2008 MERCEDES-BENZ GL550 bulb

481 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
. Switch Off LightsYou have removed the SmartKey
from the starter switch and
opened the driver’s door or
removed the SmartKey with
KEYLESS-GO* from the vehicle
and left the parking lamps or the
rear fog lamp on.Turn the exterior lamp switch toM
(
page 143).
Tail Lamp
LeftThe left tail lamp is malfunction-
ing. A substitute bulb is being
used.Replace the bulb as soon as possible
(
page 511).
Tail Lamp
RightThe right tail lamp is malfunc-
tioning. A substitute bulb is be-
ing used.Replace the bulb as soon as possible
(
page 511).
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482 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
. Turn Signal
Rear LeftThe left rear turn signal lamp is
malfunctioning. A substitute
bulb is being used.Replace the bulb as soon as possible
(
page 511).
Turn Signal
Rear RightThe right rear turn signal lamp is
malfunctioning. A substitute
bulb is being used.Replace the bulb as soon as possible
(
page 511).
Turn Signal
Front LeftThe left front turn signal lamp is
malfunctioning. A substitute
bulb is being used.Replace the bulb as soon as possible
(
page 509).
Turn Signal
Front RightThe right front turn signal lamp is
malfunctioning. A substitute
bulb is being used.Replace the bulb as soon as possible
(
page 509).
Turn Signal
Left MirrorThe turn signal in the left exteri-
or rear view mirror is malfunc-
tioning. This message will only
appear if a critical number of
LEDs have stopped working.Contact an authorized Mercedes-Benz
Light Truck Center as soon as possible.
Turn Signal
Right MirrorThe turn signal in the right exte-
rior rear view mirror is malfunc-
tioning. This message will only
appear if a critical number of
LEDs have stopped working.Contact an authorized Mercedes-Benz
Light Truck Center as soon as possible.
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504 Practical hints
Replacing bulbs
Bulbs
Safe vehicle operation depends on proper
exterior lighting and signaling. It is there-
fore essential that all bulbs and lamp as-
semblies are in good working order at all
times.
Correct headlamp adjustment is extremely
important. Have headlamps checked and
readjusted at regular intervals and when a
bulb has been replaced. See an authorized
Mercedes-Benz Light Truck Center for
headlamp adjustment.iIf the headlamps or front fog lamps are
fogged up on the inside as a result of high humid-
ity, driving the vehicle a distance with the lights
on should clear up the fogging.iSubstitute bulbs will be brought into use
when the following lamps malfunction:

Turn signal lamps

Brake lamps

Parking lamps

Tail lamps
Read and observe the messages in the multi-
function display (
page 477).
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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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