2008 MERCEDES-BENZ GL550 high beam

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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450 Practical hints
What to do if …
On the pages that follow, you will find a
compilation of the most important warning
and malfunction messages that may
appear in the multifunction display.
For your convenience the messages are
divided into two sections:

Text messages (page 451)

Symbol messages (page 466)
Warning!G
No messages will be displayed if either the
instrument cluster or the multifunction
display is inoperative.
As a result, you will not be able to see infor-
mation about your driving conditions, such
as speed or outside temperature, warn-
ing/indicator lamps, malfunction/warning
messages or the failure of any systems.
Driving characteristics may be impaired.
If you must continue to drive, please do so
with added caution. Visit an authorized
Mercedes-Benz Light Truck Center as soon
as possible.
iSwitching on the ignition causes all
instrument cluster lamps (except high beam
headlamp indicator lamp, and turn signal
indicator lamps unless activated) as well as the
multifunction display to come on. Make sure the
lamps and multifunction display are in working
order before starting your journey.
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478 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
. Cornering Lamp
LeftThe left corner-illuminating front
fog lamp is malfunctioning.Replace the bulb as soon as possible
(
page 510).
Cornering Lamp
RightThe right corner-illuminating
front fog lamp is malfunctioning.Replace the bulb as soon as possible
(
page 510).
Front Foglamp
LeftThe left front fog lamp is
malfunctioning.Replace the bulb as soon as possible
(
page 510).
Front Foglamp
RightThe right front fog lamp is
malfunctioning.Replace the bulb as soon as possible
(
page 510).
High Beam
LeftThe left high beam lamp is
malfunctioning.Halogen headlamp:
Replace the bulb as soon as possible
(
page 508).
Bi-Xenon* headlamp:
Contact an authorized Mercedes-Benz
Light Truck Center as soon as possible.
High Beam
RightThe right high beam lamp is
malfunctioning.Halogen headlamp:
Replace the bulb as soon as possible
(
page 508).
Bi-Xenon* headlamp:
Contact an authorized Mercedes-Benz
Light Truck Center as soon as possible.
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505 Practical hints
Replacing bulbs
Front lamps
Rear lamps
LampType
1Parking and standing
lampW5W
2Headlamps:
High beam/high beam
flasher
H7 (55 W)
Bi-Xenon headlamps*:
High beam/high beam
flasher spot lamp
H7 (55 W)
3Headlamps:
Low beam
H7 (55 W)
Bi-Xenon headlamps*:
Low beam1
1Vehicles with Bi-Xenon* headlamps: Do not re-
place the Bi-Xenon bulbs yourself. Contact an
authorized Mercedes-Benz Light Truck Center.
D1S-35 W
4Additional turn signal
lampLED
5Side marker lampWY 5 W
LampType
6Turn signal lamp3457 AK
S-8
(30/2.2 cp
bulb)
7Front fog lampH11 (55 W)
Corner-illuminating
front fog lamp*
H11 (55 W)
LampType
8High mounted brake
lamp
LED
9Backup lampP21W
aTail, brake, parking,
standing, side marker
lampP21/4W
bTurn signal lampPY 21 W
cRear fog lamp (driver’s
side only)P21/4W
dLicense plate lampsC5W
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506 Practical hints
Replacing bulbs
Notes on bulb replacement

Only use 12-volt bulbs of the same type
and with the specified watt rating.

Switch lights off before changing a bulb
to prevent short circuits.

Always use a clean lint-free cloth when
handling bulbs.

Your hands should be dry and free of oil
and grease.

If the newly installed bulb does not
come on, visit an authorized
Mercedes-Benz Light Truck Center.Have the LEDs and bulbs for the following
lamps replaced by an authorized
Mercedes-Benz Light Truck Center:

the additional turn signal lamps in the
exterior rear view mirrors

the high mounted brake lamp

the Bi-Xenon* low beam lamps

the Bi-Xenon high beam flasher spot-
light*
Warning!G
Bulbs and bulb sockets can be very hot.
Allow the lamp to cool down before chang-
ing a bulb.
Keep bulbs out of reach of children.
Halogen lamps contain pressurized gas.
A bulb can explode if you:

touch or move it when hot

drop the bulb

scratch the bulb
Wear eye and hand protection.
Because of high voltage in Xenon lamps, it is
dangerous to replace the bulb or repair the
lamp and its components. We recommend
that you have such work done by a qualified
technician.
!Do not replace the LEDs yourself. You could
otherwise damage the LEDs or parts of the vehi-
cle. Only have the LEDs replaced by a an autho-
rized Mercedes-Benz Light Truck Center.
iReplacing the bulbs for the front lamps is a
technically complex process. For your conve-
nience, we recommend that you have this work
carried out by an authorized Mercedes-Benz
Light Truck Center.
Have the headlamp adjustment checked
regularly.
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507 Practical hints
Replacing bulbs
Replacing bulbs for front lamps
Before you start to replace a bulb for a
front lamp, do the following first:
Turn the exterior lamp switch to
positionM (
page 143).
Open the hood (page 378).
1Housing cover for low beam halogen
headlamp
2Housing cover for high beam halogen
bulb (high beam and high beam flasher)
3Bulb socket for parking and standing
lamp bulb
4Bulb socket for turn signal lamp bulb
5Bulb socket for side marker lamp bulbLow beam bulb (halogen headlamp)
1Low beam headlamp cover
2Bulb socket for low beam headlamp
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508 Practical hints
Replacing bulbs
Turn cover1 counterclockwise.
Remove cover1.
Turn bulb socket2 counterclockwise.
Pull bulb socket2 out of the
headlamp housing.
Pull the low beam bulb out of bulb
socket2.
Insert the new low beam bulb into bulb
socket2.
Insert bulb socket2 into the
headlamp housing.
Turn bulb socket2 clockwise until it
engages.
Place cover1 on the opening in the
headlamp housing.
Turn cover1 clockwise until it engag-
es.Bi-Xenon* low beam/high beam
headlampHigh beam bulb (halogen headlamp)
1High beam headlamp cover
2Bulb socket for high beam headlamp
Warning!G
Do not remove the low beam/high beam
cover for the Bi-Xenon* headlamp. Because
of high voltage in Xenon* lamps, it is danger-
ous to replace the bulb or repair the lamp
and its components. We recommend that
you have such work done by a qualified
technician.
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509 Practical hints
Replacing bulbs
Turn cover1 counterclockwise.
Remove cover1.
Turn bulb socket2 counterclockwise.
Pull bulb socket2 out of the
headlamp housing.
Pull the high beam bulb out of bulb
socket2.
Insert the new high beam bulb into bulb
socket2.
Insert bulb socket2 into the
headlamp housing.
Turn bulb socket2 clockwise until it
engages.
Place cover1 on the opening in the
headlamp housing.
Turn cover1 clockwise until it engag-
es.Turn signal lamp bulb
1Bulb socket for turn signal lamp
Turn bulb socket1 counterclockwise.
Pull bulb socket1 out of the
headlamp housing.
Pull the turn signal bulb out of bulb
socket1.
Insert the new turn signal bulb into bulb
socket1.
Insert bulb socket1 into the
headlamp housing.
Turn bulb socket1 clockwise until it
engages.Parking and standing lamp bulb
Turn bulb socket3 (page 507)
counterclockwise.
Pull bulb socket3 out of the
headlamp housing.
Pull the bulb out of bulb socket3.
Insert the new bulb into bulb
socket3.
Insert bulb socket3 into the
headlamp housing.
Turn bulb socket3 clockwise until it
engages.
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