2007 MERCEDES-BENZ GL450 ac controls

194 Controls in detail
Automatic transmission
Shifting from P to R
With the vehicle at a standstill, depress
the brake pedal and keep it pressed.
Move gear selector lever up past the re-
sistance point to select reverse gearR.
Release the parking brake (page 60).
Release the brake pedal.
Carefully depress the accelerator pedal
to drive off when it is safe to do so.Shifting from P to D
With the vehicle at a standstill, depress
the brake pedal and keep it pressed.
Move gear selector lever down past the
resistance point to select drive
positionD.
Release the parking brake (page 60).
Release the brake pedal.
Carefully depress the accelerator pedal
to drive off when it is safe to do so.Shifting from D, R, or N to P
If you want to select park positionP with
the transmission being in drive positionD,
reverse positionR or neutral positionN:
With the vehicle at a standstill, depress
the brake pedal and keep it pressed.
Step firmly on parking brake pedal
(
page 68).
Press button on gear selector lever in
direction of arrow (
page 192) to
select park positionP.
Release the brake pedal.
iThe gear selector lever returns to its original
position.
iThe gear selector lever returns to its original
position.
!Shift the automatic transmission directly
from drive positionD to reverse gearR, from
reverse gearR to drive positionD or directly to
park positionP only when the vehicle is stopped.
Otherwise the automatic transmission could be
damaged.
When trying to free a vehicle stuck in mud or
snow, see “Rocking the vehicle” (
page 199).

195 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 68).
Move gear selector lever up to resis-
tance point when in drive positionD or
down to resistance point when in
reverse gearR to select neutral
positionN.
Release the brake pedal.
Shifting procedure
The automatic transmission selects indi-
vidual gears automatically, depending on:

drive positionD (page 195) with gear
ranges (
page 200)

the position of the accelerator pedal
(
page 198)

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
Transmission positions
The current transmission position appears
in the multifunction display.
1Current transmission position
iWhen the vehicle needs to be moved with
the engine switched off and the transmission set
to neutral positionN (
page 195), 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.
!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.
Do not limit the gear range.

196 Controls in detail
Automatic transmission
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,
the transmission will shift to park positionP
automatically. Keep in mind that turning off the
engine with the SmartKey alone will not automat-
ically shift the transmission to park positionP.
!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 will not automatically shift the
transmission to park positionP.
iEven though this is possible, make it a prac-
tice to always shift into park positionP before
turning off the engine and remove the SmartKey
from the starter switch, or when using
KEYLESS-GO*, before turning off the engine with
the start/stop button and opening 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 transmis-
sion, 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.
êDrive
The transmission shifts
automatically. All forward gears
are available.

197 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.Vehicles with SmartKey:
With the vehicle at a standstill and the
ignition switched on shift the automatic
transmission to neutral positionN.
If engaged, release the parking brake
(
page 60).
Switch off the ignition and leave the
SmartKey in the starter switch.
Vehicles with KEYLESS-GO*:
With the vehicle at a standstill, depress
the brake pedal and keep it pressed.
With the ignition switched on shift the
automatic transmission to park
positionP.
Release the brake pedal.
Remove the KEYLESS-GO* start/stop
button from the starter switch
(
page 43).
Insert the SmartKey with
KEYLESS-GO* into the starter switch.
Switch on the ignition.
Depress the brake pedal.
Shift the automatic transmission to
neutral positionN.
Release the brake pedal.
If engaged, release the parking brake
(
page 60).
Switch off the ignition and leave the
SmartKey with KEYLESS-GO* in the
starter switch.
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.
!Coasting the vehicle, or driving for any other
reason in neutral positionN can result in
transmission damage that is not covered by the
Mercedes-Benz Limited Warranty.

198 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 upshiftingKickdown
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.
Warning!G
Getting out of your vehicle without shifting
into park positionP is dangerous. Also, park
positionP alone is not intended to or capa-
ble of preventing your vehicle from moving,
possibly hitting people or objects.
Always set the parking brake in addition to
shifting to positionP (
page 68).
When parked on an incline, turn the front
wheels towards the road curb.
Do not park this vehicle in areas where com-
bustible materials such as grass, hay or
leaves can come into contact with the hot
exhaust system, as these materials could be
ignited and cause a vehicle fire.
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.

199 Controls in detail
Automatic transmission
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.
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 vehicle
Hill start assist systemOn 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 position
P.

200 Controls in detail
Automatic transmission
Towing a trailer
If you tow a trailer, note the following
points:

Manually shift to a lower gear range
(
page 200) if the transmission hunts
between gears on inclines.
A lower gear range and reduction of
speed reduces the chance to overload
or overheat the engine.
For more information on trailer towing, see
the “Operation” section (
page 366).
Gear ranges
With the automatic transmission in drive
positionD, you can select a gear range for
the automatic transmission to operate
within.
You can limit the gear range by pressing
the left gearshift button on the steering
wheel gearshift control, and reverse the
gear range limit by pressing the right gear-
shift button on the steering wheel gearshift
control (
page 201).The selected gear range appears in the
multifunction display.
1Current gear range
Effect
ïThe transmission shifts through
sixth gear only.
îThe transmission shifts through
fifth gear only.
éThe transmission shifts through
fourth gear only.
èThe transmission shifts through
third gear only.
With this selection you can use
the braking effect of the engine.
Effect
çThe transmission shifts through
second gear only.
Allows the use of engine’s
braking power when driving:

on steep downgrades

in mountainous regions

under extreme operating
conditions
æThe transmission operates in
first gear only.
For maximum use of engine’s
braking effect on very steep or
lengthy downgrades.

201 Controls in detail
Automatic transmission
Steering wheel gearshift control
With drive positionD selected, you can
limit or extend the gear range.
1Left button: limiting gear range or
downshift
2Right button: extending gear range or
upshiftDownshifting
Briefly press left shift button1.
The transmission will shift to the next
lower gear as permitted by the shift
program. This action simultaneously
limits the gear range of the automatic
transmission (
page 200).
!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.
iYou cannot shift with the steering wheel
gearshift buttons when the transmission is in
positionP,N orR.
Warning!G
On slippery road surfaces, never downshift
in order to obtain braking action. This could
result in drive wheel slip and reduced
vehicle control. Your vehicle’s ABS will not
prevent this type of loss of control.
iTo avoid overrevving the engine when down-
shifting, the transmission will not shift to a lower
gear if the engine’s max. speed would be ex-
ceeded.