overheat due to an in-
operative water pump which may re-
sult in damage to the engine. Notify an
authorized Mercedes-Benz Center.
If it is intact:
Drive immediately to the nearest au-
thorized Mercedes-Benz Center.
3
(Canada only)
;
(USA only)
BRAKE PAD WEAR
VISIT WORKSHOP!
The brake pads have reached their wear lim-
it.
Have the brake pads replaced as soon
as possible.
!Brake pad thickness must be visually
checked by a qualified technician at the
intervals specified in the Service book-
let.
S203 MY03_A.book Page 263 Tuesday, January 28, 2003 2:22 PM