Page 416 of 539

415 Practical hints
What to do if …
When the
Add 1 qt. engine oil when
next refueling
(Canada:
1 liter
) mes-
sage appears while the engine is running
and at operating temperature, the engine
oil level has dropped to approximately the
minimum level.
When this occurs, the warning will first
come on intermittently and then stay on if
the oil level drops further.Visually check for oil leaks. If no obvious oil
leaks are noted, drive to the nearest
service station where the engine oil should
be topped to the required level with an ap-
proved oil specified in the Factory
Approved Service Products pamphlet.
Display symbol
Display messages
Possible cause
Possible solution
N
Engine oil level
Visit workshop
The engine oil has dropped to a
critical level.
Check the engine oil level (
page 328)
(ML 500 only), or (
page 330) (ML 350
only) and add oil as required
(
page 331).
If you must add engine oil frequently, have
the engine checked for possible leaks.
Oil sensor malfunction
Visit workshop
The measuring system is mal-
functioning.
Have the measuring system checked by
an authorized Mercedes-Benz Light Truck
Center.
!The engine oil level warnings should
not be ignored. Extended driving with
the symbol displayed could result in
serious engine damage that is not
covered by the Mercedes-Benz Limited
Warranty.
Page 417 of 539

416 Practical hintsWhat to do if …Display symbol
Display messages
Possible cause
Possible solution
A
Reserve fuel
The fuel level has dropped below
the reserve mark.
Refuel at the next gas station
(page 323).
Check gas cap
See Operator’s Manual
A loss of pressure has been de-
tected in the fuel system. The
fuel cap may not be closed prop-
erly or the fuel system may be
leaky.
Check the fuel cap (
page 323).
If it is not closed properly:
Close the fuel cap.
If it is closed properly:
Have the fuel system checked by an au-
thorized Mercedes-Benz Light Truck Cen-
ter.
a
Hood open
Trunk open
You are driving with the hood or
the tailgate open.
Close the hood (
page 326) or the tail-
gate (
page 120).
F
Key
Check battery
The SmartKey with
KEYLESS-GO* batteries are
discharged.
Change the batteries (
page 440).
Please do
not forget key
This display appears (for a maxi-
mum of 60 seconds) if the driv-
er’s door is opened with the
engine shut off and no SmartKey
in the starter switch.
This message is only a reminder.
Insert SmartKey in the starter switch.
Take the SmartKey with KEYLESS-GO*
with you when leaving the vehicle.
Page 418 of 539
417 Practical hints
What to do if …
Display symbol
Display messages
Possible cause
Possible solution
F
Key
not detected
The SmartKey with
KEYLESS-GO* is not recognized
while the engine is running be-
cause
the SmartKey with
KEYLESS-GO* is not in the
vehicle
there is strong radio-fre-
quency interference
Stop the vehicle as soon as it is safe to do
so.
Search for the SmartKey.
Otherwise the vehicle cannot be centrally
locked nor can the engine be started
again after the engine is stopped.
Key
not detected
The SmartKey with
KEYLESS-GO* is momentarily
not recognized.
Change the position of the SmartKey in
the vehicle.
Operate the vehicle with the SmartKey in
the starter switch if necessary.
Remove key
You have forgotten to remove
the SmartKey.
Remove the SmartKey from the starter
switch.
Replace key
Drive to workshop
There is no additional code avail-
able for SmartKey or SmartKey
with KEYLESS-GO*.
Visit an authorized Mercedes-Benz Light
Truck Center as soon as possible.
Page 419 of 539

418 Practical hintsWhat to do if …Display symbol
Display messages
Possible cause
Possible solution
.
3rd brake lamp
The high mounted brake lamp is
malfunctioning. This message
will only appear if all light emit-
ting diodes have stopped work-
ing.
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 be-
ing used.
Visit an authorized Mercedes-Benz Light
Truck Center as soon as possible.
Brake lamp, right
Substitute bulb on
The right brake lamp is malfunc-
tioning. A substitute bulb is be-
ing used.
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 mal-
functioning.
Replace the bulb as soon as possible.
Front foglamp,
right
The right front fog lamp is mal-
functioning.
Replace the bulb as soon as possible.
Rear foglamp,
left
The left rear fog lamp is malfunc-
tioning.
Replace the bulb as soon as possible.
Rear foglamp,
right
The right rear fog lamp is mal-
functioning.
Replace the bulb as soon as possible.
Page 420 of 539

419 Practical hints
What to do if …
Display symbol
Display messages
Possible cause
Possible solution
.
Active headlamp
currently unavailable
The active Bi-Xenon* headlamps
system is malfunctioning.
Visit an authorized Mercedes-Benz Light
Truck Center as soon as possible.
Active headlamps
Substitute bulb on
The active Bi-Xenon* headlamps
system is malfunctioning. An-
other light is being used.
Visit an authorized Mercedes-Benz Light
Truck Center as soon as possible.
Active headlamps
inoperative
The active Bi-Xenon* headlamps
system is malfunctioning.
Visit an authorized Mercedes-Benz Light
Truck Center as soon as possible.
Active headlamp
s
Display malfunction
The active Bi-Xenon* headlamp
system is malfunctioning.
Visit an authorized Mercedes-Benz Light
Truck Center as soon as possible.
High beam,
left
The left high beam lamp is mal-
functioning.
Replace the bulb as soon as possible.
High beam,
right
The right high beam lamp is mal-
functioning.
Replace the bulb as soon as possible.
License plate lamp,
left
The left license plate lamp is
malfunctioning.
Replace the bulb as soon as possible.
License plate lamp,
right
The right license plate lamp is
malfunctioning.
Replace the bulb as soon as possible.
Page 421 of 539

420 Practical hintsWhat to do if …Display symbol
Display messages
Possible cause
Possible solution
.
Light sensor
Drive to workshop
The lamp sensor is malfunction-
ing. The headlamps switch on
automatically.
In the control system, set lamp operation
to manual mode.
Switch on headlamps using the exterior
lamp switch.
Low beam,
left
The left low beam lamp is mal-
functioning.
Visit an authorized Mercedes-Benz Light
Truck Center as soon as possible.
Low beam,
right
The right low beam lamp is mal-
functioning.
Visit an authorized Mercedes-Benz Light
Truck Center as soon as possible.
Marker lamp
,
front left
The front left side marker lamp is
malfunctioning.
Replace the bulb as soon as possible.
Marker lamp
,
front right
The front right side marker lamp
is malfunctioning.
Replace the bulb as soon as possible.
Parking lamp, front left
Substitute bulb on
The left parking lamps are mal-
functioning. A substitute bulb is
being used.
Visit an authorized Mercedes-Benz Light
Truck Center as soon as possible.
Parking lamp, front right
Substitute bulb on
The right parking lamps are mal-
functioning. A substitute bulb is
being used.
Visit an authorized Mercedes-Benz Light
Truck Center as soon as possible.
Page 422 of 539
421 Practical hints
What to do if …
Display symbol
Display messages
Possible cause
Possible solution
.
Reverse lamp,
left
The left reverse light is malfunc-
tioning.
Replace the bulb as soon as possible.
Reverse lamp,
right
The right reverse light is mal-
functioning.
Replace the bulb as soon as possible.
Switch off lights
Lamps have been turned on al-
though the SmartKey in the
starter switch is in position0.
Switch off the headlights.
Tail lamp, left
Substitute bulb on
The left tail lamp is malfunction-
ing. A substitute bulb is being
used.
Visit an authorized Mercedes-Benz Light
Truck Center as soon as possible.
Tail lamp, right
Substitute bulb on
The right tail lamp is malfunc-
tioning. A substitute bulb is be-
ing used.
Visit an authorized Mercedes-Benz Light
Truck Center as soon as possible.
Page 423 of 539

422 Practical hintsWhat to do if …Display symbol
Display messages
Possible cause
Possible solution
.
Turn signal, rear left
Substitute bulb on
The left rear turn signal lamp is
malfunctioning. A substitute
bulb is being used.
Replace the bulb as soon as possible.
Turn signal, rear right
Substitute bulb on
The right rear turn signal lamp is
malfunctioning. A substitute
bulb is being used.
Replace the bulb as soon as possible.
Turn signal, front left
Substitute bulb on
The left front turn signal lamp is
malfunctioning. A substitute
bulb is being used.
Replace the bulb as soon as possible.
Turn signal, front right
Substitute bulb on
The right front turn signal lamp is
malfunctioning. A substitute
bulb is being used.
Replace the bulb as soon as possible.
Turn signal in
mirror, left
The left turn signal in the side
mirror is malfunctioning. This
message will only appear if all
light emitting diodes have
stopped working.
Have the LEDs replaced as soon as possi-
ble.
Turn signal in
mirror, right
The right turn signal in the side
mirror is malfunctioning. This
message will only appear if all
light emitting diodes have
stopped working.
Have the LEDs replaced as soon as possi-
ble.