tow MERCEDES-BENZ GL320CDI 2007 X164 Owner's Guide

304 Controls in detail
Loading
The gross vehicle weight which is the
weight of the vehicle including fuel, tools,
spare wheel, installed accessories, pas-
sengers and luggage/cargo must never
exceed the load limit and Gross Vehicle
Weight Rating (GVWR) for your vehicle as
specified on the placard located on the
driver’s door B-pillar (
page 550). In addi-
tion, the load must be distributed in such a
way so that the weight on each axle never
exceeds the Gross Axle Weight Rating
(GAWR) for the front and rear axle. The
GVWR and GAWR for your vehicle are indi-
cated on the certification label which can
be found on the driver’s door B-pillar
(
page 550).
For more information, see “Tire and Load-
ing Information” (
page 389).
The handling characteristics of a fully load-
ed vehicle depend greatly on the load dis-
tribution. It is therefore recommended to
load the vehicle according to the illustra-
tions shown, with the heaviest items being
placed towards the front of the vehicle.Please pay attention to and comply with
the following instructions when loading the
vehicle and transporting cargo:

Always place items being carried
against front or rear seat backrests,
and fasten them as securely as possi-
ble.

The heaviest portion of the cargo
should always be kept as low as possi-
ble against front or rear seat backrests.
For additional safety when transporting
cargo while the rear seats are unoccupied,
fasten the outer seat belts crosswise into
the opposite side buckles.
Cargo tie-down rings
Your vehicle is equipped with eight cargo
tie-down rings.
Carefully secure cargo by applying even
load on all rings with rope of sufficient
strength to hold down the cargo.
iThe cargo compartment is the preferred
place to carry objects. The expanded cargo com-
partment (
page 306) should only be used for
items which do not fit in the cargo compartment
alone.
iWhile the cargo net* (page 313) will help
protect you from smaller objects, it cannot pre-
vent the movement of large, heavier objects into
the passenger compartment in an accident, dur-
ing hard braking or sudden maneuvers. Such
items must be properly secured using the cargo
tie-down rings in the cargo compartment floor.

336 Controls in detail
Useful features
Roadside Assistance button•
The Roadside Assistance button• is
located below the center armrest cover.
1Roadside Assistance button•
Open the storage tray (page 319).
Press and hold button1 (for longer
than 2 seconds).
A call to a Mercedes-Benz Roadside
Assistance dispatcher will be initiated.
The button will flash while the call is in
progress. The message
Connecting call will appear in the
multifunction display.When the connection is established, the
message
Call connected appears in the
multifunction display. The Tele Aid system
will transmit data generating the vehicle
identification number, model, color and
location (subject to availability of cellular
and GPS signals).
A voice connection between the Roadside
Assistance dispatcher and the occupants
of the vehicle will be established.
Describe the nature of the need for as-
sistance.The Mercedes-Benz Roadside Assistance
dispatcher will either dispatch a qualified
Mercedes-Benz technician or arrange to
tow your vehicle to the nearest
Mercedes-Benz Light Truck Center. For
services such as labor and/or towing,
charges may apply. Refer to the Roadside
Assistance Manual for more information.
The following is only available in the USA:

Sign and Drive services: Services such
as jump start, a few gallons of fuel or
the replacement of a flat tire with the
vehicle spare tire are obtainable.
iWhile the call is connected you can change
to the navigation menu by pressing the NAV
button on the COMAND system unit.

352 Operation
Driving instructions
Parking brake
When driving on wet roads or dirt covered
surfaces, road salt and/or dirt can get into
the parking brake. To prevent corrosion
and a reduction in the braking power of the
parking brake, observe the following:
From time to time, lightly engage the
parking brake before driving off.
Drive a distance of approximately
110 yds (100 m) at a maximum speed
of 12 mph (20 km/h).
Driving off
Apply the brakes to test them briefly after
driving off. Perform this procedure only
when the road is clear of other traffic.
Warm up the engine smoothly. Do not
place full load on the engine until the oper-
ating temperature has been reached.Parking
Warning!G
While performing this procedure, please
assure that the vehicle is stopped before
applying the parking brake. Otherwise the
rear wheels could lock up. You could lose
control of the vehicle and cause an accident.
In addition, the vehicle’s brake lights do not
light up when the parking brake is engaged.
Make sure not to endanger any other road
users when you engage the parking brake.
!When driving off on a slippery surface, do
not allow a drive wheel to spin for an extended
period with the ESP
® switched off. Doing so may
cause serious damage to the drivetrain which is
not covered by the Mercedes-Benz Limited
Warranty.
!Simultaneously depressing the accelerator
pedal and applying the brake reduces engine
performance and causes premature brake and
drivetrain wear.
Warning!G
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.
To reduce the risk of personal injury or
damage to the vehicle drivetrain as a result
of vehicle movement, before turning off the
engine and leaving the vehicle always:

Keep right foot on brake pedal.

Firmly depress parking brake pedal.

Set the automatic transmission to
positionP.

Slowly release brake pedal.

When parked on an incline, turn front
wheel towards the road curb.

353 Operation
Driving instructions
TiresTreadwear indicators (TWI) are required by
law. These indicators are located in six
places on the tread circumference and
become visible at a tread depth of
approximately
1/16in (1.6 mm), at which
point the tire is considered worn and
should be replaced.
The treadwear indicator appears as a solid
band across the tread.Specified tire inflation pressures must be
maintained. This applies particularly if the
tires are subjected to high loads (e.g. high
speeds, heavy loads, high ambient temper-
atures).
For more information, see “Tires and
wheels” (
page 385).

Turn the SmartKey or the SmartKey with
KEYLESS-GO* to starter switch
position0 and remove, or press
KEYLESS-GO* start/stop button.

Take the SmartKey or the SmartKey with
KEYLESS-GO* with you and lock vehicle
when leaving.
Warning!G
If you feel a sudden significant vibration or
ride disturbance, or you suspect that possi-
ble damage to your vehicle has occurred,
you should turn on the hazard warning flash-
ers, carefully slow down, and drive with cau-
tion to an area which is a safe distance from
the road.
Inspect the tires and the vehicle underbody
for possible damage. If the vehicle or tires
appear unsafe, have the vehicle towed to
the nearest Mercedes-Benz Light Truck
Center or tire dealer for repairs.
Warning!G
Although the applicable federal motor
vehicle safety laws consider a tire to be
worn when the treadwear indicators (TWI)
become visible at approximately
1/16in
(1.6 mm), we recommend that you do not
allow your tires to wear down to that level.
As tread depth approaches
1/8in (3 mm),
the adhesion properties on a wet road are
sharply reduced.
Depending upon the weather and/or road
surface (conditions), the tire traction varies
widely.
Warning!G
Do not drive with a flat tire. A flat tire affects
the ability to steer or brake the vehicle. You
may lose control of the vehicle. Continued
driving with a flat tire or driving at high
speed with a flat tire will cause excessive
heat build-up and possibly a fire.

359 Operation
Driving instructions
Checklist before off-road driving
Engine oil level

Check the engine oil level with the oil
dipstick (
page 381).
Only with a proper oil level can the
vehicle obtain a trouble-free oil supply,
even on steep gradients.Tires

Check the tread depth and maintain
specified tire inflation pressure
(a placard with the recommended tire
inflation pressures is located on the
driver’s door B-pillar (
page 389)).

Check tires for possible damage and
remove foreign objects.

Replace missing valve caps.
Rims

Dented or bent rims can cause tire in-
flation pressure loss and damage the
tire beads. For this reason, check and,
if necessary, change rims before driv-
ing off-road.
Vehicle tool kit

Check if the vehicle jack (page 497)
is functional.

In all cases take the vehicle tool kit, a
strong tow rope, a shovel and a small
plank (to put under the vehicle jack on
sandy soil) with you.

In sandy soil, drive at a steady speed as al-
lowed by conditions. This helps overcome
the vehicle rolling resistance and reduces
the likelihood of the vehicle sinking into the
ground.

Do not initiate jumps with the vehicle. It
interrupts the forward momentum of the
vehicle.

Always drive onto slopes with the engine
running and the vehicle in gear.

Do not shift automatic transmission to
positionN.
Warning!G
Do not reduce the tire inflation pressure
before driving through sand. However, if you
do so, remember to correct the tire inflation
pressure (
page 396) before continuing
your trip. Driving with reduced tire inflation
pressure increases the risk of losing control
of the vehicle and rolling over.
!If the engine oil level warning lamp
(
page 476) comes on while driving, stop the
vehicle in a safe location or as soon at is safe to
do so. Check the engine oil level (
page 381).
The engine oil level warnings should not be
ignored. Extended driving with the symbol
displayed could result in serious engine damage
that is not covered by the Mercedes-Benz
Limited Warranty.

361 Operation
Driving instructions
Traction in steep terrain
The maximum vehicle climbing ability is a
100% grade which is equivalent to a slope
angle of 45 degrees. Keep in mind that the
climbing ability of the vehicle depends on
terrain conditions.
Be easy on the accelerator and watch for
continuous wheel traction when driving in
steep terrain.Driving across a hilltop
Decelerate just ahead of a hilltop (do not
shift automatic transmission to
positionN), to prevent the vehicle from
speeding up too much after climbing a hill.
Use the momentum of the vehicle to drive
across the hilltop.
After climbing a hill, driving in this manner
prevents the vehicle from:

losing ground contact when cresting
hills

losing its forward momentum

speeding up too much after climbing
the hillDriving downhill

Drive slowly.

Do not drive at an angle to the incline.
Steer into the line of gravity and drive
with the front wheels pointing straight
downhill. Otherwise, the vehicle may
slide sideways off the path and roll
over.

Shift automatic transmission to
position1 (
page 200).

On steep inclines, use the Downhill
Speed Regulation (
page 275).

Utilize the engine’s braking power to
reduce vehicle speed.
If this is insufficient, apply the brake
gently. Make sure the vehicle is moving
in the line of gravity.

Check the brakes after a lengthy down-
grade drive.
iThe hill start assist system supports you
when driving uphill.
For more information, see “Hill start assist sys-
tem” (
page 199).
iThe 4-ETS helps greatly when starting out on
a steep incline when the front wheels have then
the tendency to slip due to the weight shifting
towards the rear axle.
The 4-ETS recognizes the situation and limits the
torque for the front wheels by braking them.
Simultaneously the torque for the rear wheels is
increased.
iVehicles with enhanced off-road package*
are equipped with automatic locks for the center
and rear axle differential to improve vehicle
traction.

365 Operation
Driving instructions
Returning from off-road drivingOff-road driving increases strain on the
vehicle.
We recommend that you inspect the vehi-
cle for possible damage after each off-road
trip. Recognizing any damage and a subse-
quent timely repair reduces the chance of
a possible breakdown or accident later on.
Proceed as follows:

Switch off the off-road driving program
(
page 280) or the LOW RANGE
mode* (
page 203).

Switch off the DSR (page 276).

Set the differential locks* to AUTO
(
page 207).

Lower the vehicle back to a level
suitable for road conditions, e.g. High-
way/High-speed level (
page 281).

Clean all exterior lamps and check for
possible damage.

Clean the front and rear license plate.

Remove excessive dirt from tires,
wheels, wheel housings, and under-
body.
For instance, after driving in mud, clean
the radiator, chassis, engine, brakes,
and wheels from extreme dirt using a
strong jet of water.

Check tires for possible damage.

Inspect vehicle underbody, oil pan,
brake hoses, etc., as well as vehicle un-
derbody for possible damage.

Check for brush or branches caught in
the underbody.

After continued operation in mud,
sand, water or other dirty conditions
clean the brake discs, wheels, brake
pads and check and clean axle joints.

Conduct a brake test.
Warning!G
If you feel a sudden significant vibration or
ride disturbance, or you suspect that possi-
ble damage to your vehicle has occurred,
you should turn on the hazard warning flash-
ers, carefully slow down, and drive with cau-
tion to an area which is a safe distance from
the roadway.
Inspect the tires and under the vehicle for
possible damage. If the vehicle or tires ap-
pear unsafe, have it towed to the nearest
Mercedes-Benz Light Truck Center or tire
dealer for repairs.
Damage to the vehicle may influence driving
comfort and pose the risk of accident to you
and other drivers.
!Brush or branches could increase the possi-
bility of a fire, as well as cut fuel and/or brake
lines, puncture rubber bellows of the axles or
drive shafts.

366 Operation
Driving instructions
Trailer towing Trailer hitch*

Only install a trailer hitch receiver ap-
proved for your vehicle.
For information on availability and in-
stallation, contact an authorized
Mercedes-Benz Light Truck Center.

The bumpers on your vehicle are not
designed for use with clamp-type hitch-
es.
Do not attach rental hitches or other
bumper-type hitches to them.

To reduce the possibility of damage, re-
move the hitch ball adaptor from the
receiver when not in use.Electrical connections
The vehicle is prewired to accept the
seven-wire harness included in the
Mercedes-Benz approved trailer hitch
receiver kit.
For further information, contact an autho-
rized Mercedes-Benz Light Truck Center.
Vehicle and trailer weights and ratings
Gross Vehicle Weight Rating (GVWR) is the
maximum permissible vehicle weight:
6944 lb (3150 kg).
Gross Vehicle Weight (GVW):
Comprises weight of vehicle including fuel,
tools, spare wheel, installed accessories,
passengers, cargo and trailer tongue. It
must never exceed the GVWR.
Warning!G
Failure to use proper equipment and driving
technique can result in a loss of vehicle con-
trol when towing a trailer.
Improper towing or failure to follow the in-
structions in this manual can result in vehi-
cle damage and/or serious personal injury.
Follow the guidelines below carefully to as-
sure safe trailer operation.
Contact an authorized Mercedes-Benz Light
Truck Center should you require an explana-
tion of information contained in this manual.
iA four-pole conversion plug is available from
your authorized Mercedes-Benz Light Truck
Center as a spare part.

367 Operation
Driving instructions
Gross Axle Weight Rating (GAWR) is the
maximum permissible axle weight:
The Gross Trailer Weight (GTW) is the
weight of the trailer plus the weight of all
cargo, equipment, luggage etc. loaded on
the trailer. The maximum permissible
gross trailer weight to be towed:
7500 lb (3402 kg).
Trailer Tongue Weight Rating (TWR) is the
maximum permissible weight on the trailer
tongue:
600 lb (272 kg) limit for Mercedes-Benz
approved hitch receiver.Loading a trailer

When loading a trailer, you should ob-
serve that neither the permissible GTW,
nor the GVWR are exceeded.
Maximum permissible values are listed
on the safety compliance certification
labels for the vehicle and for the trailer
to be towed.
The lowest value listed must be select-
ed when determining how the vehicle
and trailer are loaded.

The tongue weight at the hitch ball
must be added to the GVW to prevent
exceeding your Mercedes-Benz tow
vehicle’s rear GAWR.Checking weights of vehicle and trailer

To assure that the tow vehicle and trail-
er are in compliance with the maximum
permissible weight limits have the load-
ed rig (tow vehicle including driver, pas-
sengers and cargo, trailer fully loaded)
weighed on a commercial scale.

Check the vehicle’s front and rear
Gross Axle Weight (GAW), the Gross
Trailer Weight (GTW) and Tongue
Weight (TW).
The values as measures must not
exceed the weight limits listed under
“Vehicle and trailer weight and ratings”
(
page 366).
GL 320 CDI
Front3306 lb (1500 kg)
Rear3968 lb (1800 kg)
GL 450
Front3240 lb (1470 kg)
Rear3968 lb (1800 kg)
iWe recommend loading the trailer in such a
manner that it has a Tongue Weight (TW)
between 8% and 15% of the Gross Trailer Weight
(GTW).
iMaximum trailer weight ratings are calculat-
ed assuming the vehicle, plus driver. The weight
of other accessories, passengers and cargo will
reduce the maximum trailer weight and Tongue
Weight (TW) your vehicle can tow.

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.