Page 444 of 561

443 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 471).
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 471).
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 468).
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 468).
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. 
     
        
        Page 464 of 561
463 Practical hints
Replacing bulbs
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 438). 
     
        
        Page 465 of 561
464 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
9Brake lampP21W
aBackup lampP21W
bTurn signal lampPY 21 W
cSide marker lampP 21/4 W
dTail, parking, standing 
lamp, rear fog lamp 
(driver’s side only)P 21/4 W
eLicense plate lampsC5W 
     
        
        Page 466 of 561

465 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. 
     
        
        Page 467 of 561
466 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 135).
Open the hood (page 341).
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 
     
        
        Page 469 of 561

468 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 466) 
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. 
     
        
        Page 471 of 561

470 Practical hints
Replacing bulbs
Turn the hook or screwdriver 90°.
Hold the cover1 and pull the hook or 
screwdriver outwards.
You can now access the front fog lamp.
Example illustration ML350 (Sport Package 
similar)
3Retaining screws
Turn retaining screws3 counterclock-
wise.
Remove front fog lamp2 out of the 
bumper.
Pull electrical connector off.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.
 
     
        
        Page 473 of 561
472 Practical hints
Replacing bulbs
Opening the passenger side trim panel:
1Lock
2Cover in right side trim panel
Insert a suitable object such as a coin 
into the slot of lock1.
Turn lock1 counterclockwise by 90° 
in direction of arrow.
Remove cover2.Replacing bulbs
Example illustration rear lamp passen-
ger-side
1Brake lamp
2Backup lamp
3Rear fog lamp (only driver’s side), tail 
lamp, parking and standing lamp
4Side marker lamp
5Turn signal lamp
Depending on which bulb needs to be 
replaced, turn the respective bulb 
socket1-5 counterclockwise.
Press gently onto the respective bulb 
and turn counterclockwise out of its 
bulb socket.
Press the new bulb gently into its bulb 
socket and turn clockwise until it en-
gages.
Align the respective bulb 
socket1-5 and turn it clockwise.
Make sure bulb socket is attached 
properly.
Close the respective cover in the cargo 
compartment.
Close the tailgate (page 119).