2008 MERCEDES-BENZ GL550 Owner's Manual

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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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.
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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.
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