2007 MERCEDES-BENZ GL320CDI engine

204 Controls in detail
Transfer case
Switching LOW RANGE mode
The switch is located on the upper part of
the center console.
1LOW RANGE switch
2Indicator lamp
3LOW RANGE displaySwitching LOW RANGE mode on
(switching from HIGH RANGE to LOW
RANGE)
Press LOW RANGE switch1.
Indicator lamp2 flashes.
If the system senses that all conditions
are met, it will switch to LOW RANGE
mode. A chime sounds and the LOW
RANGE display3 appears in the multi-
function display.
The indicator lamp2 on the
LOW RANGE switch comes on continu-
ously, indicating that the LOW RANGE
mode has been activated.
Warning!G
Always wait until the procedure of shifting
from HIGH RANGE to LOW RANGE – and
from LOW RANGE to HIGH RANGE – has
been entirely completed. During this proce-
dure do not:

switch off the engine

shift the automatic transmission into
another gear
If you do not wait until the shifting proce-
dure has been entirely completed then it
might not be correctly performed. The trans-
fer case might be in neutral, thus interrupt-
ing the transfer of power between the
engine and the drive axle.
The vehicle is then freely movable, even if a
gear has been selected, and could uninten-
tionally be set into motion – particularly on
up – or downhill grades. This could lead to
an accident and cause injury to yourself and
others.
Please observe related messages appearing
in the multifunction display (
page 493).
!The shift procedure can only be performed
when the following conditions are met:

The engine is running (page 41).

The automatic transmission is in positionN
(
page 193).

The vehicle speed does not exceed 25 mph
(40 km/h).
iThere is no reset to HIGH after the ignition
has been switched off.

205 Controls in detail
Transfer case
Switching LOW RANGE mode off
(switching from LOW RANGE to HIGH
RANGE)
Press LOW RANGE switch1
(
page 204).
Indicator lamp2 flashes.
If the system senses that all conditions
are met, it will switch to back to
HIGH RANGE mode. A chime sounds
and the LOW RANGE display3 ap-
pears in the multifunction display.
The indicator lamp2 on the
LOW RANGE switch goes out, indicat-
ing that the LOW RANGE mode has
been deactivated.
For messages in the multifunction display,
see “Practical hints” section (
page 493).
iYou can cancel the procedure by pressing
the LOW RANGE switch again while the indicator
lamp is flashing.
!The shift procedure can only be performed
when the following conditions are met:

The engine is running (page 41).

The automatic transmission is in positionN
(
page 193).

The vehicle speed does not exceed 43 mph
(70 km/h).
iThere is no reset to LOW after the ignition
has been switched off.
iYou can cancel the procedure by pressing
the LOW RANGE switch again while the indicator
lamp is flashing.

206 Controls in detail
Differential locks*
For more information on Off-road driving,
see “Off-road driving” (
page 357).
Vehicles with enhanced off-road package*
are equipped with automatic locks for the
center and rear axle differential to improve
vehicle traction.

The center differential compensates
for differences in wheel rotation be-
tween the front and rear axle.

The rear axle differential compensates
differences between the rear wheels.A few words about differentials and
differential locks*
When a vehicle negotiates a turn, wheels
on the outside of the curve must travel far-
ther and rotate faster than the inside
wheels. The differential, the operation of a
set of gears that allows the powered
wheels in a vehicle to turn at different
speeds, makes this essential function pos-
sible.
The drawback is that the differential also
sends most of the engine’s power to the
wheel with the least load or strain on it. For
example, if one of a vehicle’s powered
wheels sits on a patch of snow and spins
because there is no traction, all of the en-
gine’s power will go to that wheel because
the power will take the path of least resis-
tance. Meanwhile, the opposite wheel, sit-
ting on dry pavement where it could get
enough grip to start the vehicle moving,
sits idle because it receives no power.The Electronic Traction System (ETS) ad-
dresses this problem and provides for
good control and steering ability by auto-
matically slowing the slipping wheel and
thus increasing the power to the other
non-slipping drive wheels to get the vehicle
moving. The ESP
® and ETS in this vehicle
feature such intelligent limited-slip differ-
ential technology, ideally suited for
on-road and light off-road driving. Transfer
case position LOW (
page 203) also en-
hances off-road driving capabilities
(
page 357).
More extreme off-road conditions may call
for another solution, engaging a differen-
tial lock or preventing the differential from
operating altogether. This vehicle comes
with two differential locks: transfer case
(center) and rear. Each can be engaged
simply by operating a rotary switch located
on the center console (
page 207). When
the transfer case (center) differential is
locked, the combined (or average) speed
of the front wheels is identical to the com-
bined rear wheel speed. When the rear
differential is locked, both rear wheels turn
iAt the front axles, the 4-ETS system
(
page 109) compensates for any traction
problems.

208 Controls in detail
Differential locks*
AUTO mode
The AUTO mode is adequate for most driv-
ing situations since the center differential
is locked and released as required.
Start the engine (page 42).
The center differential locks is in AUTO
mode. The indicator lamp on the
adjustment ring1 above
symbolU2 is on.Center and rear axle differential locksThe differential locks should only be
engaged manually if traction is insufficient
in AUTO mode.
The differential locks can be engaged in
the sequence3, 4 (
page 207) up to a
speed of 19 mph (30 km/h).
Engaging differential locks:

for off-road driving

for driving through water

when driving on deep snow and icy or
fouled surfaces
iAt speeds up to 19 mph (30 km/h), it is
possible to manually lock the differential locks
for driving on rough terrain.
Warning!G
Never drive on a paved surface with the
center and rear axle differential locks
manually engaged. Ability to steer the
vehicle is greatly reduced when the differen-
tial locks are manually engaged, increasing
the risk of an accident.
For safety reasons, the locks are automati-
cally released at a vehicle speed above
31 mph (50 km/h). Nevertheless, you
should only manually lock the differential if
absolutely necessary because engaged
locks will restrict the vehicle drive train
while cornering and cause the vehicle to
chatter. This could cause you to lose control
of the vehicle and cause an accident.
!The differential locks must not be engaged
manually when towing the vehicle or spinning the
wheels.

209 Controls in detail
Differential locks*
Start the engine (page 42).
To select the required locking mode,
rotate adjustment ring2 to the
desired position3 or4
(
page 207).
The indicator lamp on the adjustment
ring1 at the respective symbol
comes on.
Example
5Center differential is completely locked
!If the differential locks have been manually
engaged, the tires will scuff on the road surface
when cornering because the differences be-
tween the individual wheel rotation speeds will
not be compensated for.
iThe differential locks are reset to AUTO
mode after the ignition has been switched off for
longer than 10 seconds.

219 Controls in detail
Climate control
The climate control is operational whenev-
er the engine is running. You can operate
the climate control system in either the
automatic or manual mode. The system
cools or heats the interior depending on
the selected interior temperature and the
current outside temperature.Nearly all dust particles, pollutants and
odors are filtered out before outside air en-
ters the passenger compartment through
the air distribution system.
The air conditioning will not engage (no
cooling) if the A/C mode is deactivated
(
page 226).
Warning!G
When operating the climate control, the air
that enters the passenger compartment
through the air vents can be very hot or very
cold (depending on the set temperature).
This may cause burns or frostbite to unpro-
tected skin in the immediate area of the air
vents.
Always keep sufficient distance between un-
protected parts of the body and the air
vents. If necessary, use the air distribution
controls (
page 218) to direct the air to air
vents in the vehicle interior that are not in
the immediate area of unprotected skin.
Warning!G
Follow the recommended settings for heat-
ing and cooling given on the following pag-
es. Otherwise the windows could fog up,
impairing visibility and endangering you and
others.
iSevere conditions (e.g. strong air pollution)
may require replacement of the filter before its
scheduled interval. A clogged filter will reduce
the air volume to the interior.
If the vehicle interior is hot, ventilate the interior
before driving off, see “Summer opening fea-
ture” (
page 251). The climate control will then
adjust the interior temperature to the set value
much faster.
Keep the air intake grille in front of the wind-
shield free of snow and debris.

220 Controls in detail
Climate control
Deactivating the climate control
system
Deactivating
Press button´ (page 218).
The indicator lamp on the button
comes on.Reactivating
Press buttonU (page 218).
Operating the climate control system
in automatic modeActivating
Press buttonU (page 218) while
the engine is running.
The indicator lamp on the button
comes on. The air volume and air distri-
bution are adjusted automatically.
Use temperature controls1 and7
(
page 218) to separately adjust the
air temperature on each side of the
passenger compartment.
The interior air temperature is adjusted
automatically.
Deactivating
Press button
orQ
(
page 218).
The indicator lamp on buttonU
goes out. The automatic operation of
air volume switches off. The selected
blower speed is shown in the air
volume displayb (
page 218).
Warning!G
When the climate control system is
switched off, the outside air supply and cir-
culation are also switched off. Only choose
this settings for a short time. Otherwise the
windows could fog up, impairing visibility
and endangering you and others.
iYou can also press button´
(
page 218) on the climate control panel.
If you press button0 or, depending on vehi-
cle production date, button|(
page 218)
to reactivate the climate control system, the
defrosting mode is activated.
iWhen operating the climate control system
in automatic mode, you will only rarely need to
adjust the temperature, air volume and air distri-
bution.
In automatic mode, cooling with dehumidify is
switched on. This function can be switched off if
necessary (
page 227).
iThe settings for the passenger side are also
used for the rear passenger compartment.

226 Controls in detail
Climate control
Convenience closing
Press button: for approximately
2 seconds.
The windows and/or tilt/sliding sun-
roof* will close. You can release
button: once the closing proce-
dure has begun. The windows and
tilt/sliding sunroof* continue closing
until they are fully closed. The indicator
lamp on the button comes on. The air
recirculation mode is activated.Convenience opening
Press button: for approximately
2 seconds.
The windows and/or tilt/sliding sun-
roof* will return to their previous posi-
tions. You can release button:
once the opening procedure has be-
gun. The windows and tilt/sliding sun-
roof* continue opening until they have
reached their previous positions. The
indicator lamp on the button goes out.
The air recirculation mode is deactivat-
ed.
Air conditioning
The air conditioning is operational while
the engine is running and cools the interior
air to the temperature set by the operator.
In addition, the air conditioning dehumidi-
fies the interior air at outside temperatures
above 41°F (5° C) and helps prevent
window fogging.The closing of the windows and the
tilt/sliding sunroof* can be reversed by
again pressing and holding the :button.
iA window or the tilt/sliding sunroof* will
only return to its previous position if it has not
been moved to another position using the re-
spective window switch or tilt/sliding sunroof*
switch after it was closed with button:.
iCondensation may drip out from underneath
the vehicle. This is normal and not an indication
of a malfunction.
Warning!G
If you turn off the cooling function, the
interior air is not dried. The windows can fog
up more quickly. Window fogging may
impair visibility and endanger you and
others.