engine MERCEDES-BENZ R320 2008 W251 Workshop Manual

181 Controls in detail
Control system
Zone map South America
Press buttonæ orç to move
the selection marker to the
Vehicle
submenu.
Press buttonj ork repeatedly
until the message
Compass Setting
Zone
appears in the multifunction
display.
The selection marker is on the current
setting.
Press buttonæ orç to set the
respective compass zone.
For information on how to call up the
compass, see “Compass” (
page 334).Compass calibration
This function is not available if your vehicle
is equipped with the COMAND system and
navigation module*.
In order to calibrate the compass properly,
mind the following:

Calibrate the compass in open terrain.
Nearby buildings, bridges, power lines
and large antenna masts, for example,
could impair compass calibration.

Switch off electrical consumers (e.g.
climate control, windshield wipers, or
rear window defroster).

Close all doors and the tailgate.
Start the engine (page 53).
Press buttonæ orç to move
the selection marker to the
Vehicle
submenu.
iMake sure you are in an area where you can
drive a full circle with your vehicle without dis-
turbing traffic in order to calibrate your compass.


186 Controls in detail
Control system
Fuel consumption statistics since start
Press buttonÿ orè repeatedly
until the message
From Start appears
in the multifunction display.
1Distance driven since start
2Time elapsed since start
3Average speed since start
4Average fuel consumption since startFuel consumption statistics since last
resetPress buttonÿ orè repeatedly
until the message
From Start appears
in the multifunction display.
Press buttonj ork repeatedly
until the message
From Reset appears
in the multifunction display.
1Distance driven since last reset
2Time elapsed since last reset
3Average speed since last reset
4Average fuel consumption since last
resetResetting fuel consumption statistics
Press buttonÿ orè repeatedly
until the message
From Start appears
in the multifunction display.
Press buttonj ork repeatedly
until the fuel consumption statistics
which you want to reset appear in the
multifunction display.
Press and hold the reset button in the
instrument cluster (
page 154) until
the respective values are reset to
0.
iAll statistics stored since the last engine
start will be reset approximately 4 hours after
the SmartKey in the starter switch is turned to
position0 or removed from the starter switch.
Resetting will not occur if you turn the SmartKey
back to position1 or2 within this time period.
iThe fuel consumption statistics reset auto-
matically to
0 when either of the following values
is exceeded:

distance covered: 100 000 miles

time elapsed: 10 000 hours

187 Controls in detail
Control system
Distance to empty
Press buttonÿ orè repeatedly
until the message
From Start appears
in the multifunction display.
Press buttonj ork repeatedly
until the message
Range: appears in
the multifunction display.
The calculated remaining driving range
based on the current fuel tank level
appears in the multifunction display.
TEL menu*
You can use the functions in the
TEL menu
to operate your telephone, provided it is
connected to a hands-free system and
switched on.
Switch on the telephone and COMAND
system.
Press buttonÿ orè on the
multifunction steering wheel repeat-
edly until the message
TEL appears in
the multifunction display.
iIf only very little fuel is left in the tank, a
vehicle at the fuel pump is shown instead of the
range.
Warning!G
A driver’s attention to the road must always
be his/her primary focus when driving. For
your safety and the safety of others, we
recommend that you pull over to a safe
location and stop before placing or taking a
telephone call. If you choose to use the tele-
phone while driving, please use the
hands-free device and only use the tele-
phone when weather, road and traffic
conditions permit.
Some jurisdictions prohibit the driver from
using a cellular telephone while driving a
vehicle.
Bear in mind that at a speed of just 30 mph
(approximately 50 km/h), your vehicle is
covering a distance of 44 feet
(approximately 14 m) every second.
Never operate radio transmitters equipped
with a built-in or attached antenna (i.e. with-
out being connected to an external antenna)
from inside the vehicle while the engine is
running. Doing so could lead to a malfunc-
tion of the vehicle’s electronic system,
possibly resulting in an accident and/or
personal injury.

190 Controls in detail
Automatic transmission
For information on driving with an
automatic transmission see “Automatic
transmission” (
page 53).
Your vehicle’s transmission adapts its gear
shifting process to your individual driving
style by continually adjusting the shift
points up or down. These shift point adjust-
ments are performed based on current
operating and driving conditions.
If the operating conditions change, the
automatic transmission reacts by
adjusting its shift program.
Gear selector lever
The gear selector lever is located on the
right of the steering column.
Gearshift pattern for automatic
transmission
PPark position
RReverse gear
NNeutral
DDrive position
iDuring the brief warm-up, transmission
upshifting is delayed. This allows the catalytic
converter (gasoline engine) or the oxidation
catalyst (diesel engine) to heat up more quickly
to operating temperature.
Warning!G
Make sure that absolutely no objects are
obstructing the pedals’ range of movement.
Keep the driver’s footwell clear of all obsta-
cles. If there are any floormats or carpets in
the footwell, make sure that the pedals still
have sufficient clearance.
During sudden driving or braking maneuvers
the objects could get caught between the
pedals. You could then no longer brake or
accelerate. This could lead to accidents and
injury.

191 Controls in detail
Automatic transmission
Shifting from P to N
Moving the gear selector lever up or down
shifts the automatic transmission out of
park positionP:
With the vehicle at a standstill, depress
the brake pedal and keep it pressed.
Move gear selector lever up or down to
resistance point to select neutral
positionN.Shifting from N to R or from N to D
With the vehicle at a standstill, depress
the brake pedal and keep it pressed.
Move gear selector lever up past the
resistance point to select reverse
gearR.
or
Move gear selector down past the
resistance point to select drive
positionD.
Release the parking brake (page 56).
Release the brake pedal.
Carefully depress the accelerator pedal
to drive off when it is safe to do so.
iThe current transmission positionP, R, N
orD appears in the multifunction display
(
page 194).
Warning!G
It is dangerous to shift the automatic trans-
mission out of park positionP or neutral
positionN if the engine speed is higher than
idle speed. If your foot is not firmly on the
brake pedal, the vehicle could accelerate
quickly forward or reverse. You could lose
control of the vehicle and hit someone or
something. Only shift into gear when the
engine is idling normally a n d w h e n y o u r r i g h t
foot is firmly on the brake pedal.
iThe gear selector lever returns to its original
position.
iThe gear selector lever returns to its original
position.

193 Controls in detail
Automatic transmission
Shifting from D or R to N
If you want to select neutral positionN
with the transmission being in drive
positionD or reverse gearR:
With the vehicle at a standstill, depress
the brake pedal and keep it pressed.
Step firmly on parking brake pedal
(
page 65).
Move gear selector lever up to resis-
tance point when in drive position D or
down to resistance point when in
reverse gear R to select neutral
positionN.
Release the brake pedal.
Shifting procedure
The automatic transmission selects indi-
vidual gears automatically, depending on:

drive positionD (page 194) with
gear ranges (
page 199)

the selected program mode (C/S)
(
page 200)

the position of the accelerator pedal
(
page 197)

the vehicle speedWith drive positionD selected, you can use
the steering wheel gearshift control
buttons (page 201) to influence trans-
mission shifting by:

limiting the gear range

changing gears manually
iWhen the vehicle needs to be moved with
the engine switched off and the transmission set
to neutral positionN (
page 194), do not
depress the parking brake pedal.
!Allow engine to warm up under low load use.
Do not place full load on the engine until the
operating temperature has been reached.
Shift into reverse gearR or park positionP only
when the vehicle is stopped.
Avoid spinning of a drive wheel for an extended
period when driving off on slippery road
surfaces. This may cause serious damage to the
drivetrain which is not covered by the
Mercedes-Benz Limited Warranty.

194 Controls in detail
Automatic transmission
Transmission positions
The current transmission position appears
in the multifunction display.
1Current transmission position
!If the current transmission position does not
appear in the multifunction display due to a
malfunction, for example, make sure that the
automatic transmission is in the desired position
by carefully driving off with the transmission in
drive positionD and program modeS
(
page 200) selected. Do not limit the gear
range.
Effect
ìPark position
Shift into park positionP only
when vehicle is stopped. The
park position is not intended to
serve as a brake when the vehi-
cle is parked. Rather, the driver
should always set the parking
brake in addition to shifting into
park positionP to secure the
vehicle.
If the vehicle’s electrical system
is malfunctioning, the automatic
transmission could remain
locked in park positionP.
Have the vehicle checked as
soon as possible by an autho-
rized Mercedes-Benz Light
Truck Center.
!SmartKey:
If you turn off the engine using the SmartKey and

remove the SmartKey from the starter
switch
or

open a front door
the transmission will shift to park positionP
automatically.
Keep in mind that turning off the engine with the
SmartKey alone only will automatically shift the
transmission to neutral positionN.
!KEYLESS-GO*:
If you turn off the engine using the KEYLESS-GO
start/stop button and open a front door, the
transmission will shift to park positionP
automatically.
Keep in mind that turning off the engine using
the KEYLESS-GO start/stop button alone only
will automatically shift the transmission to
neutral positionN.

195 Controls in detail
Automatic transmission
If you want the gear position to remain in
neutral positionN, e.g. when taking the
vehicle through an automatic conveyor
type car wash, observe the following
instructions.
iMake it a practice to always shift into park
positionP before turning off the engine and

remove the SmartKey from the starter
switch
or

open a front door
or when using KEYLESS-GO*, before turning off
the engine with the start/stop button and open-
ing a front door.
Effect
íReverse gear
Shift into reverse gearR only
when the vehicle is stopped.
ëNeutral
No power is transmitted from the
engine to the drive axle. When
the brakes are released, the
vehicle can be moved freely
(pushed or towed).
To avoid damage to the trans-
mission, never shift into neutral
positionN while driving.
If the ESP
® is deactivated or
malfunctioning:
Shift into neutral positionN only
if the vehicle is in danger of
skidding, e.g. on icy roads.
!If you turn off the engine using the
SmartKey or the KEYLESS-GO* start/stop
button, the transmission will shift to neutral
positionN automatically.
Warning!G
When leaving the SmartKey or SmartKey
with KEYLESS-GO* in the starter switch, do
not leave children unattended in the vehicle.
It is possible for children to switch on the
ignition which could result in unsupervised
use of vehicle equipment.
A child’s unsupervised access to a vehicle
could result in an accident and/or serious
personal injury.

197 Controls in detail
Automatic transmission
Driving tips
Accelerator position
Your driving style influences the
transmission’s shifting behavior:
Less throttle Earlier upshifting
More throttle Later upshifting
Kickdown
Use kickdown when you want maximum
acceleration.
Press the accelerator past the point of
resistance.
Depending on the engine speed the
transmission shifts into a lower gear.
Ease on the accelerator when you have
reached the desired speed.
The transmission shifts up again.Stopping
When you stop briefly, e.g. at traffic lights:
Leave the transmission in gear.
Hold the vehicle with the brake.
When you stop for a longer period of time
with the engine idling and/or on a hill:
Set the parking brake.
Shift into park positionP.
Maneuvering
When you maneuver in tight areas,
e.g. when pulling into a parking space:
Control the vehicle speed by gradually
releasing the brakes.
Accelerate gently.
Never abruptly step on the accelerator.
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. Children could shift the
automatic transmission out of park
positionP, which could result in an accident
and/or serious personal injury.

198 Controls in detail
Automatic transmission
Rocking the vehicle
Rocking the vehicle by shifting between
drive positionD and reverse gearR can
help free a vehicle stuck in mud or snow.
The engine control system of this vehicle
electronically limits shifting between
drive positionD and reverse gearR to
very low speeds, i.e. approximately
5 mph (9 km/h). To shift between drive
positionD and reverse gearR, move the
gear selector lever past the resistance
point up or down.
Working on the vehicleHill start assist system
On uphill grades with a gradient angle of
more than 5°, the hill start assist system
maintains the pressure in the brake sys-
tem for approximately 1 second after you
have released the brake pedal. Therefore,
you can start off smoothly without the
vehicle moving immediately after releasing
the brake pedal.The hill start assist system is inactive

when starting off on a level road or
downhill grades

with the transmission in neutral
positionN

with the parking brake set

if the ESP® has switched off due to a
malfunction
Warning!G
When working on the vehicle, set the
parking brake and shift to park positionP.
Otherwise the vehicle could roll away.
Warning!G
The hill start assist system is not designed
to function as a parking brake and does not
prevent the vehicle from moving when
parked on an incline.
Always set the parking brake in addition to
shifting to park positionP.