2007 MERCEDES-BENZ GL320CDI diff

183 Controls in detail
Control system
Drive a full circle at a vehicle speed of
between 3 mph and 6 mph (5 km/h
and 10 km/h).
When calibration was successful, the
following message appears in the mul-
tifunction display:
Compass calibration
Completed successfully
Audio search function
Use of the Audio search function to select
a radio station will enable you to start a
frequency scan (
Freq.) (page 166) or
select a radio station stored in memory
(
Memory).
Move the selection marker with
buttonæ orç to the
Vehicle
submenu.
Press buttonj ork repeatedly
until the message
Audio Search
function
appears in the multifunction
display.
The selection marker is on the current
setting.
Press buttonæ orç to select
Freq. or Memory.Setting automatic locking
Use this function to activate or deactivate
the automatic central locking. With the
automatic central locking system
activated, the vehicle is centrally locked at
vehicle speeds of approximately 9 mph
(15 km/h).
Move the selection marker with
buttonæ orç to the
Vehicle
submenu.
Press buttonj ork repeatedly
until the message
Automatic door
lock
appears in the multifunction
display.
The selection marker is on the current
setting.
Press buttonæ orç to switch
the automatic central locking
On or Off.
iIf the message Compass calibration
Completed successfully
does not appear in
the multifunction display, drive another full
circle.
If calibration does not succeed within 3 minutes,
the message
Compass Calibration appears
in the multifunction display again. Calibrating the
compass has failed due to outside influences.
Repeat compass calibration in a different
location.

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.

207 Controls in detail
Differential locks*
at the same speed, independent of the in-
dividual torque. Please be aware that en-
gaging the differential locks will
significantly reduce the steering ability of
the vehicle.
For your safety and the safety of others
and to prevent damage to the vehicle, the
differential locks must not be engaged
when driving on paved roads. It is impor-
tant to understand that during
on-road/paved driving, differentials are
absolutely necessary for providing the es-
sential control and steering ability of the
vehicle. The differential locks, therefore,
must not be engaged when driving on
paved roads and should only be used to
the extent necessary to negotiate off-road
conditions which cannot be handled by the
systems (automatic 4-ETS, the ESP
®, man-
ual switch position “LOW” of transfer case)
this vehicle comes equipped with.
Switching differential locks*The rotary switch for the differential locks
is located on the upper part of the center
console.
You can select between three locking
modes.
1Rotatable outer adjustment ring with
indicator lamp
2AUTO mode: center differential is auto-
matically locked
3Center differential is completely locked
4Center and rear axle differential are
completely locked
!If the differential locks are engaged, accel-
erate gently when setting the vehicle in motion.
To avoid damage to the transmission, the vehicle
may only be operated on a dynamometer (single
axle dynamometer) if

the axle not being driven is jacked up
or

the associated propeller shaft is disconnect-
ed.

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.

262 Controls in detail
Driving systems
Setting to last stored speed
(“Resume” function)
Briefly pull the cruise control lever in di-
rection of arrow4 (
page 258).
The cruise control resumes to the last
set speed, or if no speed is stored, it
will set and store the current speed.
Remove your foot from the accelerator
pedal.
The last set speed appears in the multi-
function display for approximately
5 seconds.
Distronic*
When activated, the Distronic adaptive
cruise control system increases the driving
convenience afforded by the cruise control
while traveling on expressways and other
major roadways.

If the Distronic distance sensor detects
a slower moving vehicle directly ahead,
your vehicle speed will be reduced so
that you follow that vehicle at your
preset following distance.

If there is no vehicle directly ahead of
you, Distronic will function in the same
way as standard cruise control
(
page 257).
Warning!G
The set speed stored in memory should only
be set again if prevailing road conditions
permit. Possible acceleration or decelera-
tion differences arising from returning to the
preset speed could cause an accident
and/or serious injury to you and others.
Warning!G
Distronic is a convenience system. Its speed
adjustment reduction capability is intended
to make cruise control more effective and
usable when traffic speeds vary. It is not
however, intended to, nor does it, replace
the need for extreme care. The responsibili-
ty for the vehicle’s speed, distance to the
preceding vehicle and, most importantly,
brake operation to ensure a safe stopping
distance, always remains with the driver.
Distronic cannot take road and traffic condi-
tions into account.
Complex driving situations are not always
fully recognized by Distronic. This could
result in wrong or missing distance
warnings.

265 Controls in detail
Driving systems
Distronic displays in the speedometer
dial
1Set speed
If Distronic is activated, one or two cruise
control speed segments come on around
the set speed.1Set speed
2Cruise control speed segments
3Speed of the vehicle ahead
If Distronic detects a vehicle directly
ahead, the cruise control speed
segments2, which represents the differ-
ence from the speed of the preceding
vehicle3 to the driver’s selected set
speed1, appear in the speedometer.If Distronic calculates that there is a dan-
ger of collision:

The distance warning lampl in the
instrument cluster comes on
(
page 27).

An intermittent warning sounds.
Immediately apply the brake to avoid a
collision.
Under no circumstances should the
driver await the intermittent warning
sound before braking. See the follow-
ing warning note.
The intermittent warning sound ceases
and the distance warning lampl
goes out when the necessary distance
to the vehicle ahead is again estab-
lished.
iThe vehicle speed displayed on the speed-
ometer can briefly vary from the speed setting
on the Distronic system.

270 Controls in detail
Driving systems
Adjustment in 5 mph
(Canada: 10 km/h) increments
Briefly press the cruise control lever
down past the resistance point in direc-
tion of arrow2 (
page 267).
Release the cruise control lever.
The vehicle set speed decreases in
increments of 5 mph
(Canada: 10 km/h).Setting to last stored speed
(“Resume” function)
Briefly pull the cruise control lever in
direction of arrow4 (
page 267).
The Distronic resumes to the last set
speed.
Remove your foot from the accelerator
pedal.
The last set speed or, if no speed is stored,
the current set speed appears in the
multifunction display for approximately
5 seconds.Deactivating Distronic
There are several ways to deactivate the
Distronic system:
Step on the brake pedal.
or
Briefly tip the cruise control lever in
direction of arrow3 (
page 267).
Distronic will be deactivated. The last set
speed will be stored in memory.
iThe set speed value is decreased in 5 mph
(Canada: 10 km/h) increments each time you
press the cruise control lever down past the
resistance point.
iThe new speed is set and the vehicle will
decelerate. Keep in mind that it may take a brief
moment until the vehicle has reached the set
speed.
Warning!G
The set speed stored in memory should only
be set again if prevailing road conditions
permit. Possible acceleration or decelera-
tion differences arising from returning to the
preset speed could cause an accident
and/or serious injury to you and others.
iThe following message appears in the multi-
function display for approximately 5 seconds:
DISTRONIC Off.
The last stored set speed is deleted when the
engine is turned off.