MERCEDES-BENZ R320 2008 W251 Service Manual

40 Getting started
Unlocking
SmartKey
Starter switch
0For removing SmartKey
1Power supply for some electrical
consumers, 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 remains on after starting the engine or
comes on while driving, refer to “Lamps
in instrument cluster” (
page 414).
3Starting position
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)
will go out when the engine is running.
This indicates that the respective systems are
operational.
iIf the SmartKey does not belong to the
vehicle, the SmartKey can be turned in the
starter switch. However, the ignition does not
switch on and the engine does not start.
iWhen the SmartKey is removed from the
starter switch and the automatic transmission is
in a position other thanP, the automatic
transmission automatically shifts toP.
!If the SmartKey cannot be turned in
the starter switch, the battery may not be
sufficiently charged.

Check the battery and charge it if necessary
(
page 503).

Get a jump start (page 511).
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.

41 Getting started
Unlocking
SmartKey with KEYLESS-GO*
Vehicles equipped with the KEYLESS-GO
feature are supplied with a SmartKey with
integrated KEYLESS-GO function and a
removable 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 42)

with the brake pedal firmly depressed
will start the engine (
page 54)
If you wish or should there be a need to
insert 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
KEYLESS-GO start/stop button
3USA only
4Canada only
The SmartKey with KEYLESS-GO must be
located in the vehicle.
Insert KEYLESS-GO start/stop
button1 into starter switch 2 (if not
inserted already).
Make sure the automatic transmission
is set toP.
Do not depress the brake pedal.
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.

42 Getting started
Unlocking
Position 0
Before you press the KEYLESS-GO
start/stop button, the vehicle’s on-board
electronics have status0 (as with
SmartKey removed).
Position 1
Press the KEYLESS-GO start/stop
button once.
This supplies power for some electrical
consumers, such as seat adjustment.Ignition (or Position 2)
Press the KEYLESS-GO start/stop
button 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
remains on after starting the engine or
comes on while driving, refer to “Lamps
in instrument cluster” (
page 414).For information on starting the engine
using the KEYLESS-GO start/stop button,
see “Starting with KEYLESS-GO*”
(
page 54).
For more information on KEYLESS-GO, see
“SmartKey with KEYLESS-GO*”
(
page 113).
iIf you now press the KEYLESS-GO
start/stop button

once more, the ignition (position2) is
switched on

twice more, the power supply is again
switched off
iIf you now press the KEYLESS-GO
start/stop button once more, the power supply
is again switched off.
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)
will go out when the engine is running.
This indicates that the respective systems are
operational.

43 Getting started
Adjusting
Adjusting
Seats
Warning!G
All seat, head restraint, steering wheel, and
rear view mirror adjustments, as well as
fastening of seat belts, must be done before
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
under the seat belt in a collision. If you slide
under it, the belt would apply force at the
abdomen or neck. That could cause serious
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 belts are properly positioned
on the body.
Your seat must be adjusted so that you can
correctly fasten your seat belt (
page 50).
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 position should be as far to the rear
as possible, consistent with ability to
properly operate controls.

Adjust 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
being 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 the SmartKey
with KEYLESS-GO* removed from the
starter switch or the SmartKey with
KEYLESS-GO* 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.

44 Getting started
Adjusting
Seat adjustment
The seat adjustment switch is located on
the entry side of each front seat base.
1 Head restraint height (vehicles with
memory function)*
2Seat cushion tilt
3Seat height
4Seat backrest tilt
5 Seat fore and aft adjustment
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
appropriate infant or toddler restraint, or
booster seat recommended for the size and
weight of the child. For additional informa-
tion, see “Children in the vehicle”
(
page 87).
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.
!When moving the seats, make sure there are
no items in the footwell or behind the seats;
otherwise you could damage the seats.
!When the second-row seats are folded
forward, e.g. for cargo compartment expansion
(
page 292), the front seats may not be moved
to the rearmost position. Otherwise you could
damage the front and second-row seats.
!When adjusting the seat backrest tilt and
head restraint height, make sure the sun visor is
folded up (
page 205). If the head restraint is in
the uppermost position, it could hit and damage
the sun visor.
iVehicles without memory function*:
The seats can be adjusted within 5 minutes after
either front door has been opened. The counter
resets each time

you open or close a front door

you insert the SmartKey into the starter
switch

you remove the SmartKey from the starter
switch

you switch the ignition on or off
iThe memory function* (page 141) lets
you store the settings for the seat position
together with the settings for the steering wheel
and the exterior rear view mirrors.

45 Getting started
Adjusting
Seat fore and aft adjustment
Press the switch forward or backward
in direction of arrow5.
Seat height
Press the switch up or down in
direction of arrow3.
Seat cushion tilt
Press the switch up or down in
direction of arrow2 until your upper
legs are lightly supported.
Seat backrest tilt
Press the switch forward or backward
in direction of arrow4.Head restraint height
Vehicles with memory function*:
Press switch (page 44) up or down in
direction of arrow1.
Vehicles without memory function:
1Head restraint
2Release button
Warning!G
Do not drive the vehicle without the seat
head restraints. Head restraints are
intended to help reduce injuries during an
accident.
With a third-row seat occupied, make sure
to move the respective head restraint up
from the lowest non-use position and have
the occupant adjust the head restraint
properly.
For your protection, drive only with properly
positioned and engaged head restraints.
Adjust the head restraint in such a way 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 potential for injury to the head
and neck in the event of an accident or
similar situation.
!Do not attempt to remove front seat head
restraints. They can only be removed by qualified
technicians. We recommend that you have this
work carried out by an authorized
Mercedes-Benz Light Truck Center.


46 Getting started
Adjusting
Raising:
Manually adjust the height of head
restraint 1 by pulling it upward.
If head restraint 1 is fully retracted,
push release button 2 in direction of
arrow and pull head restraint 1
upward.
Lowering:
To lower head restraint 1, press
release button 2 in direction of arrow
and push down on head restraint 1.Head restraint fore and aft adjustment
Manually adjust the angle of the head
restraint.
While seated, reach behind you with
both hands and find lower edge of the
head restraint.
Adjust the head restraint to the desired
position by pushing or pulling on the
lower edge of the head restraint
cushion.
For more information, see “Seats”
(
page 128).
Steering wheel
Steering wheel adjustment, manual
Warning!G
Only adjust the steering wheel with the
vehicle at a standstill and make sure the
steering wheel is securely locked in place
before driving off.
Driving without the steering wheel adjust-
ment locked may cause an unexpected
steering wheel movement which could
cause the driver to lose control of the
vehicle. Make sure the steering wheel is
securely locked by trying to move it up and
down, and in and out before driving off.


47 Getting started
Adjusting
Make sure that

you can reach the steering wheel with
your arms slightly bent at the elbows

you can move your legs freely

all displays (including malfunction and
indicator lamps) on the instrument
cluster are clearly visible
The steering wheel adjustment release
handle is located on the lower left of the
steering column.
1Release handle
To unlock the steering wheel, pull
release handle 1 out to its stop limit.
Move steering wheel to the desired
position.
Push release handle 1 back to its
original position to relock the steering
wheel.
The steering wheel is locked into posi-
tion again.
Make sure the steering wheel is
securely locked by trying to move it up
and down as well as in and out before
driving off.Steering wheel adjustment, electrical*
Warning!G
Do not adjust the steering wheel while
driving. Adjusting the steering wheel while
driving could cause the driver to lose control
of the vehicle.
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* removed from the starter
switch or the SmartKey with KEYLESS-GO*
removed from the vehicle, the steering
wheel adjustment feature 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.

48 Getting started
Adjusting
Make sure that

you can reach the steering wheel with
your arms slightly bent at the elbows

you can move your legs freely

all displays (including malfunction and
indicator lamps) on the instrument
cluster are clearly visible
The steering wheel adjustment stalk is
located on the lower left of the steering
column.1Adjusting steering wheel, in or out
2Adjusting steering wheel, up or down
Adjusting steering wheel in or out
Move stalk forward or back in direction
of arrow1.
Adjusting steering wheel up or down
Move stalk up or down in direction of
arrow2.
Mirrors
Adjust the interior and exterior rear view
mirrors before driving so that you have
a good view of the road and traffic
conditions.
Interior rear view mirror
Manually adjust the interior rear view
mirror.
For more information, see “Rear view
mirrors” (
page 203).
Exterior rear view mirrors
iThe memory function* (page 141) lets
you store the settings for the steering wheel
together with the settings for seat positions and
the exterior rear view mirrors.
Warning!G
Exercise care when using the
passenger-side exterior rear view mirror.
The mirror surface is convex (outwardly
curved surface for a wider field of view).
Objects in mirror are closer than they ap-
pear. Check your interior rear view mirror or
glance over your shoulder before changing
lanes.

49 Getting started
Adjusting
The buttons are located on the driver’s
door control panel.
1Driver’s side exterior rear view mirror
button
2Adjustment button
3Passenger-side exterior rear view
mirror button
Switch on the ignition (page 39).
Press button1 for the driver’s side
exterior rear view mirror or
button3for the passenger-side
exterior rear view mirror.
The indicator lamp on the respective
button comes on for approximately
15 seconds.
Push adjustment button2up, down,
left, or right according to the desired
setting.
For more information, see “Rear view
mirrors” (
page 203).
iIf you do not make adjustments to the
selected exterior rear view mirror within
15 seconds, the indicator lamp goes out. You will
then have to select the desired exterior rear view
mirror again before any adjustments can be
made. Adjustments can only be made with the
indicator lamp for the respective exterior rear
view mirror button illuminated.
!If an exterior rear view mirror was forcibly
pushed forward (hit from the rear) or forcibly
pushed rearward (hit from the front), reposition
it by applying firm pressure until it snaps into
place. The mirror housing is then properly
positioned and you can adjust the mirror in the
usual manner.
!Vehicles with power folding exterior rear
view mirrors*:
If an exterior rear view mirror housing is forcibly
pushed forward (hit from the rear) or forcibly
pushed rearward (hit from the front) press fold
button1 (
page 205) to fold mirrors in, then
press fold button1 (
page 205) again to fold
mirrors out. Do not force mirrors by hand as this
may damage the adjustment mechanism.
The mirror housing is then properly positioned
and you can adjust the mirror in the usual man-
ner.
Please make sure both rear view mirrors are
folded out before driving off.
iThe memory function* (page 141) lets
you store the settings for the exterior rear view
mirrors together with the setting for the steering
wheel and the seat positions.
At low ambient temperatures, the exterior rear
view mirrors will be heated automatically.