2008 MERCEDES-BENZ GL550 headlamp

147 Controls in detail
Lighting
Push in the exterior lamp switch to first
stop.
The rear fog lamp switches off.
The yellow indicator lamp† in the
exterior lamp switch goes out.
The front fog lamps remain lit.
Combination switch
1High beam
2High beam flasherHigh beam
Turn the exterior lamp switch to
positionB (
page 143).
Push the combination switch in
direction of arrow1 to switch on the
high beam.
The high beam headlamp indicator
lampA in the instrument cluster
comes on (
page 26).
Pull the combination switch in direction
of arrow2 to its original position to
switch off the high beam.
The high beam headlamp indicator
lampA in the instrument cluster
goes out.
High beam flasher
Pull the combination switch briefly in
direction of arrow2.
Corner-illuminating front fog lamps*
The corner-illuminating front fog lamps im-
prove illumination of the area in the direc-
tion into which you are turning.
The corner-illuminating front fog lamps will
operate with the engine running and with

the exterior lamp switch in
positionB (
page 143)
or

the exterior lamp switch in
positionU (
page 143)
or

the daytime running lamp mode
activated (
page 145)
iThe corner-illuminating front fog lamps will
only come on in low ambient lighting conditions.
iIf you are driving faster than 25 mph
(40 km/h) or have the front fog lamps switched
on, the corner-illuminating function is not avail-
able.
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169 Controls in detail
Control system
The following settings and submenus are
available in the
Settings menu:Resetting all settings
You can reset the functions of all
submenus to the factory settings.
Press the reset button in the instru-
ment cluster (
page 152) for
approximately 3 seconds.
The request to press the reset button
once more to confirm appears in the
multifunction display.
Press the reset button once more.
The functions of all the submenus will
reset to factory settings.
FunctionPage
Resetting all settings169
Submenus in the settings menu170
Instrument cluster submenu172
Time/Date submenu174
Lighting submenu175
Vehicle submenu178
Comfort submenu*181
iThe settings you have changed will not be
reset unless you confirm the action by pressing
the reset button a second time.
After approximately 5 seconds, the
Settings
menu reappears in the multifunction display
(
page 168).
iFor safety reasons, the function
Lamp Circuit Headlamp in the Lighting
submenu cannot be reset while driving.
The following message appears in the multifunc-
tion display:
Settings
Cannot be
completely reset
to factory settings
while driving.
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175 Controls in detail
Control system
Lighting submenu
Access the
Lighting submenu via the
Settings menu. Use the Lighting
submenu to change the lamp and lighting
settings on your vehicle.
The following functions are available:
Setting daytime running lamp mode
(USA only)
Move the selection marker with
buttonæ orç to the
Lighting
submenu.
Press buttonj ork repeatedly
until the message
Lamp Circuit
Headlamp
appears in the multifunction
display.
The selection marker is on the current
setting.
Press buttonæ orç to select
manual operation (
Manual) or daytime
running lamp mode (
Constant).
With daytime running lamp mode activated
and the exterior lamp switch in
positionMorU, the low beam
headlamps are switched on when the
engine is running.In low ambient light conditions the
following lamps will switch on additionally:

Parking lamps

Tail lamps

License plate lamps

Side marker lamps
For more information on the daytime
running lamp mode, see “Lighting”
(
page 143).
FunctionPage
Setting daytime running lamp
mode (USA only)175
Setting locator lighting176
Setting night security illumination176
Setting interior lighting delayed
shut-off177
iThis function is not available in countries
where the daytime running lamp mode is
mandatory and therefore in a constant mode.
iFor safety reasons, changing the setting for
the daytime running lamp mode is not possible
while the vehicle is in motion. The following
message appears in the multifunction display:
Settings
can only be made
at a standstill.
For safety reasons, resetting to factory settings
(
page 169) while driving will not deactivate the
daytime running lamp mode.
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176 Controls in detail
Control system
Setting locator lighting
With the locator lighting feature activated,
the exterior lamp switch in positionU
(
page 143) and the interior lighting in au-
tomatic mode (
page 150), the following
lamps will switch on during darkness when
the vehicle is unlocked using buttonŒ
on the SmartKey or SmartKey with
KEYLESS-GO:

Parking lamps

Tail lamps

License plate lamps

Side marker lamps

Front fog lamps
The locator lighting switches off when the
driver’s door is opened.
If you do not open a door after unlocking
the vehicle with the SmartKey, the lamps
will switch off automatically after
approximately 40 seconds.
Move the selection marker with
buttonæ orç to the
Lighting
submenu.
Press buttonj ork repeatedly
until the message
Surround Lighting
Function
appears in the multifunction
display.
The selection marker is on the current
setting.
Press buttonæ orç to switch
the locator lighting function
On orOff.
Turn the exterior lamp switch to
positionU when exiting the vehicle.
The locator lighting feature is
activated.Setting night security illumination
(Headlamps delayed shut-off)
Use this function to set whether you would
like the exterior lamps to remain on for
15 seconds during darkness after exiting
the vehicle and closing all doors.
With the headlamps delayed shut-off
feature activated and the exterior lamp
switch in positionU before the engine
is turned off, the following lamps will
switch on when the engine is turned off:

Parking lamps

Tail lamps

License plate lamps

Side marker lamps

Front fog lamps
If after turning off the engine you do not
open a door or do not close an opened
door, the lamps will automatically switch
off after 60 seconds.
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177 Controls in detail
Control system
Move the selection marker with
buttonæ orç to the
Lighting
submenu.
Press buttonj ork repeatedly
until the message
Headlamp Delayed
Shut-off
appears in the multifunction
display.
The selection marker is on the current
setting.
Press buttonæ orç to switch
the headlamps delayed shut-off feature
On or Off.
Turn the exterior lamp switch to
positionU before turning off the
engine.
The headlamps delayed shut-off
feature is activated.
You can temporarily deactivate the
headlamps delayed shut-off feature:
Before exiting the vehicle, turn the
SmartKey in the starter switch to
position0.
Then turn it to position2 and back
to0.
The headlamps delayed shut-off
feature is deactivated. It will reactivate
as soon as you reinsert the SmartKey in
the starter switch.
Vehicles with KEYLESS-GO*:
Press KEYLESS-GO start/stop button
in the starter switch (
page 43).Setting interior lighting delayed shut-off
Use this function to set whether you would
like the interior lighting to remain on for
10 seconds during darkness after you have
removed the SmartKey from the starter
switch.
Move the selection marker with
buttonæ orç to the
Lighting
submenu.
Press buttonj ork repeatedly
until the message
Interior Lighting
Delayed Shut-off
appears in the
multifunction display.
The selection marker is on the current
setting.
Press buttonæ orç to switch
the interior lighting delayed shut-off
feature
On orOff.
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208 Controls in detail
Good visibility
For information on windshield wipers, see
“Windshield wipers” (
page 62).
Headlamp cleaning system*
The headlamps will automatically be
cleaned with a high-pressure water jet
when you have

switched on the headlamps
and

operated the windshield wipers with
windshield washer fluid five times
When you switch off the headlamps, the
counter resets.
For information on filling up the washer
reservoir, see “Windshield/rear window
washer system and headlamp cleaning
system*” (
page 383).
Rear view mirrors
For more information on setting the rear
view mirrors, see “Mirrors” (
page 51).
Interior rear view mirror, antiglare
position
1Lever
Tilt the mirror to the antiglare position
by moving lever1 towards the wind-
shield.
The interior rear view mirror is dimmed.Auto-dimming rear view mirrors*
The reflection brightness of the exterior
rear view mirror on the driver’s side and
the interior rear view mirror will respond
automatically to glare when

the ignition is switched on
and

incoming light from headlamps falls on
the sensor in the interior rear view
mirror
The rear view mirror will not react if

the automatic transmission is set to
positionR

the interior lighting is turned on
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376 Operation
At the gas station
Low outside temperatures
(diesel engine)
To prevent malfunctions, diesel fuel with
improved cold flow characteristics is of-
fered in the winter months. Check with
your fuel retailer.Check regularly and before a long trip
Open the hood (page 378).
Example illustration GL 450 (GL 320 CDI,
GL 550 similar)
1Brake fluid
2Coolant level
3Windshield washer system and
headlamp cleaning system*
Engine oil level
For more information on engine oil, see
“Engine oil” (
page 380).
iDiesel engine:
If you have driven the vehicle until the tank is
empty, the fuel system needs to be bled
(
page 527).
!Diesel engine:
The engine is more susceptible to wear and
damage if you use

marine diesel fuel

heating oil

additives
The exhaust aftertreatment device will be
seriously damaged if you use

LOW SULFUR HIGHWAY DIESEL FUEL
(500 ppm SULFUR MAXIMUM)

any other diesel fuel with a sulfur content of
above 15 ppm
The use of such non-approved fuels and/or
special additives is not covered by the
Mercedes-Benz Limited Warranty.
!Do not fill the tank with gasoline. Do not
blend diesel fuel with gasoline or kerosine. The
fuel system and engine will otherwise be dam-
aged, which is not covered by the
Mercedes-Benz Limited Warranty.

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377 Operation
At the gas station
Brake fluid
Coolant
For normal replenishing, use water (pota-
ble water quality).
For more information, see “Coolant level”
(
page 381) and see “Fuels, coolants, lu-
bricants” (
page 562).Windshield/rear window washer
system and headlamp cleaning
system*
For more information on refilling the wash-
er reservoir, see “Windshield/rear window
washer system and headlamp cleaning
system*” (
page 383).
Vehicle lighting
Check function and cleanliness. For infor-
mation on replacing light bulbs, see “Re-
placing bulbs” (
page 504).
For more information, see “Exterior lamp
switch” (
page 143).
Tire inflation pressure
For more information, see “Checking tire
inflation pressure” (
page 395).
!If you find that the brake fluid in the brake
fluid reservoir has fallen to the minimum mark or
below, have the brake system checked for brake
pad thickness and leaks immediately. Notify an
authorized Mercedes-Benz Light Truck Center
immediately. Do not add brake fluid as this will
not solve the problem. For more information, see
“Brake fluid” (
page 564).
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