Page 430 of 561
429 Practical hints
What to do if …
Symbol messagesDisplay symbol
Display messages
Possible cause/consequence
Possible solution
#
malfunction
Visit workshop
The battery is no longer charg-
ing.
Possible causes:
alternator malfunctioning
broken poly-V-belt
Do not forget that the brake sys-
tem requires electrical energy
and may be operating with re-
stricted capability. Considerably
greater brake pedal force is
required and the stopping dis-
tance is increased.
Stop in a safe location or as soon as it is
safe to do so and check the poly-V-belt.
If it is broken:
Do not continue to drive. Otherwise the
engine will overheat due to an inoperative
water pump which may result in damage
to the engine. Notify an authorized
Mercedes-Benz Light Truck Center.
If it is intact:
Drive immediately to the nearest autho-
rized Mercedes-Benz Light Truck Center.
Adjust driving to be consistent with
reduced braking responsiveness.
Page 431 of 561
430 Practical hintsWhat to do if …Display symbol
Display message
Possible cause/consequence
Possible solution
#
Undervoltage
Switch off consumers
The battery has insufficient
voltage.
Turn off unnecessary electrical
consumers.
Battery/Alternator
Stop vehicle
The battery is defective.
Stop the vehicle in a safe location or as
soon as it is safe to do so.
Do not continue to drive.
Notify an authorized Mercedes-Benz
Light Truck Center.
2
Brake wear
Visit workshop
The brake pads have reached
their wear limit.
Have the brake pads replaced as soon as
possible.
!Brake pad thickness must be visually
inspected by a qualified technician at
the intervals specified in the
Maintenance Booklet.
Page 432 of 561
431 Practical hints
What to do if …
Display symbol
Display message
Possible cause/consequence
Possible solution
;
(USA only)
!
(Canada only)
Release
parking brake
You are driving with the parking
brake set.
Release the parking brake (
page 56).
;
(USA only)
3
(Canada only)
Changed braking behavior
Drive with extreme care
A malfunction in the Electronic
Brake Proportioning
(page 102) was detected.
Continue driving with added caution.
Wheels may lock during hard braking,
reducing steering capability.
Read and observe messages in the multi-
function display.
Have the system checked at an autho-
rized Mercedes-Benz Light Truck Center
as soon as possible.
Failure to follow these instructions increases
the risk of an accident.
Page 433 of 561
432 Practical hintsWhat to do if …Display symbol
Display message
Possible cause/consequence
Possible solution
;
(USA only)
3
(Canada only)
Brake fluid too low
Visit workshop
There is insufficient brake fluid
in the reservoir.
Risk of accident! Stop the vehicle in a
safe location or as soon as it is safe to do
so and notify an authorized
Mercedes-Benz Light Truck Center. Do
not add brake fluid! This will not solve the
problem.
Warning!
G
Driving with the message
Brake fluid
too low Visit workshop
displayed can
result in an accident. Have your brake
system checked immediately. Do not add
brake fluid before checking the brake
system. Overfilling the brake fluid reservoir
can result in spilling brake fluid on hot
engine parts and the brake fluid catching
fire. You can be seriously burned.
!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.
Page 443 of 561

442 Practical hintsWhat to do if …Display symbol
Display messages
Possible cause/consequence
Possible solution
.
3rd brake lamp
The high mounted brake lamp is
malfunctioning. This message
will only appear if all light
emitting diodes have stopped
working.
Visit an authorized Mercedes-Benz Light
Truck Center as soon as possible.
Brake lamp, left
Substitute bulb on
The left brake lamp is malfunc-
tioning. A substitute bulb is
being used.
Replace the bulb as soon as possible.
Brake lamp, right
Substitute bulb on
The right brake lamp is malfunc-
tioning. A substitute bulb is
being used.
Replace the bulb as soon as possible.
Brake lamp
Drive to workshop
Brake lamp illumination is de-
layed or lamp is permanently on.
Visit an authorized Mercedes-Benz Light
Truck Center as soon as possible.
Display malfunction
Visit workshop
The display for the lamps or the
system is malfunctioning.
Visit an authorized Mercedes-Benz Light
Truck Center as soon as possible.
Front foglamp,
left
The left front fog lamp is
malfunctioning.
Replace the bulb as soon as possible.
Front foglamp,
right
The right front fog lamp is
malfunctioning.
Replace the bulb as soon as possible.
Rear fog lamp
The rear fog lamp is malfunction-
ing.
Replace the bulb as soon as possible.
Page 466 of 561
465 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 humidity, driving the vehicle a dis-
tance with the lights on should clear up
the fogging.
iBackup bulbs will be brought into use
when the following lamps malfunction:
Turn signal lamps
Brake lamps
Parking lamps
Tail lamps
Read and observe messages in the
multifunction display (
page 442).
Page 467 of 561
466 Practical hintsReplacing bulbsFront lamps Rear lamps
Lamp
Type
1
Parking/standing lamp
W 5 W
2
Turn signal lamp
PY 21 W
3
Additional turn signal
lamp
LED
4
Headlamps:
Low beam
H7 (55W)
Bi-Xenon headlamps*:
Low beam
1
1Vehicles with Bi-Xenon* headlamps: Do not
replace the Bi-Xenon bulbs yourself. Contact an
authorized Mercedes-Benz Light Truck Center.
D2S-35 W
5
Headlamps:
High beam/high beam
flasher
H7 (55W)
Bi-Xenon headlamps*:
High beam/high beam
flasher spot lamp
H7 (55W)
6
Sidemarker lamp
WY 5 W
7
Corner-illuminating
front fog lamp*
H11 (55W)
Lamp
Type
8
High-mounted brake
lamp
LED
9
Tail, brake, and
sidemarker lamp
P 21 W
a
Turn signal lamp
PY 21 W
b
Backup lamp
P 21 W
c
Rear fog lamp (driver’s
side only)
P 21 W
d
License plate lamps
C 5 W
Page 468 of 561

467 Practical hints
Replacing bulbs
Notes on bulb replacement
Only use 12-volt bulbs of the same type
and with the specified watt rating.
Switch the 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*
the front sidemarker lamps
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.