Page 341 of 561

340 Operation
At the gas station
Brake fluid
Coolant
For normal replenishing, use water (pota-
ble water quality).
For more information, see “Coolant level”
(
page 345) and see “Fuels, coolants, lu-
bricants” (
page 522).Windshield/rear window washer
system and headlamp cleaning
system*
For more information on refilling the wash-
er reservoir, see “Windshield/rear window
washer system and headlamp cleaning
system*” (
page 346).
Vehicle lighting
Check function and cleanliness. For infor-
mation on replacing light bulbs, see “Re-
placing bulbs” (
page 463).
For more information, see “Exterior lamp
switch” (
page 135).
Tire inflation pressure
For more information, see “Checking tire
inflation pressure” (
page 359).
!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 immediately. Notify an
authorized Mercedes-Benz Light Truck Center
immediately. Do not add brake fluid as this will
not solve the problem. For more information, see
“Brake fluid” (
page 525).
Page 401 of 561

400 Practical hints
What to do if …
Lamps in instrument clusterGeneral information:
If any of the following lamps in the instru-
ment cluster fails to come on during thebulb self-check when switching on the
ignition, have the respective bulb checked
and replaced if necessary.
ProblemPossible cause/consequenceSuggested solution
-The yellow ABS indicator lamp
comes on while the engine is
running.ABS has detected a malfunction and has
switched off. The BAS, ESP®, EBP, and 4-ETS
are also switched off (see messages in multi-
function display).
The brake system is still functioning normally
but without the ABS available.
If the ABS control unit is malfunctioning,
other systems such as the navigation
system* or the automatic transmission may
also be malfunctioning.
Continue driving with added caution.
Wheels may lock during hard braking,
reducing steering capability.
Read and observe messages in the
multifunction display (
page 413).
Have the system checked at an
authorized Mercedes-Benz Light
Truck Center as soon as possible.
Failure to follow these instructions
increases the risk of an accident.
The charging voltage has fallen below
10 volts. The ABS has switched off.
The battery might not be charged sufficiently.When the voltage is above this value
again, the ABS is operational again and
the ABS indicator lamp should go out.
If the ABS indicator lamp does not go out:
Have the generator (alternator) and
the battery checked.
Page 439 of 561

438 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
. 3rd Brake LampThe high mounted brake lamp is
malfunctioning. This message
will only appear if a critical num-
ber of LEDs have stopped work-
ing.Contact an authorized Mercedes-Benz
Light Truck Center as soon as possible.
Active Headlamps
InoperativeThe active Bi-Xenon* headlamp
system is malfunctioning.Contact an authorized Mercedes-Benz
Light Truck Center as soon as possible.
AUTO Light
InoperativeThe light sensor is malfunction-
ing. The headlamps switch on
automatically.Contact an authorized Mercedes-Benz
Light Truck Center as soon as possible.
To switch off the headlamps
(U. S. vehicles only):
In the control system, set lamp operation
to manual mode (
page 136).
Switch off the headlamps using the
exterior lamp switch (
page 135).
Brake Lamp
LeftThe left brake lamp is malfunc-
tioning. A substitute bulb is
being used.Replace the bulb as soon as possible
(
page 471).
Brake Lamp
RightThe right brake lamp is malfunc-
tioning. A substitute bulb is
being used.Replace the bulb as soon as possible
(
page 471).
Page 440 of 561

439 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 469).
Cornering Lamp
RightThe right corner-illuminating front fog
lamp is malfunctioning.Replace the bulb as soon as possible
(
page 469).
Front Foglamp
LeftThe left front fog lamp is malfunctioning.Replace the bulb as soon as possible
(
page 469).
Front Foglamp
RightThe right front fog lamp is malfunctioning.Replace the bulb as soon as possible
(
page 469).
High Beam
LeftThe left high beam lamp is
malfunctioning.Halogen headlamp:
Replace the bulb as soon as possible
(
page 467).
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 467).
Bi-Xenon* headlamp:
Contact an authorized Mercedes-Benz
Light Truck Center as soon as possible.
Page 441 of 561
440 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
. License Plate Lamp
LeftThe left license plate lamp is
malfunctioning.Replace the bulb as soon as possible
(
page 473).
License Plate Lamp
RightThe right license plate lamp is
malfunctioning.Replace the bulb as soon as possible
(
page 473).
Low Beam
LeftThe left low beam lamp is
malfunctioning.Halogen headlamp:
Replace the bulb as soon as possible
(
page 466).
Bi-Xenon* headlamp:
Contact an authorized Mercedes-Benz
Light Truck Center as soon as possible.
Low Beam
RightThe right low beam lamp is
malfunctioning.Halogen headlamp:
Replace the bulb as soon as possible
(
page 466).
Bi-Xenon* headlamp:
Contact an authorized Mercedes-Benz
Light Truck Center as soon as possible.
Page 443 of 561
442 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 135).
Tail Lamp
LeftThe left tail lamp is malfunction-
ing. A substitute bulb is being
used.Replace the bulb as soon as possible
(
page 471).
Tail Lamp
RightThe right tail lamp is malfunc-
tioning. A substitute bulb is be-
ing used.Replace the bulb as soon as possible
(
page 471).
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).