2008 MERCEDES-BENZ GL450 bumper

154 Controls in detail
Instrument cluster
The temperature sensor is located in the
front bumper area. Due to its location, the
sensor can be affected by road or engine
heat during idling or slow driving. This
means that the accuracy of the displayed
temperature can only be verified by com-
parison to a thermometer placed next to
the sensor, not by comparison to external
displays (e.g. bank signs etc.).
When moving the vehicle into colder ambi-
ent temperatures (e.g. when leaving your
garage), you will notice a delay before the
lower temperature is displayed.
A delay also occurs when ambient temper-
atures rise. This prevents inaccurate tem-
perature indications caused by heat
radiated from the engine during idling or
slow driving.
164.boo Seite 154 Freitag, 30. März 2007 12:54 12

289 Controls in detail
Driving systems
The Parktronic system deactivates at
vehicle speeds exceeding approximately
11 mph (18 km/h). At lower vehicle
speeds the Parktronic system turns on
again.
The Parktronic system also deactivates
when you set the automatic transmission
to positionP or depress the parking brake
pedal.
The Parktronic system monitors the sur-
roundings of your vehicle with six sensors
in the front bumper and four sensors in the
rear bumper.
1Sensors in the front bumperRange of the sensors
To function properly, the sensors must be
free of dirt, ice, snow and slush. Clean the
sensors regularly, being careful not to
scratch or damaging the sensors, see
“Cleaning the Parktronic* system sensors”
(
page 430).
!During parking maneuvers, pay special
attention to objects located above or below the
height of the sensors (e.g. planters or trailer
hitches). The Parktronic system will not detect
such objects at close range and damage to your
vehicle or the object may result.
Ultrasonic signals from outside sources (e.g.
working jackhammers, car wash or the air brakes
of trucks) may impair the operation of the
Parktronic system.
164.boo Seite 289 Freitag, 30. März 2007 12:54 12

293 Controls in detail
Driving systems
Rear view camera*
Warning!G
The rear view camera is only an aid and may
display obstacles from a distorted perspec-
tive or inaccurately, or may not display ob-
stacles at all. The rear view camera does not
relieve you of the responsibility to be cau-
tious, take care and pay careful attention.
The rear view camera may not show objects
which are:

very close to the rear bumper

under the rear bumper

above the tailgate handle
You are responsible for safety at all times
and must continue to pay attention to the
immediate surroundings when parking and
maneuvering. This includes the area behind,
in front of and beside the vehicle. Otherwise
you could endanger yourself or others.
Warning!G
Make sure that no persons or animals are in
or near the area in which you are
parking/maneuvering. Otherwise, they
could be injured.
Warning!G
The rear view camera either will not function
or will not function to its full capability if:

the tailgate is open

it is raining very hard, snowing or foggy

it is night or you are parking/maneuver-
ing your vehicle in an area where it is
very dark

the camera is exposed to a very bright
white light

the immediate surroundings are illumi-
nated with fluorescent light (the display
may flicker)

there is a sudden change in tempera-
ture, e.g. if you drive into a heated ga-
rage from the cold (lens condensation)

the camera lens is dirty or covered

the rear of your vehicle is damaged
In this case, have the position and set-
ting of the camera checked by a quali-
fied specialist workshop.
Mercedes-Benz recommends that you
visit a Mercedes-Benz Light Truck
Center for this purpose.
Do not use the rear view camera in these sit-
uations. Otherwise you could injure yourself
or others and/or damage property including
your vehicle while parking/maneuvering.
164.boo Seite 293 Freitag, 30. März 2007 12:54 12

364 Operation
Driving instructions

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.
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.
!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.
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.
164.boo Seite 364 Freitag, 30. März 2007 12:54 12

366 Operation
Driving instructions
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 365).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.
Make sure to leave enough slack in 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.
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 279) or the vehicle level
control system (
page 279) when cou-
pling/decoupling the trailer.
164.boo Seite 366 Freitag, 30. März 2007 12:54 12

430 Operation
Vehicle care
Cleaning the Distronic* system sensor
cover
1Distronic* system sensor cover
Switch off the ignition (page 42).
Use a mild car wash detergent, such as
Mercedes-Benz approved Car Sham-
poo, with plenty of water and a
non-scratching cloth to clean sensor
cover1.
Restart the engine after cleaning sen-
sor cover1.
Cleaning the Parktronic* system
sensors
1Parktronic* system sensors in front
bumper
Use a mild car wash detergent, such as
Mercedes-Benz approved Car Sham-
poo, with plenty of water and a soft,
non-scratching cloth to clean
sensors1 on the bumpers.
!To prevent scratches or damage, never
apply strong force and only use a soft,
non-scratchy cloth when cleaning the sensor
cover1. Do not attempt to wipe dirty sensors
with a dry cloth or sponge.
!Do not apply strong pressure to the sensor
covers. Applying strong pressure may damage
the sensor covers.
Follow the instructions provided by the power
washer manufacturer on maintaining a distance
between the vehicle and the nozzle of the power
washer.
!To prevent scratches, never apply strong
force and only use a soft, non-scratching cloth
when cleaning the sensors. Do not attempt to
wipe dirty sensors with a dry cloth or sponge.
164.boo Seite 430 Freitag, 30. März 2007 12:54 12

510 Practical hints
Replacing bulbs
Side marker lamp bulb
Turn bulb socket5 (page 507)
counterclockwise.
Pull bulb socket5 out of the
headlamp housing.
Pull the side marker bulb out of bulb
socket5.
Insert the new side marker bulb into
bulb socket5.
Insert bulb socket5 into the
headlamp housing.
Turn bulb socket5 clockwise until it
engages.Front fog lamp bulbs
Removing front fog lamp cover:
1Cover
2Front fog lamp or corner-illuminating
front fog lamp*
Insert a suitable object (e.g. screwdriv-
er) at point indicated by the arrow and
pry out cover1.
Cover1 is released.
Swing cover1 outwards and take it
off.
You can now access the front fog lamp.
3Retaining screws
Turn retaining screws3 counterclock-
wise.
Remove front fog lamp2 out of the
bumper.
Pull electrical connector off.
!If not done carefully and properly, damage
to the bumper can result. We therefore recom-
mend that you have this work carried out by an
authorized Mercedes-Benz Light Truck Center.
164.boo Seite 510 Freitag, 30. März 2007 12:54 12

511 Practical hints
Replacing bulbs
4Bulb socket of front fog lamp bulb
Turn bulb socket4 counterclockwise.
Pull bulb socket4 out of the housing.
Pull the front fog lamp bulb out of bulb
socket4.
Insert the new front fog lamp bulb into
bulb socket4.
Insert bulb socket4 into the housing.
Turn bulb socket4 clockwise until it
engages.
Plug in the electrical connector.
Insert front fog lamp2 back into
bumper.
Fasten retaining screws3.
Reinsert cover1 and press it in until it
engages.
Additional turn signal lamps bulbs
The additional turn signal lamps in the
exterior rear view mirrors have LEDs.
If a malfunction occurs or LEDs fail to func-
tion, the entire turn signal unit must be re-
placed. Have the turn signal unit replaced
by an authorized Mercedes-Benz Light
Truck Center.
Replacing bulbs for rear lamps
Before you start to replace a bulb for a rear
lamp, do the following first:
Turn the exterior lamp switch to
positionM (
page 143).
Tail lamp unit
Open the tailgate (page 122).
iTo access the bulb socket, you have to
remove the cover in the corresponding side trim
panel of the cargo compartment.
164.boo Seite 511 Freitag, 30. März 2007 12:54 12