check engine MERCEDES-BENZ C240 4MATIC 2004 W203 Owner's Guide

278 Practical hintsWhat to do if …Problem
Possible cause
Suggested solution
The yellow fuel tank reserve warning lamp comes
on while driving.
The fuel level has gone below the reserve
mark.

Refuel at the next gas station
(page 249).
<
The red seat belt non-usage warning
lamp illuminates for a brief period
after starting the engine.
The warning lamp reminds you to fasten
seat belts.

Fasten your seat belt.
1
The red SRS indicator lamp comes on
while driving.
There is a malfunction in the restraint sys-
tems. The airbags or emergency tensioning
device (ETDs) could deploy unexpectedly
or fail to activate in an accident.

Drive with added caution to the
nearest authorized Mercedes-Benz
Center.
Warning!
G
In the event a malfunction of the SRS is
indicated as outlined above, the SRS may
not be operational. For your safety, we
strongly recommend that you visit an autho-
rized Mercedes-Benz Center immediately to
have the system checked; otherwise the
SRS may not be activated when needed in
an accident, which could result in serious or
fatal injury, or it might deploy unexpectedly
and unnecessarily which could result in an
accident and/or injury to you or to others.

285 Practical hints
What to do if …
Display symbol
Display message
Possible cause
Possible 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
inoperative water pump which may
result in damage to the engine. Notify
an authorized Mercedes-Benz Center.
If it is intact:

Drive immediately to the nearest
authorized Mercedes-Benz Center.
UNDERVOLTAGE
ENGINE ON!
The battery has insufficient voltage and
can no longer supply the convenience
functions such as seat heater*.

Start the engine (
page 43).
UNDERVOLTAGE
SWITCH CONSUMERS OFF!
The battery is malfunctioning.

Have the battery checked at a service
station.

286 Practical hintsWhat to do if …Display symbol
Display message
Possible cause
Possible solution
!
(Canada only)
;
(USA only)
PARK. BRAKE
RELEASE BRAKE!
You are driving with the parking brake
set.

Release the parking brake
(page 45).
2
BRAKE WEAR
VISIT WORKSHOP!
The brake pads have reached their wear
limit.

Have the brake pads replaced as soon
as possible.
3
BRAKE FLUID
VISIT WORKSHOP!
There is insufficient brake fluid in the
reservoir.

Risk of accident! Stop the vehicle and
notify an authorized Mercedes-Benz
Center. Do not add brake fluid! This
will not solve the problem.
Warning!
G
Driving with this message displayed can
result in an accident. Have your brake
system checked immediately. Do not add
brake fluid before checking the brake
system. Overfilling the brake fluid reservoir
can result in spilling brake fluid on hot
engine parts and the brake fluid catching
fire. You can be seriously burned.
!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.
!Brake pad thickness must be visually
checked by a qualified technician at the
intervals specified in the Service
booklet.

287 Practical hints
What to do if …
Display symbol
Display message
Possible cause
Possible solution
B
COOLANT
CHECK LEVEL!
The coolant level is too low.

Add coolant (
page 257).

If you have to add coolant frequently,
have the cooling system checked by
an authorized 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 can 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 Limited
Warranty.
Do not drive without sufficient amount
of coolant in the cooling system. The
engine will overheat causing major
engine damage.

289 Practical hints
What to do if …
Display symbol
Display message
Possible cause
Possible solution
Ï
COOLANT
STOP, ENGINE OFF!
The poly-V-belt could be broken.

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
inoperative water pump which may
result in damage to the engine. Notify
an authorized Mercedes-Benz Center.
If it is intact:

Do not continue to drive the vehicle
with this message displayed. Doing so
could result in serious engine damage
that is not covered by the
Mercedes-Benz Limited Warranty.
COOLANT
VISIT WORKSHOP!
The cooling fan for the coolant is
malfunctioning.

Observe the coolant temperature
display.

Have the fan replaced as soon as
possible.

291 Practical hints
What to do if …
Display symbol
Display messages
Possible cause
Suggested solution
:
USA only:ADD 1.0 Qt. ENGINE OIL
WHEN NEXT REFUELING!Canada only:ADD 1.0 LITER ENG. OIL
WHEN NEXT REFUELING!
The engine oil level is too low.

Add engine oil (
page 255) and check
the engine oil level (
page 254).
ENGINE OIL LEVEL
STOP, ENGINE OFF!
There is no oil in the engine. There is a
danger of engine damage.

Carefully bring the vehicle to a halt as
soon as possible.

Turn off the engine.

Add engine oil (
page 255) and check
the engine oil level (
page 254).
ENGINE OIL LEVEL
REDUCE OIL LEVEL
You have added too much engine oil.
There is a risk of damaging the engine or
the catalytic converter.

Have oil siphoned or drained off.
Observe all legal requirements with
respect to its disposal.
ENGINE OIL
VISIT WORKSHOP!
It may be that there is water in the engine
oil.

Have the engine oil checked.

292 Practical hintsWhat to do if …When the message
ADD 1.0 Qt. ENGINE
OIL WHEN NEXT REFUELING!
(Canada:
1.0 LITER
) appears while the engine is
running and at operating temperature, the
engine oil level has dropped to
approximately 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, drive to the nearest
service station where the engine oil should
be topped to the required level with an
approved oil.
Display symbol
Display messages
Possible cause
Suggested solution
:
ENGINE OIL LEVEL
VISIT WORKSHOP!
The engine oil has dropped to a critical
level.

Check the engine oil level
(page 254) and add oil as required
(page 255).

If you must add engine oil frequently,
have the engine checked for possible
leaks.
ENGINE OIL SENSOR
VISIT WORKSHOP!
The measuring system is malfunctioning.

Have the measuring system checked
by an authorized Mercedes-Benz
Center.!The engine oil level warnings should
not be ignored. Extended driving with
the symbol displayed could result in
serious engine damage that is not
covered by the Mercedes-Benz Limited
Warranty.

323 Practical hints
Battery
Battery
The battery is located in the engine
compartment on the right hand side.
Removal of filter box:
Release the three clamps1.

Remove filter box.
Installation of filter box:

Insert filter box properly.

Secure it with the three clamps1.
Warning!
G
Failure to follow these instructions can
result in severe injury or death.
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 termi-
nal clamps while the engine is running
or the SmartKey is in the starter switch.
Otherwise the alternator and other
electronic components could be se-
verely damaged.
Have the battery checked regularly by
an authorized Mercedes-Benz Center.
Refer to Service Booklet for mainte-
nance intervals or contact your autho-
rized 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 battery only to avoid the risk
of acid burns in the event of an accident.

326 Practical hintsJump 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 con-
verter are cold.


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


Only jump start from batteries with the
same voltage rating (12 V). Jump
starting with a more powerful battery
could damage the vehicle’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 oth-
er 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.
!Jump starting may only be performed
on the battery installed in the engine
compartment.
Avoid repeated and lengthy starting
attempts.
Do not attempt to start the engine
using a battery 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 catalytic 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 attached to a battery.

327 Practical hints
Jump starting
The battery is located in the engine
compartment on the right hand side. The
terminals for jump starting are located in
front of the battery.
Make sure the two vehicles do not
touch.

Turn off all electrical consumers.

Apply parking brake.

Shift gear selector lever to positionP
(manual transmission to Neutral).1Positive terminal of charged battery
2Positive under hood terminal in front of
discharged battery
3Negative terminal of charged battery
4Negative under hood terminal in front
of discharged battery

Connect positive terminal1 of the
charged battery with positive under
hood terminal2 in front of the
discharged battery with the jumper
cables. Clamp cable to charged
battery1 first.

Start engine of the vehicle with the
charged battery and run at idle speed.

Connect negative terminal3 of the
charged battery with negative under
hood terminal4 of the discharged
battery with the jumper cables. Clamp
cable to charged battery3 first.

Start the engine of the disabled
vehicle.
You can now again turn on the electrical
consumers. Do not turn on the lights under
any circumstances.

Remove the jumper cables first from
negative terminals3 and4 and then
from positive terminals1 and2.
You can now turn on the lights.

Have the battery checked at the near-
est authorized Mercedes-Benz Center.
Warning!
G
Keep flames or sparks away from battery.
Do not smoke.
Observe all safety instructions and precau-
tions when handling automotive batteries
(page 258).
!Vehicles with automatic transmission
and/or 4MATIC:
Do not tow-start the vehicle.