2008 MERCEDES-BENZ C300 Practical hints

377 Practical hints
What to do if …?
ProblemPossible cause/consequenceSuggested solution
;
(USA only)
3
(Canada only)
The red brake warning
lamp comes on while the
engine is running and an
acoustic warning sounds.You are driving with the parking brake set.Release the parking brake
(
page 130).
The red brake warning
lamp comes on while the
engine is running.There is insufficient brake fluid in the reser-
voir.Risk of accident!
Carefully stop the vehicle in a safe loca-
tion or as soon as it is safe to do so.
Depress the parking brake
(
page 134).
Contact an authorized Mercedes-Benz
Center.
Do not add brake fluid! This will not
solve the problem.
Warning!G
Driving with the brake warning lamp illumi-
nated can result in an accident. Have your
brake system checked immediately if the
brake warning lamp stays on.
Do not add brake fluid before checking the
brake system.
Overfilling the brake fluid reservoir can re-
sult 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.

378 Practical hints
What to do if …?
ProblemPossible cause/consequenceSuggested solution
±The yellow engine malfunc-
tion indicator lamp comes
on while driving.There is a malfunction in:

The fuel management system

The ignition system

The emission control system

Systems which affect emissions
Such malfunctions may result in excessive
emissions values and may switch the en-
gine to its limp-home (emergency opera-
tion) mode.
Have the vehicle checked as soon as
possible at an authorized
Mercedes-Benz Center.
An on-board diagnostic connector is
used by the service station to link the
vehicle to the shop diagnostics system.
It allows the accurate identification of
system malfunctions through the read-
out of diagnostic trouble codes. It is lo-
cated in the front left area of the
footwell next to the parking brake pedal.
iIn some states you may be required by law
to have the vehicle serviced as soon as the
engine malfunction indicator lamp comes on.
Check local requirements.

379 Practical hints
What to do if …?
ProblemPossible cause/consequenceSuggested solution
±The yellow engine malfunc-
tion indicator lamp comes
on while driving.A loss of pressure has been detected in the
fuel system. The fuel cap may not be closed
properly or the fuel system may be leaky.Check the fuel cap.
If it is not closed properly:
Close the fuel cap.
If it is closed properly:
Have the fuel system checked at an au-
thorized Mercedes-Benz Center.
vThe yellow ESP® warning
lamp comes on while the
engine is running.The ESP® has been switched off with the
ESP® switch or has been switched off due
to a malfunction.
Risk of accident!
When the ESP
® is switched off it will not
stabilize the vehicle if the system recogniz-
es that the vehicle starts to skid or that a
wheel is spinning.
The cruise control is deactivated and can-
not be switched on.
Switch the ESP® back on (page 64).
Exceptions: (
page 63).
If leaving the ESP® switched off, adapt
your speed and driving to the prevailing
road, weather and traffic conditions.
If the ESP
® cannot be switched on:
Continue driving with added caution.
Observer additional messages that may
appear in the multifunction display
(
page 389).
Have the system checked at an
authorized Mercedes-Benz Center as
soon as possible.

380 Practical hints
What to do if …?
ProblemPossible cause/consequenceSuggested solution
vThe yellow ESP® warning
lamp flashes while driving.The ESP® or traction system has come
into operation because of detected trac-
tion loss in at least one tire.
The cruise control is deactivated.When driving off, apply as little throttle as pos-
sible.
While driving, ease up on the accelerator.
Adapt your speed and driving to the prevailing
road, weather and traffic conditions.
Do not deactivate the ESP®.
Exceptions: (
page 63).
Failure to follow these instructions increases the
risk of an accident.
4The yellow fuel tank re-
serve warning lamp in the
fuel gauge comes on while
driving.The fuel level has gone below the reserve
mark.Refuel at the next gas station (page 322).
comes on for a maximum
of 6 seconds after starting
the engine.The seat belt telltale reminds you and your
passengers to fasten your seat belts be-
fore driving off.Fasten your seat belts.
Regardless of whether the seat belts are fas-
tened or not, the seat belt telltale always
comes on and remains lit for 6 seconds after
starting the engine.

381 Practical hints
What to do if …?
ProblemPossible cause/consequenceSuggested solution
a maximum of 6 seconds af-
ter starting the engine.You have forgotten to fasten your seat belt.Fasten your seat belt.
The warning chime stops sounding.
comes on while the vehicle is
standing still and the engine
is running or during driving.You and/or your front passenger have forgot-
ten to fasten your seat belts.Fasten your seat belts.
The seat belt telltale goes out.
There are items placed on the front passenger
seat and therefore the system senses the front
passenger seat as being occupied.Remove the items from the front pas-
senger seat and put them in a safe
place.
The seat belt telltale goes out.
belt telltale flashes and you
additionally hear an intermit-
tent warning chime with in-
creasing intensity.The vehicle’s speed has exceeded 15 mph
(25 km/h) and you and/or your front passen-
ger have forgotten to fasten your seat belts.Fasten your seat belts.
The seat belt telltale goes out and the
warning chime stops sounding.
There are items placed on the front passenger
seat and therefore the system senses the front
passenger seat as being occupied.Remove the items from the front pas-
senger seat and put them in a safe
place.
The seat belt telltale goes out and the
warning chime stops sounding.
iAfter 60 seconds with an unfastened seat
belt the warning chime stops sounding and the
seat belt telltale illuminates continuously. The seat belt telltale will only go out if both, the
driver’s and front passenger’s seat belt are fas-
tened, or the vehicle is standing still and a front door is
opened.

382 Practical hints
What to do if …?
ProblemPossible cause/consequenceSuggested solution
=The red SRS indicator lamp
comes on while driving.There is a malfunction in the supplemental
restraint systems. The air bags or Emergen-
cy Tensioning Devices (ETDs) could deploy
unexpectedly or fail to activate in an acci-
dent.Drive with added caution to the nearest
authorized Mercedes-Benz Center.
Warning!G
In the event a malfunction of the SRS is indi-
cated as outlined above, the SRS may not be
operational. For your safety, we strongly
recommend that you contact an authorized
Mercedes-Benz Center immediately to have
the system checked; otherwise the SRS may
not be deployed when needed in an acci-
dent, which could result in serious or fatal
injury, or it might deploy unexpectedly and
unnecessarily which could also result in an
accident and/or injury to you or to others.

383 Practical hints
What to do if …?
ProblemPossible cause/consequenceSuggested solution
HCombination low tire
pressure/TPMS malfunction
telltale for the TPMS illuminates
continuously.The TPMS detects a loss of pressure in at
least one tire.Carefully bring the vehicle to a halt,
avoiding abrupt steering and braking
maneuvers. Observe the traffic situation
around you.
Read and observe messages in the
multifunction display.
If the tire inflation pressure in the
respective tire(s) has (have) been correct-
ed, the combination low tire pres-
sure/TPMS malfunction telltale goes out
after few minutes driving.
HCombination low tire
pressure/TPMS malfunction
telltale for the TPMS flashes
60 seconds and then stays
illuminated.There is a malfunction in the TPMS.Read and observe messages in the
multifunction display.
Have the TPMS checked at an autho-
rized Mercedes-Benz Center.
After the malfunction has been remedied
the combination low tire pressure/TPMS
malfunction telltale goes out after few
minutes driving.

384 Practical hints
What to do if …?
Warning!G
Each tire, including the spare (if provided),
should be checked monthly when cold and
inflated to the inflation pressure recom-
mended by the vehicle manufacturer on the
Tire and Loading Information placard on the
driver’s door B-pillar (
page 334) or, if
available, the tire inflation pressure label on
the inside of the fuel filler flap (
page 322).
If your vehicle has tires of a different size
than the size indicated on the Tire and
Loading Information placard or the tire
inflation pressure label, you should deter-
mine the proper tire inflation pressure for
those tires.
As an added safety feature, your vehicle has
been equipped with a tire pressure monitor-
ing system (TPMS) that illuminates a low tire
pressure telltale when one or more of your
tires is significantly underinflated. Accord-
ingly, when the low tire pressure telltale illu-
minates, you should stop and check your
tires as soon as possible, and inflate them to
the proper pressure. Driving on a significant-
ly underinflated tire causes the tire to over-
heat and can lead to tire failure.
Underinflation also reduces fuel efficiency
and tire tread life, and may affect the vehi-
cle’s handling and stopping ability. Please
note that the TPMS is not a substitute for
proper tire maintenance, and it is the driv-
er’s responsibility to maintain correct tire
pressure, even if underinflation has not
reached the level to trigger illumination of
the TPMS low tire pressure telltale.Your vehicle has also been equipped with a
TPMS malfunction indicator to indicate
when the system is not operating properly.
The TPMS malfunction indicator is com-
bined with the low tire pressure telltale.
When the system detects a malfunction, the
telltale will flash for approximately 1 minute
and then remain continuously illuminated.
This sequence will continue upon subse-
quent vehicle start-ups as long as the mal-
function exists. When the malfunction
indicator is illuminated, the system may not
be able to detect or signal low tire pressure
as intended.
TPMS malfunctions may occur for a variety
of reasons, including the installation of
replacement or alternate tires or wheels on
the vehicle that prevent the TPMS from
functioning properly. Always check the
TPMS malfunction telltale after replacing
one or more tires or wheels on your vehicle
to ensure that the replacement or alternate
tires and wheels allow the TPMS to continue
to function properly.