2007 MERCEDES-BENZ GL320CDI tailgate

358 Operation
Driving instructions
Special driving features for off-road
driving
The following driving features are available
for specific kind of operation:

Off-road – ABS (page 104)

Off-road – ESP® (page 108)

Off-road – 4-ETS (page 110)

Hill start assist system (page 199)

LOW RANGE mode* (page 203)

Differential locks* (page 206)

Downhill Speed Regulation (DSR)
(
page 275)

Off-road driving program (Vehicles
without enhanced off-road package*)
(
page 279)

Air suspension (page 280)Off-road driving rules

Engage the off-road driving program
(
page 279) or LOW RANGE mode*
(
page 203) before driving under
off-road conditions.

If necessary, activate differential
locks* (
page 206).

Make sure you select a vehicle level
(
page 281) appropriate to the topo-
graphical conditions. Always make
sure the vehicle has enough ground
clearance.

Fasten items being carried as securely
as possible (
page 297).

Always navigate gradients with the en-
gine on and with the transmission en-
gaged in a gear. Switch on the DSR
(
page 276) to help maintain a preset
speed.
!Observe the following during off-road
driving:

Keep doors, tailgate, windows, and
tilt/sliding sunroof* closed whenever driving
off-road.

Adjust vehicle speed to condition of terrain.
The more uneven, rutty and steeper the ter-
rain, the lower the speed should be. Drive
through water slowly at an even speed,
avoiding a bow wave.

Be especially careful when driving in un-
known territory. It may be necessary to get
out of the vehicle and scout the path you in-
tend to take.

Watch out for obstacles, such as rocks,
holes, tree stumps and ruts.

Before driving through water, determine its
depth.

Do not stop vehicle while immersed in water,
and do not shut off the engine.

368 Operation
Driving instructions
Attaching a trailerObserve maximum permitted trailer
dimensions (width and length).
Most states and all Canadian provinces
require

safety chains between your tow vehicle
and the trailer.
The chains should be criss-crossed
under the trailer tongue. They must be
attached to the hitch receiver, and not
to the vehicle’s bumper or axle.
Ma ke sur e to l ea ve e nough s la ck i n the
chains to permit turning corners.

a separate brake system at various
trailer weights.

a break-away switch on trailers with a
separate brake system. Check with
your local state laws for specific
requirements.
The switch activates the trailer brakes
in the possible event that the trailer
might separate from the tow vehicle.
Make sure the automatic transmission
is set toP (
page 194).
Set the parking brake for the vehicle
(
page 68).
Start the engine (page 57).
Set the vehicle level to Highway
(
page 281).
Vehicle with ADS*: Set the ADS* to
AUTO or COMFORT (
page 280).
Turn off the engine (page 69).
Warning!G
While you are coupling or decoupling a trail-
er, make sure that you do not

lock or unlock

open or close
a vehicle door or the tailgate.
The vehicle’s level could change and you
could endanger yourself and/or others as a
result.
Make sure that you do not operate the ADS
button* (
page 281) or the vehicle level
control system (
page 281) when cou-
pling/decoupling the trailer.
!Do not connect a trailer brake system (if
trailer is so equipped) directly to the vehicle’s
hydraulic brake system, as your vehicle is
equipped with antilock brakes. If you do, neither
the vehicle’s brakes nor the trailer’s brakes will
function properly.
iThe provided vehicle electrical connector for
trailer towing has a brake signal wire for hook-up
to a brake controller.
You should consider using a trailer sway control
system. For further information, contact an
authorized Mercedes-Benz Light Truck Center.

369 Operation
Driving instructions
Close all doors and the tailgate.
Attach the trailer.
Plug in all electrical connectors.
Towing a trailer
There are many different laws, including
speed limit restrictions, having to do with
trailer towing. Make sure your rig will be le-
gal, not only for where you reside, but also
for where you will be driving. A good
source for this information can be the po-
lice or local authorities.Note the following points, when driving
with the trailer:
In order to gain skill and an understand-
ing of the vehicle’s behavior, you
should practice turning, stopping and
backing up in an area which is free from
traffic.

Before you start driving check the

trailer hitch

break-away switch

safety chains

electrical connections

lighting and tires

Adjust the mirrors (page 52) to
permit unobstructed view beyond rear
of trailer.

If the trailer has electric brakes, start
your vehicle and trailer moving slowly,
and then apply only the trailer brake
controller by hand to make sure the
brakes are working properly.

Always secure items in the trailer to
prevent load shifts while driving.

When towing a trailer, check occasion-
ally to make sure the load is secure,
and that lighting and trailer brakes (if
so equipped) are functioning properly.

Take into consideration that when tow-
ing a trailer, the handling characteris-
tics are different and less stable from
those when operating the vehicle with-
out a trailer.
It is important to avoid sudden maneu-
vers.

The vehicle and trailer combination is
heavier, and therefore is limited in ac-
celeration and climbing ability, and re-
quires longer stopping distances.
It is more prone to reacting to cross
wind gusts, and requires more sensi-
tive steering input.

If possible, do not brake abruptly, but
rather engage the brake slightly at first
to permit the trailer to activate its
brake. Then increase the braking force.
iWhen you are towing a trailer, the vehicle
level always remains in the Highway setting.
The following applies additionally when towing a
trailer:

The vehicle is lowered to the highway level
when it reaches a speed of 5 mph (8 km/h)
if not set to highway level.

The high-speed level is not available.
The restrictions that apply to towing also apply
when using accessories that are connected to
the trailer power socket, such as a bicycle rack.

370 Operation
Driving instructions

If the transmission repeatedly shifts
between gears on inclines, manually
shift to a lower gear (select 4, 3, 2 or 1)
(
page 200).
A lower gear and reduction of speed re-
duces the chance of engine overload-
ing and/or overheating.

On very steep inclines, not manageable
with automatic transmission in1,
switch on off-road driving program
(
page 280) or LOW RANGE mode*
(
page 203).

When going down a long hill, shift into
a lower gear and use the engine’s brak-
ing effect.
Avoid riding the brakes, thus overheat-
ing the vehicle and trailer brakes.

If the engine coolant rises to an ex-
tremely high temperature (coolant tem-
perature needle approaching the red
zone) when the air conditioning is on,
turn off the air conditioning system.
Engine coolant heat can be additionally
vented by opening the windows,
switching the climate control fan speed
to high and setting the temperature
control to the maximum hot position.

Extreme care must be exercised since
your vehicle with a trailer will require
additional passing distance ahead than
when driving without a trailer.
Because your vehicle and trailer is
longer than your vehicle alone, you will
also need to go much farther ahead of
the passed vehicle before you can re-
turn to your lane.Uncoupling the trailer
!If the trailer should begin to sway, reduce
the vehicle’s speed immediately.
In no case attempt to straighten out the tow
vehicle and trailer by increasing the speed.
Warning!G
While you are coupling or decoupling a trail-
er, make sure that you do not

lock or unlock

open or close
a vehicle door or the tailgate.
The vehicle’s level could change and you
could endanger yourself and/or others as a
result.
Make sure that you do not operate the ADS
button* (
page 281) or the vehicle level
control system (
page 281) when cou-
pling/decoupling the trailer.

371 Operation
Driving instructions
Make sure the automatic transmission
is set toP (
page 194).
Set the parking brake for the vehicle
(
page 68).
Start the engine (page 57).
Close all doors and the tailgate.
Set the parking brake for the trailer.
Disconnect all electrical plug connec-
tors.
Uncouple the trailer.
Make sure that the trailer coupling is
free of load.
Turn off the engine (page 69).
Passenger compartment
Warning!G
As soon as you disconnect the electrical
connection between the trailer and the
vehicle, the vehicle will lower. To help avoid
personal injury, make sure no one is near
the wheel housing or underneath the vehicle
before the electrical connection is discon-
nected.
When you uncouple the trailer, the vehicle is
temporarily raised because the springs are
relieved of load. Be especially careful during
this process, as you could otherwise injure
yourself and/or others. Make sure that any
persons remaining in the vehicle do not
press the switches for vehicle level control
or the ADS*.
Warning!G
Always fasten items being carried as secure-
ly as possible.
In an accident, during hard braking or sud-
den maneuvers, loose items will be thrown
around inside the vehicle, and cause injury
to vehicle occupants unless the items are
securely fastened in the vehicle.
The rear cargo compartment is the preferred
place to carry objects. Always use tie down
rings, and if so equipped, always use the
cargo net* when transporting cargo. The
cargo net* cannot secure hard or heavy ob-
jects. Always fasten items being carried as
securely as possible using the cargo
tie-down rings in the cargo floor area and
fastening materials.

478 Practical hints
What to do if …
Display symbolDisplay messagesPossible cause/consequencePossible solution
c You are driving with one or more
doors open.Stop the vehicle in a safe location or as
soon as it is safe to do so.
Close the door(s).
AGas cap is openA loss of pressure has been
detected in the fuel system. The
fuel cap may not be closed
properly or the fuel system may
be leaky.Check the fuel cap (page 375).
If it is not closed properly:
Close the fuel cap.
If it is closed properly:
Have the fuel system checked by an
authorized Mercedes-Benz Light Truck
Center.
aYou are driving with the hood or
the tailgate open.Carefully bring the vehicle to a halt as
soon as it is safe to do so in a safe
location.
Close the hood (page 380) or the
tailgate (
page 125).
You are trying to lock the vehicle
with the KEYLESS-GO* function
with a door or the tailgate open.Close all doors and/or the tailgate
(
page 125).

490 Practical hints
What to do if …
Display symbolDisplay messagesPossible cause/consequencePossible solution
nLevel selection
not permittedYou are driving too fast for the desired
vehicle level.Reduce vehicle speed.
Set the desired vehicle level again
(
page 281).
You are towing a trailer or using acces-
sories that are connected to the trailer
power socket, e.g. a bicycle rack.
Leveling cancelledYou have selected another vehicle
level*.
pReduce speed to
under 20 mphYou are driving too fast for the set vehi-
cle level.Do not drive faster than 20 mph
(30 km/h).
Visit workshopThe air suspension functional only to a
limited extent.Do not drive faster than 50 mph
(80 km/h) depending on the set
vehicle level.
Have the vehicle checked at an au-
thorized Mercedes-Benz Light
Truck Center.
Door open
Veh. lowering canceledYou have opened a door or the tailgate
while the vehicle is being lowered.

495 Practical hints
Where will I find ...?
Where will I find ...?
First aid kit
The first aid kit is located on the driver’s
side in the cargo compartment behind the
cover.
1Lock
2Cover in left side trim panel
Turn lock1 90° in direction of arrow.
Fold down cover2.
The first aid kit can be removed.
Vehicle tool kit
The vehicle tool kit is stored under the
cargo compartment floor.
The vehicle tool kit includes:

Towing eye bolt

Wheel wrench

Alignment bolt

Vehicle jack

Fuse chart

Spare fuses

Fuse extractor

Collapsible wheel chock

Wheel bolts for spare wheel1Cargo compartment floor, lowered
2Handle cover
Open the tailgate (page 124).
Push in handle cover2 as indicated
by arrow and pull handle.
Lift cargo compartment floor1.
iCheck expiration dates and contents for
completeness at least once a year and replace
missing/expired items.