2008 MERCEDES-BENZ C300 4MATIC Owner's Manual

80 Controls in detail
Locking and unlocking
Front doors
Pull on door handle2 on the respec-
tive front door to open door.
If door was locked, locking knob1 will
move up.
Rear doors
Pull up locking knob1 on the respec-
tive rear door to unlock door.
Pull on door handle2 on the respec-
tive rear door to open door.
Automatic central locking
The doors and the trunk automatically lock
when the ignition is switched on and the
wheels are turning at vehicle speeds of ap-
proximately 9 mph (15 km/h) or more. The
locking knobs in the doors move down.
You can open a locked door from the in-
side. Open door only when conditions are
safe to do so.
You could therefore lock yourself out when
the vehicle is pushed or towed, or it is on a
test stand.Automatic central locking
activating/deactivating
You can deactivate the automatic locking
using the control system (
page 173).
1Central unlocking switch
2Central locking switch
Activating: Press and hold central
locking switch2 until you hear a
chime.
Deactivating: Press and hold central
unlocking switch1 until you hear a
chime.

81 Controls in detail
Locking and unlocking
Locking and unlocking from the inside
You can lock or unlock the doors and the
trunk from the inside using the central
locking or unlocking switch. This can be
useful, for example, if you want to lock the
vehicle before starting to drive.
The fuel filler flap will not be locked or un-
locked with the central locking or unlock-
ing switch, respectively.1Central unlocking switch
2Central locking switch
Unlocking: Press central unlocking
switch1.
The vehicle unlocks.
Locking: Press central locking
switch2.
If the front passenger door is closed,
the vehicle locks.
Warning!G
When leaving the vehicle, always remove the
SmartKey or SmartKey with KEYLESS-GO*
from the starter switch, take it with you, and
lock the vehicle. Do not leave children unat-
tended in the vehicle, or with access to an
unlocked vehicle. A child’s unsupervised ac-
cess to a vehicle could result in an accident
and/or serious personal injury.
iYou can open a locked door from inside at
any time. Open door only when conditions are
safe to do so.
If the vehicle was previously locked with the cen-
tral locking switch:

and the SmartKey or SmartKey with
KEYLESS-GO* is set to factory settings, the
complete vehicle is unlocked when a door is
opened from the inside

and the SmartKey or SmartKey with
KEYLESS-GO* is set to selective settings,
only the door opened from the inside is un-
locked
If the vehicle was previously centrally locked
with the SmartKey or with KEYLESS-GO*, it will
not unlock using the central unlocking switch.

82 Controls in detail
Starter switch positions
SmartKey
Starter switch
0For removing SmartKey1Power supply for some electrical con-
sumers, such as seat adjustment
2Ignition (power supply for all electrical
consumers) and driving position.
All lamps (except high beam headlamp
indicator lamp and turn signal indicator
lamps unless activated) in the instru-
ment cluster come on. If a lamp in the
instrument cluster fails to come on
when the ignition is switched on, have
it checked and replaced if necessary.
If a lamp in the instrument cluster re-
mains on after starting the engine or
comes on while driving, refer to “Lamps
in instrument cluster” (
page 374).
3Starting position
For information on starting the engine us-
ing the SmartKey, see “Starting: Make sure
the gear selector lever is set to P.”
(
page 127).
Warning!G
When leaving the vehicle, always remove the
SmartKey or SmartKey with KEYLESS-GO*
from the starter switch, take it with you, and
lock the vehicle. Do not leave children unat-
tended in the vehicle, or with access to an
unlocked vehicle. A child’s unsupervised ac-
cess to a vehicle could result in an accident
and/or serious personal injury.
iWhen you switch on the ignition, the
indicator and warning lamps (except high beam
headlamp indicator lamp and turn signal indica-
tor lamps unless activated) in the instrument
cluster come on. The indicator and warning
lamps (except high beam headlamp indicator
lamp and turn signal indicator lamps if activated)
should go out when the engine is running. This in-
dicates that the respective systems are opera-
tional.
iVehicles with automatic transmission*: The
SmartKey can only be removed from the starter
switch with the gear selector lever in positionP.
iIf the SmartKey is left in starter switch
position0 for an extended period of time, it can
no longer be turned in the switch. In this case,
the steering is locked. To unlock, remove
SmartKey from starter switch and reinsert.
!If the SmartKey cannot be turned in the
starter switch, the battery may not be sufficient-
ly charged.

Check the battery and charge it if necessary
(
page 446).

Get a jump start (page 451).
To prevent accelerated battery discharge or a
completely discharged battery, always remove
the SmartKey from the starter switch when the
engine is not in operation.

83 Controls in detail
Starter switch positions
SmartKey with KEYLESS-GO*
(Canada only)
Vehicles equipped with the KEYLESS-GO
feature are supplied with a SmartKey with
integrated KEYLESS-GO function and a re-
movable KEYLESS-GO start/stop button.
With the KEYLESS-GO start/stop button
inserted and the SmartKey with
KEYLESS-GO present in the vehicle, press-
ing the KEYLESS-GO start/stop button

without the brake pedal depressed
corresponds to the various starter
switch positions (
page 84)

with the brake pedal firmly depressed
will start the engine (
page 128)If you wish or should there be a need to in-
sert the SmartKey with KEYLESS-GO in the
starter switch, the KEYLESS-GO start/stop
button can be easily removed by pulling it
out of the starter switch.
1KEYLESS-GO start/stop button
2Starter switch
Insert KEYLESS-GO start/stop
button1 into starter switch 2 (if not
inserted already).
iThe function of the SmartKey overrules the
KEYLESS-GO function.
iThe KEYLESS-GO start/stop button does
not need to be removed from the starter switch
when you leave the vehicle. However, always
take the SmartKey with KEYLESS-GO with you
when you leave the vehicle. As long as the
SmartKey with KEYLESS-GO is in the vehicle, the
vehicle’s electrical systems can be switched on
or the engine can be started using the
KEYLESS-GO start/stop button.
iWhen you switch from SmartKey mode back
to KEYLESS-GO mode, the system requires
2 seconds of detection time before you can use
the KEYLESS-GO button as usual.


84 Controls in detail
Starter switch positions
The SmartKey with KEYLESS-GO must be
located in the vehicle.
Make sure the gear selector lever is set
toP.
Do not depress the brake pedal.
1KEYLESS-GO start/stop button
(Canada only)
Position 0
Before you press the KEYLESS-GO
start/stop button, the vehicle’s on-board
electronics have status 0 (as with
SmartKey removed).Position 1
Press the KEYLESS-GO start/stop but-
ton once.
This supplies power for some electrical
consumers, such as seat adjustment.
Ignition (or position 2)
Press the KEYLESS-GO start/stop but-
ton twice.
This supplies power for all electrical
consumers.
All lamps (except high beam headlamp
indicator lamp and turn signal indicator
lamps unless activated) in the instru-
ment cluster come on. If a lamp in the
instrument cluster fails to come on
when the ignition is switched on, have
it checked and replaced if necessary. If a lamp in the instrument cluster re-
mains on after starting the engine or
comes on while driving, refer to “Lamps
in instrument cluster” (
page 374).
For information on starting the engine us-
ing the KEYLESS-GO start/stop button,
see “Starting: Make sure KEYLESS-GO
start/stop button is inserted in the starter
switch (e page 83).” (
page 128).
iIf you now press the KEYLESS-GO
start/stop button

once again, the ignition (position2) is
switched on

twice, the power supply is again switched off
iIf you now press the KEYLESS-GO
start/stop button once, the power supply is
again switched off.
iWhen you switch on the ignition, the indica-
tor and warning lamps (except high beam head-
lamp indicator lamp and turn signal indicator
lamps unless activated) in the instrument cluster
come on. The indicator and warning lamps (ex-
cept high beam headlamp indicator lamp and
turn signal indicator lamps if activated) should go
out when the engine is running. This indicates
that the respective systems are operational.


85 Controls in detail
Seats
Seats
Seat adjustment
Warning!G
All seat, head restraint adjustments, as well
as fastening of seat belts, must be done be-
fore the vehicle is put into motion.
Warning!G
Do not adjust the driver’s seat while driving.
Adjusting the seat while driving could cause
the driver to lose control of the vehicle.
Never ride in a moving vehicle with the seat
back in an excessively reclined position as
this can be dangerous. You could slide un-
der the seat belt in a collision. If you slide
under it, the seat belt would apply force at
the abdomen or neck. That could cause se-
rious or fatal injuries. The seat backrest and
seat belts provide the best restraint when
the wearer is in a position that is as upright
as possible and seat belts are properly posi-
tioned on the body.
Your seat must be adjusted so that you can
correctly fasten your seat belt.
Observe the following points:

Adjust the seat backrest until your arms
are slightly angled when holding the
steering wheel.

Adjust the seat to a comfortable seating
position that still allows you to reach the
accelerator/brake pedal safely. The po-
sition should be as far back as possible
with the driver still able to properly oper-
ate controls.

Adjust the head restraint so that it is as
close to the head as possible and the
center of the head restraint supports
the back of the head at eye level.

Never place hands under the seat or
near any moving parts while a seat is be-
ing adjusted.
Failure to do so could result in an accident
and/or serious personal injury.
Warning!G
When leaving the vehicle, always remove the
SmartKey or SmartKey with KEYLESS-GO*
from the starter switch, take it with you, and
lock the vehicle.
Even with the SmartKey or SmartKey with
KEYLESS-GO* (Canada only) removed from
the starter switch or the SmartKey with
KEYLESS-GO* (Canada only) removed from
the vehicle, the power seats can be
operated.
Therefore, do not leave children unattended
in the vehicle, or with access to an unlocked
vehicle. A child’s unsupervised access to a
vehicle could result in an accident and/or
serious personal injury.

86 Controls in detail
Seats
For additional information about children
in the vehicle, see “Children in the vehicle”
(
page 51).Power seat adjustment
The seat adjustment switch is located on
the entry side of each front seat base.
The seat adjustment switch for Canada ve-
hicles with memory function* are located
on the front doors.
1Seat cushion tilt
2Seat height
3Seat fore and aft
4Seat backrest tilt
Vehicles without memory function*:
Adjust the head restraint height manu-
ally (
page 87).
Driver’s door (Canada only)
1Seat cushion tilt
2Seat height
3Seat fore and aft
4Seat backrest tilt
5Head restraint height (
page 87)
Warning!G
According to accident statistics, children
are safer when properly restrained in the
rear seating positions than in the front seat-
ing position. Thus, we strongly recommend
that children be placed in the rear seats
whenever possible. Regardless of seating
position, children 12 years old and under
must be seated and properly secured in an
appropriately sized infant restraint, toddler
restraint, or booster seat recommended for
the size and weight of the child.
A child’s risk of serious or fatal injuries is
significantly increased if the child restraints
are not properly secured in the vehicle and
the child is not properly secured in the child
restraint.
iAfter unlocking the vehicle or turning off the
engine, the seat adjustment can be operated for
up to approximately 3 minutes with the
SmartKey or KEYLESS-GO* (Canada only) in
starter switch position0 or removed from the
starter switch.
Vehicles with memory function* (Canada only):
The memory function* is operational at any time.
Seat and steering wheel adjustment is always
possible.

87 Controls in detail
Seats
If it is not possible to adjust the seat with
the seat adjustment switch:
Insert the SmartKey or the
KEYLESS-GO start/stop button*
(Canada only) into the starter switch.
or
With SmartKey or KEYLESS-GO*
(Canada only) in starter switch
position0. Turn the SmartKey in
starter switch to position1 or press
the KEYLESS-GO start/stop button*
(Canada only) once.
or
Open the driver’s or front passenger
door.
Seat cushion tilt: Press the switch up
or down in the direction of
arrow1until your upper legs are
lightly supported.
Seat height: Press the switch up or
down in the direction of arrow2.
Seat fore and aft: Press the switch for-
ward or backward in the direction of
arrow3.
Seat backrest tilt: Press the switch
forward or backward in the direction of
arrow4.Adjusting front seat head restraints
You cannot remove the active head re-
straint on the driver’s and front passen-
ger’s seat.
For removal contact an authorized
Mercedes-Benz Center.
For information on active head restraints,
see “Active head restraints” (
page 50).
iCanada only:
The memory function* (
page 102) lets you
store the settings for the seat positions together
with the settings for the steering wheel and the
exterior rear view mirrors.
!When moving the seat, make sure there are
no items in the footwell or behind the seats. Oth-
erwise you could damage the seats.
Warning!G
For your protection, drive only with properly
positioned head restraints.
Adjust the head restraint so that it is as
close to the head as possible and the center
of the head restraint supports the back of
the head at eye level. This will reduce the po-
tential for injury to the head and neck in the
event of an accident or similar situation.
Do not drive the vehicle without the seat
head restraints. Head restraints are intend-
ed to help reduce injuries during an acci-
dent.