MERCEDES-BENZ C300 4MATIC 2008 W204 Owner's Manual

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.

393 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Front Passenger
Airbag Disabled
See Operator’s Manu-
alFront passenger front air bag is
deactivated while driving even
though an adult or someone
larger than a small individual is
occupying the front passenger
seat. Forces acting on the seat
may make the system sense a
decrease in weight.Stop the vehicle in a safe location as soon as possible and check the front
passenger seat for the following:
Switch off the ignition (page 82).
Have the front passenger vacate the seat and exit the vehicle.
Keep the seat unoccupied, close the front passenger door and switch
on the ignition (
page 82).
Monitor the
5/indicator lamp right of the instrument cluster
(
page 45) and the multifunction display in the instrument cluster
(
page 151) for the following:
(Continued on next page)

394 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Front Passenger
Airbag Disabled
See Operator’s Manu-
alWith the seat unoccupied and the ignition switched on (page 82),

the 5/indicator lamp right of the instrument cluster should il-
luminate and remain illuminated, indicating that the OCS (
page 41)
has deactivated the air bag.

the message Front Passenger Airbag Enabled See Operator’s Man-
ual
or the message Front Passenger Airbag Disabled See Opera-
tor’s Manual
should not appear in the multifunction display at any time
the seat is unoccupied. Wait at least 60 seconds for the system to com-
plete the necessary check cycles and to make sure neither message ap-
pears in the multifunction display.
If above conditions are met, you can occupy the front passenger seat again.
Depending on the front passenger classification sensed by the OCS
(
page 41), the5/indicator lamp will remain illuminated or go
out.
If above conditions are not met, the system is not working properly. Have
the system checked as soon as possible at an authorized Mercedes-Benz
Center.
Warning!G
If the 5/indicator lamp remains
illuminated with an adult occupant on the
front passenger seat even after performing
the above corrective steps, do not have any
passenger use the front passenger seat until
the system has been repaired.

395 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Front Passenger
Airbag Enabled
See Operator’s Manu-
alFront passenger front air bag is
activated while driving even
though a child, small individual,
or object below the system’s
weight threshold is on the front
passenger seat, or the front pas-
senger seat is empty. Objects
on the seat or forces acting on
the seat may make the system
sense supplemental weight.Stop the vehicle in a safe location as soon as possible and check the front
passenger seat for the following:
Switch off the ignition (page 82).
Remove child and child restraint from front passenger seat and properly
secure the child in rear seat employing the child restraint if necessary.
Make sure no objects which apply forces to the seat are present (e.g.
objects such as books, briefcases etc. lodged behind or around the
seat, head restraints pushing against roof, etc.). The system may recog-
nize such forces as supplemental weight and sense that an occupant on
the front passenger seat is of a greater weight than actually present.
Keep the seat unoccupied, close the front passenger door and switch
on the ignition (
page 82).
Monitor the
5/indicator lamp right of the instrument cluster
(
page 45) and the multifunction display in the instrument cluster
(
page 151) for the following:
(Continued on next page)

396 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
Front Passenger
Airbag Enabled
See Operator’s Manu-
alWith the seat unoccupied and the ignition switched on (page 82),

the 5/indicator lamp right of the instrument cluster should il-
luminate and remain illuminated, indicating that the OCS (
page 41)
has deactivated the air bag.

the message Front Passenger Airbag Enabled See Operator’s Man-
ual
or the message Front Passenger Airbag Disabled See Opera-
tor’s Manual
should not appear in the multifunction display at any time
the seat is unoccupied. Wait at least 60 seconds for the system to com-
plete the necessary check cycles and to make sure neither message ap-
pears in the multifunction display.
If above conditions are met, you can occupy the front passenger seat again.
Depending on the front passenger classification sensed by the OCS
(
page 41), the 5/indicator lamp will remain illuminated or go
out.
If above conditions are not met, the system is not working properly. Have
the system checked as soon as possible at an authorized Mercedes-Benz
Center.
Warning!G
If the 5/indicator lamp remains
illuminated with an adult occupant on the
front passenger seat even after performing
the above corrective steps, do not have any
passenger use the front passenger seat until
the system has been repaired.

397 Practical hints
What to do if …?
Symbol 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 complet-
ed.
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 be-
cause of insufficient power supply. The
charging voltage has fallen below 10 volts.
BAS and the hill start assist are also deacti-
vated.
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.

398 Practical hints
What to do if …?
-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 is still functioning nor-
mally but without the ABS available.Continue driving with added caution.
Wheels may lock during hard braking, re-
ducing steering capability.
Have the system checked at an authorized
Mercedes-Benz Center as soon as possi-
ble.
Failure to follow these instructions increases
the risk of an accident.
Display Possible cause/consequencePossible solution

399 Practical hints
What to do if …?
Display Possible cause/consequencePossible solution
#The battery is no longer charging.
Possible causes:

alternator malfunctioning

broken poly-V-belt
Stop the vehicle immediately in a safe loca-
tion and check the poly-V-belt.
If it is broken:
Do not continue to drive. Otherwise the en-
gine will overheat due to an inoperative water
pump which may result in damage to the en-
gine.
Notify an authorized Mercedes-Benz Center.
If it is intact:
Drive immediately to the nearest authorized
Mercedes-Benz Center.
There is a malfunction in the electronic sys-
tem.Have the system checked at an authorized
Mercedes-Benz Center as soon as possible.
2Check
Brake Pad WearThe brake pads have reached their wear
limit.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 Maintenance Booklet.