2008 MERCEDES-BENZ C300 Practical hints

385 Practical hints
What to do if …?
Air bag off indicator lamp
ProblemPossible cause/consequenceSuggested solution
5/The front passenger front air bag off in-
dicator lamp illuminates and remains il-
luminated with the weight of a typical
adult or someone larger than a small in-
dividual on the front passenger seat.The system is malfunctioning.Have the system checked as soon as
possible at an authorized
Mercedes-Benz Center.
Also read and observe any messages in
the multifunction display and follow
corrective steps (
page 387).
Warning!G
If the5/ and remains illuminated
with the weight of a typical adult or some-
one larger than a small individual on the
front passenger seat, do not have any pas-
senger use the front passenger seat until
the system has been repaired.

386 Practical hints
What to do if …?
ProblemPossible cause/consequenceSuggested solution
5/The front passenger front air
bag off indicator lamp does
not illuminate and/or does
not remain illuminated with
the weight of a typical
12-month-old child in a stan-
dard child restraint or less on
the front passenger seat.The system is malfunctioning.Make sure there is nothing between seat cushion
and child seat and check installation of the child
seat.
Make sure no objects applying supplemental
weight onto the seat are present.
If the front passenger front air bag off indicator
lamp remains out, have the system checked as
soon as possible at an authorized Mercedes-Benz
Center. Do not transport a child on the front pas-
senger seat until the system has been repaired.
Also read and observe any messages in the
multifunction display and follow corrective steps
(
page 387).
Warning!G
If the5/indicator lamp does not il-
luminate or remains out with the weight of a
typical 12-month-old child in a standard
child restraint or less on the front passenger
seat, do not transport a child on the front
passenger seat until the system has been
repaired.

387 Practical hints
What to do if …?
Vehicle status messages in the multi-
function display
Warning and malfunction messages ap-
pear in the multifunction display located in
the instrument cluster.
Certain warning and malfunction messag-
es are accompanied by an audible signal.
High-priority messages are shown in red
on the multifunction display. Messages of
lower priority are also shown in yellow or
white.
Address these messages accordingly and
follow the additional instructions given in
this Operator’s Manual.Certain messages of high priority cannot
be cleared from the multifunction display
using# or L on the multifunction
steering wheel (
page 152).
Other messages of high priority and mes-
sages of less immediate priority can be
cleared from the multifunction display
using# or L. They are then stored
in the vehicle status message memory
(
page 164). Remember that clearing a
message will only make the message dis-
appear. Clearing a message will not cor-
rect the condition that caused the
message to appear.
Warning!G
No messages will be displayed if either the
instrument cluster or the multifunction dis-
play is inoperative.
As a result, you will not be able to see infor-
mation about your driving conditions, such
as speed or outside temperature, warn-
ing/indicator lamps, malfunction/warning
messages or the failure of any systems.
Driving characteristics may be impaired.
If you must continue to drive, please do so
with added caution. Contact an authorized
Mercedes-Benz Center as soon as possible.

388 Practical hints
What to do if …?
On the pages that follow, you will find a
compilation of the most important warning
and malfunction messages that may ap-
pear in the malfunction display.
For your convenience the messages are di-
vided into two sections:

Text messages (page 389)

Symbol messages (page 397)
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 condition noted may cause
damage not covered by the Mercedes-Benz
Limited Warranty, or result in property dam-
age or personal injury.
iSwitching on the ignition causes all instru-
ment cluster lamps (except high beam headlamp
indicator lamp and turn signal indicator lamps
unless activated) as well as the multifunction dis-
play to come on. Make sure the lamps and multi-
function display are in working order before
starting your journey.

389 Practical hints
What to do if …?
Text messages
Display Possible cause/consequencePossible solution
ABS and ESP
Currently Unavailable
See Operator’s ManualABS and ESP® are not available due to a malfunction.
BAS and the hill start assist are also switched off. It
is possible that the self-diagnostics have not yet
been completed.
The brake system still functions normally.Drive a short distance with gentle turns above a
speed of 12 mph (20 km/h).
The message disappears when ABS and ESP
®
are again available.
The ABS and ESP® were deactivated because of in-
sufficient power supply. The charging voltage has
fallen below 10 volts. BAS and the hill start assist are
also deactivated.
The brake system still functions normally but without
the ABS and ESP
® available.
When the voltage is above this value again, the ABS
and ESP® are operational again and the message in
the multifunction display should disappear.
If the message in the multifunction display does not
disappear:
Have the generator (alternator) and the battery
checked.
ABS and ESP
Inoperative
See Operator’s ManualABS and ESP® are switched off due to a malfunction.
BAS and the hill start assist are also switched off.
The brake system still functions normally but without
the ABS and ESP
® available.
Continue driving with added caution. Wheels
may lock during hard braking, reducing steering
capability.
Have the system checked at an authorized
Mercedes-Benz Center as soon as possible.
Failure to follow these instructions increases the
risk of an accident.

390 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Cruise control
- - - mph
(USA only)
You have tried to switch on cruise control
below a speed of 20 mph (30 km/h).If traffic conditions allow, drive faster than 20 mph (30 km/h)
and save the speed.
Cruise control
- - - km/h
(Canada only)
The automatic transmission* is in position
P, R or N.Move the gear selector lever to positionD (page 140).
ESP® is switched off.Switch on ESP® (page 64).
The system is overheated.Wait until the system cools down.
Cruise Control and
Speedtronic
InoperativeCruise control is malfunctioning. In addition
a warning chime sounds.Have the cruise control checked at an authorized
Mercedes-Benz Center.
Check,
Tire Pressure
Then Restart
Run Flat Indicator
(Canada only)
There was a warning message about a loss
in tire inflation pressure and the Run Flat In-
dicator has not been restarted yet.Make sure the correct tire inflation pressure is set for each
tire (
page 339).
Then restart the Run Flat Indicator (page 343).
Run Flat
Indicator
Inoperative
(Canada only)
Run Flat Indicator is malfunctioning.Have the Run Flat Indicator checked at an authorized
Mercedes-Benz Center.

391 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Check
Tire Pressure Soon
(Canada only)
The Run Flat Indicator indicates that the
pressure is too low in one or more tires.Carefully bring the vehicle to a halt, avoiding abrupt steering
and braking maneuvers. Observe the traffic situation around
you.
Check and adjust the tire inflation pressure as required
(
page 339).
If necessary, change the wheel (page 440).
Restart the Run Flat Indicator after adjusting the tire inflation
pressure values (
page 343).
Warning!G
Do not drive with a flat tire. A flat tire affects
the ability to steer or brake the vehicle. You
may lose control of the vehicle. Continued
driving with a flat tire will cause excessive
heat build-up and possibly a fire.

392 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Shift
to PYou have turned off the engine with the
KEYLESS-GO* start/stop button (Canada only) in
gear selector lever positionN and opened the driv-
er’s door.
or
You have attempted to switch off the engine with the
KEYLESS-GO* start/stop button (Canada only) while
the gear selector lever was in positionR orD.Place the gear selector lever in positionP.
Shift to P or N
To Start EngineYou have attempted to start the engine while the au-
tomatic transmission* was set to position R or D.Move the gear selector lever to position P or N
(
page 140).
Tire Press. Monitor
Inoperative
(USA only)
The TPMS is malfunctioning.Have the TPMS checked at an authorized
Mercedes-Benz Center.
Wheel Sensors Error
Tire Pressure Monitor
Inoperative
(USA only)
There are wheels without appropriate wheel sensors
mounted (e.g. winter tires).Have the TPMS checked at an authorized
Mercedes-Benz Center.
Have the wheel sensors installed at an autho-
rized Mercedes-Benz Center.
Tire Press. Monitor
Currently Unavailable
(USA only)
The TPMS is unable to monitor the tire pressure due
to a nearby radio interference source.As soon as the causes of the malfunction have
been removed, the TPMS automatically be-
comes active again after a few minutes driving.