MERCEDES-BENZ R320 2008 W251 Owner's Manual

140 Controls in detail
Seats
Switching on
Press switch1.
Three red indicator lamps2 in the
switch come on.
Continue pressing switch1 until
desired seat heating level is reached.
Switching off
Press switch1 repeatedly until all
indicator lamps2 go out.
Seat ventilation* (Canada only)
Seat ventilation is available on the
R 550 4MATIC only.
The switches for the seat ventilation are
located in the center console.
1Seat ventilation switch
2Indicator lampsThe blue indicator lamps in the switch
come on to show which ventilation level
you have selected.
Switch on the ignition (page 39).
Switching on
Press switch1 repeatedly until the
desired ventilation level is set.
Switching off
Press switch1 repeatedly until all
indicator lamps2 go out.
iIf one or more of the indicator lamps2 on
seat heating switch 1 (
page 139) are flash-
ing, there is insufficient voltage due to too many
electrical consumers being switched on. The
seat heating switches off automatically.
The seat heating will switch back on again
automatically as soon as sufficient voltage is
available.
Level
3Three indicator lamps on
(highest level)
2Two indicator lamps on
1One indicator lamp on
(lowest level)
offNo indicator lamp on
iThe seat ventilation for the driver’s seat is
automatically set to the highest level if activated
via summer opening feature (
page 244).

141 Controls in detail
Memory function*
Memory function*
Prior to operating the vehicle, the driver
should check and adjust the seat height,
seat position fore and aft, and seat back-
rest angle if necessary, to ensure adequate
control, reach and comfort. The head
restraint should also be adjusted for
proper height. See also the section on air
bags (
page 72) for proper seat position-
ing.
In addition, adjust the steering wheel to
ensure adequate control, reach, operation
and comfort. Both the interior and exterior
rear view mirrors should be adjusted for
adequate rear vision.
Fasten seat belts. Infants and small chil-
dren should be seated in a properly
secured restraint system that complies
with U.S. Federal Motor Vehicle Safety
Standards 213 and 225 and Canadian
Motor Vehicle Safety Standards 213
and 210.2.With the memory function you can store up
to three different configuration.
Each stored position on the driver’s side
includes the following settings:

Seat position

Multicontour seat*: previously saved
setting

Steering wheel position

Exterior rear view mirrors’ position
Each stored position on the passenger side
includes the following settings:

Seat position

Multicontour seat*: previously saved
settingThe memory button and stored position
buttons are located on the entry side of
each front seat base.
MMemory button
1, 2, 3Stored position buttons
Warning!G
Do not activate the memory function while
driving. Activating the memory function
while driving could cause the driver to lose
control of the vehicle.

142 Controls in detail
Memory function*
Storing positions into memory
Adjust the seat (page 44).
On the driver’s side, additionally adjust
the steering wheel (
page 46) and
exterior rear view mirrors (
page 48)
to the desired positions.
Press memory buttonM.
Release memory button M and press
stored position button1, 2 or 3 within
3 seconds.
When the settings are stored to the
selected position, an acknowledge-
ment signal sounds.
Recalling positions from memory
Press and hold stored position
button1,2 or3 until the seat, steering
wheel and exterior rear view mirrors
have fully moved to the stored posi-
tions.
!Do not operate the power seats using mem-
ory button M if the seat backrest is in an exces-
sively reclined position. Doing so could cause
damage to front or rear seats.
Move seat backrest to an upright position first.
iReleasing the stored position button stops
movement to the stored positions immediately.

143 Controls in detail
Lighting
Lighting
For information on how to switch on the
headlamps and use the turn signals, see
“Switching on headlamps” (
page 58)
and “Turn signals” (
page 59).
Exterior lamp switch
iIf you drive in countries where vehicles drive
on the other side of the road than the country in
which the vehicle is registered, you must have
the headlamps modified for symmetrical low
beams. Relevant information can be obtained at
any authorized Mercedes-Benz Light Truck
Center.
iVehicles with active Bi-Xenon* headlamps:
The active Bi-Xenon* headlamps monitor the
vehicle’s steering angle and speed, then auto-
matically shift their beams to either side to
better follow the curvature of the road ahead, in-
creasing usable illumination over conventional
headlamps.1‚Standing lamps, left
(turn left two stops)
2ˆStanding lamps, right
(turn left one stop)
3MOff
Daytime running lamp mode
(
page 145)
4UAutomatic headlamp mode
Daytime running lamp mode
(
page 145)
5CParking lamps (also side marker
lamps, tail lamps, license plate
lamps, instrument panel lamps)
6BLow beam headlamps or high
beam headlamps
7‡Front fog lamps
8†Rear fog lamp
iThe exterior lamps switch off automatically
when you remove the SmartKey from the starter
switch or open the driver’s door with the ignition
switched off.
When the parking lamps or the rear fog lamp are
switched on and you remove the SmartKey from
the starter switch or open the driver’s door, an
acoustic signal sounds.
In addition the message
Switch Off Lights
appears in the multifunction display.
Switch off the parking lamps or the rear fog lamp
manually.
!Failure to switch off the parking lamps when
leaving the vehicle may result in a discharged
battery.

144 Controls in detail
Lighting
Low beam headlamps
Turn the exterior lamp switch to
positionB.
With the SmartKey in starter switch
position1or the KEYLESS-GO*
start/stop button pressed once, the
following lamps will switch on:

Tail and parking lamps

License plate lamps

Side marker lamps
With the SmartKey in starter switch
position1or the KEYLESS-GO*
start/stop button pressed once,
the following lamps will switch on addi-
tionally:

Low beam headlamps

High beam headlamps (when the
combination switch is pushed
forward)Automatic headlamp mode
The following lamps switch on and off
automatically depending on the brightness
of the ambient light:

Low beam headlamps

Tail and parking lamps

License plate lamps

Side marker lamps
Warning!G
If the exterior lamp switch is set toU,
the headlamps will not be automatically
switched on under foggy conditions.
To minimize risk to you and to others,
activate headlamps by turning exterior lamp
switch toB when driving or when traffic
and/or ambient lighting conditions require
you to do so.
In low ambient lighting conditions, only
switch from positionU toB with the
vehicle at a standstill in a safe location.
Switching fromUtoB will briefly
switch off the headlamps. Doing so while
driving in low ambient lighting conditions
may result in an accident.
The automatic headlamp feature is only an
aid to the driver. The driver is responsible for
the operation of the vehicle’s lights at all
times.

145 Controls in detail
Lighting
Turn the exterior lamp switch to
positionU.
With the SmartKey in starter switch
position1 or the KEYLESS-GO*
start/stop button pressed once, only
the parking lamps and the side marker
lamps will switch on and off depending
on the brightness of the ambient light.
When the engine is running, the low
beam headlamps, the tail and parking
lamps, the license plate lamps, and the
side marker lamps will switch on and
off depending on the brightness of the
ambient light.Daytime running lamp mode
In Canada the daytime running lamp mode
is mandatory and therefore in a constant
mode.
In the USA the daytime running lamp mode
is deactivated by default. Activate the day-
time running lamp mode using the control
system, see “Setting daytime running lamp
mode (USA only)” (
page 177).
Turn the exterior lamp switch to
positionM orU.
When the engine is running, the low
beam headlamps are switched on.
In low ambient light conditions, the
following lamps will switch on addition-
ally:

Tail and parking lamps

License plate lamps

Side marker lampsCanada only:
When the engine is running and you shift
from a driving position to positionN orP
with the vehicle at a standstill, the low
beam headlamps will switch off with a
three-minute delay.
When the engine is running and you

turn the exterior lamp switch to
positionC, the low beam head-
lamps, the tail and parking lamps, the
side marker lamps and the license
plate lamps switch on

turn the exterior lamp switch to
positionB, the manual headlamp
mode has priority over the daytime
running lamp mode
iCanada only:
High beam headlamps are only available with the
exterior lamp switch in position B.
iWith the daytime running lamp mode activat-
ed and the engine running, you cannot switch off
the low beam headlamps manually.
iWith the exterior lamp switch in
positionM orU, you cannot switch on the
high beam headlamps.
The high beam flasher is available at all times.
For nighttime driving, turn the exterior lamp
switch in positionB to permit activation of
the high beam headlamps.

146 Controls in detail
Lighting
USA only
When the engine is running, and you turn
the exterior lamp switch to positionC
orB, the manual headlamp mode has
priority over the daytime running lamp
mode.
The corresponding exterior lamps switch
on (
page 143).Locator lighting and night security
illumination
The locator lighting and the night security
illumination are described in the “Control
system” section, see “Setting locator light-
ing” (
page 178) and “Setting night secu-
rity illumination” (
page 179).Fog lamps
iWith the daytime running lamp mode
activated and the exterior lamp switch in
positionM, you cannot switch on the high
beam headlamps.
The high beam flasher is available at all times.
For nighttime driving, turn the exterior lamp
switch in positionB orU to permit
activation of the high beam headlamps.
Warning!G
In low ambient lighting or foggy conditions,
only switch from positionU toB with
the vehicle at a standstill in a safe location.
Switching fromU toB will briefly
switch off the headlamps. Doing so while
driving in low ambient lighting conditions
may result in an accident.
iFog lamps will operate with the parking
lamps and/or the low beam headlamps on. Fog
lamps should only be used in conjunction with
low beam headlamps. Consult your State or
Province Motor Vehicle Regulations regarding
permissible lamp operation.
iFog lamps cannot be switched on with the
exterior lamp switch in positionU. To switch
on the fog lamps, turn the exterior lamp switch to
positionB first.

147 Controls in detail
Lighting
Front fog lamps
Turn the exterior lamp switch to
positionC orB (
page 143).
Pull out the exterior lamp switch to first
stop.
The front fog lamps switch on.
The green indicator lamp‡ in the
exterior lamp switch comes on.
Push in the exterior lamp switch.
The front fog lamps switch off.
The green indicator lamp‡ in the
exterior lamp switch goes out.Rear fog lamp (driver’s side only)
Turn the exterior lamp switch to
positionB (
page 143).
Pull out the exterior lamp switch to
second stop.
The rear fog lamp switches on.
The yellow indicator lamp† in the
exterior lamp switch comes on.
Push in the exterior lamp switch to first
stop.
The rear fog lamp switches off.
The yellow indicator lamp† in the
exterior lamp switch goes out.
The front fog lamps remain lit.
Combination switch
1High beam
2High beam flasher
High beam
Turn the exterior lamp switch to
positionB (
page 143).
iThe front fog lamps will also switch on.


148 Controls in detail
Lighting
Push the combination switch in
direction of arrow1 to switch on the
high beam.
The high beam headlamp indicator
lampAin the instrument cluster
comes on (
page 29).
Pull the combination switch in direction
of arrow2 to its original position to
switch off the high beam.
The high beam headlamp indicator
lampAin the instrument cluster
goes out.
High beam flasher
Pull the combination switch briefly in
direction of arrow2.
Corner-illuminating front fog lamps*
The corner-illuminating front fog lamps
improve illumination of the area in the
direction into which you are turning.
The corner-illuminating front fog lamps will
operate with the engine running and with

the exterior lamp switch in
positionB (
page 143)
or

the exterior lamp switch in
positionU (
page 143)
or

the daytime running lamp mode
activated (
page 145)Driving forward
Switching on corner-illuminating front
fog lamps
Switch on the left or right turn signal
(
page 59), depending on whether
you are turning left or right.
The respective front fog lamp comes on
and illuminates the area in the
direction into which you are turning.
or
Turn steering wheel in desired direc-
tion.
The front fog lamp on the side of your
steering direction comes on.
iThe corner-illuminating front fog lamps will
only come on in low ambient lighting conditions.
iIf you are driving faster than
25 mph (40 km/h) or have the front fog lamps
switched on, the corner-illuminating function is
not available.
iIf you have switched on the turn signal for
one side but turn the steering wheel in the
opposite direction, the corner-illuminating front
fog lamp comes on for the side indicated by the
turn signal.
The corner-illuminating front fog lamp remains lit
for a maximum of three minutes. Afterwards, it
goes out even if the turn signal is still switched
on.


149 Controls in detail
Lighting
Switching off corner-illuminating front
fog lamps
The combination switch for the turn signal
resets automatically after major steering
wheel movements. This will switch off the
corner-illuminating front fog lamps if they
were activated by switching on the left or
right turn signal.
If the turn signal should stay on after
making the turn, the turn signal and
corner-illuminating front fog lamps can be
switched off by returning the combination
switch to its original position.Driving in reverse
Switching on corner-illuminating front
fog lamps
Shift the automatic transmission to
reverse gearR (
page 192).
The front fog lamp opposite to your
steering direction comes on.
Switching off corner-illuminating front
fog lamps
Shift the automatic transmission
to a gear other than reverse
gearR(
page 190).
The respective front fog lamp goes out.
iThe corner-illuminating front fog lamps tem-
porarily come on both sides of the vehicle if you
turn the steering wheel in one direction and then
again in the other direction shortly thereafter.
iThe corner-illuminating front fog lamps will
come on automatically depending on the steer-
ing angle, even if you did not switch on either
turn signal. If the corner-illuminating front fog
lamps came on automatically, they will also go
out automatically depending on the steering
angle.
iThere may be a brief delay before the
corner-illuminating front fog lamps switch off.