Page 418 of 522
417 Practical hints
What to do if …
Display symbol
Display message
Possible cause/consequence
Possible solution
•
The cooling fan for the coolant is malfunc-
tioning.
Observe the coolant temperature indicator
in the instrument cluster (
page 27).
If the coolant temperature is under 248°F
(120°C), you may continue driving to an au-
thorized Mercedes-Benz Center.
Avoid placing heavy loads on the engine
(e.g. by driving uphill) as well as
stop-and-go traffic.
Have the fan replaced as soon as possible.
±
Display malfunction
Visit workshop
Certain electronic systems are unable to
relay information to the control system.
The following systems may have failed:
Coolant temperature display
Tachometer
Cruise control display
Have the electronic systems checked by an
authorized Mercedes-Benz Center.
Engine
Service
There may be a malfunction in:
the fuel injection system
the ignition system
the exhaust system
Have the engine checked as soon as possi-
ble by an authorized Mercedes-Benz Cen-
ter.
Page 419 of 522
418 Practical hintsWhat to do if …When the message
Check oil level at
next refueling
appears while the engine
is running and at operating temperature,
the engine oil level has dropped to approx-
imately 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 ser-
vice station where the engine oil should be
topped to the required level with an ap-
proved engine oil.For information on approved engine oils,
refer to the Factory Approved Service
Products pamphlet (USA only) or contact
an authorized Mercedes-Benz Center.
Display symbol
Display message
Possible cause/consequence
Possible solution
:
Check oil level
at next refueling
The engine oil has dropped to a critical
level.
Check the engine oil level
(page 328) and add oil as required
(page 329).
If you must add engine oil frequently,
have the engine checked for possible
leaks.
!
The engine oil level warnings should not be
ignored. Extended driving with the symbol dis-
played could result in serious engine damage
that is not covered by the Mercedes-Benz
Limited Warranty.
Page 420 of 522
419 Practical hints
What to do if …
Display symbol
Display message
Possible cause/consequence
Possible solution
A
Reserve fuel
The fuel level has dropped below the re-
serve mark.
Refuel at the next gas station
(page 321).
Gas cap is open
A loss of pressure has been detected in
the fuel system. The fuel cap may not be
closed properly or the fuel system may be
leaky.
Check the fuel cap (
page 321).
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 Center.
»
Replace air cleaner
The air cleaner is clogged.
Have the air cleaner checked by an au-
thorized Mercedes-Benz Center.
[
Clean fuel filter
Diesel engine:
There is water in the fuel filter.
Have the water drained by an autho-
rized Mercedes-Benz Center as soon as
possible.
Page 421 of 522
420 Practical hintsWhat to do if …Display symbol
Display message
Possible cause/consequence
Possible solution
F
Key
still in vehicle
A SmartKey with KEYLESS-GO* left in the
vehicle was recognized while locking the
vehicle from the outside.
Take the SmartKey with
KEYLESS-GO* out of the vehicle.
Please don't
forget your key
This display appears (for a maximum of
60 seconds) if the driver’s door is opened
with the engine shut off and no SmartKey
in the starter switch.
This message is only a reminder.
Take the SmartKey or SmartKey with
KEYLESS-GO* with you when leaving
the vehicle.
Remove key
You have forgotten to remove the
SmartKey.
Remove the SmartKey from the
starter switch.
Get a new key
The SmartKey is malfunctioning.
Contact an authorized
Mercedes-Benz Center.
Page 422 of 522
421 Practical hints
What to do if …
Display symbol
Display message
Possible cause/consequence
Possible solution
F
Change
key batteries
The SmartKey with KEYLESS-GO* batter-
ies are discharged.
Replace the batteries (
page 441).
Key
not recognized
The SmartKey with KEYLESS-GO* is not
recognized while the engine is running
because
the SmartKey with KEYLESS-GO* is
not in the vehicle
there is strong radio-frequency inter-
ference
Stop the vehicle as soon as it is safe
to do so.
Search for the SmartKey with
KEYLESS-GO*.
Otherwise the vehicle cannot be cen-
trally locked nor can the engine be
started again after the engine is
stopped.
Key
not recognized
The SmartKey with KEYLESS-GO* is mo-
mentarily not recognized.
Change the position of the SmartKey
in the vehicle.
Operate the vehicle with the
SmartKey in the starter switch if nec-
essary.
Page 423 of 522
422 Practical hintsWhat to do if …Display symbol
Display message
Possible cause/consequence
Possible solution
.
Active headlamps
inoperative
The active Bi-Xenon* headlamp system is
malfunctioning.
Contact an authorized Mercedes-Benz
Center as soon as possible.
Active headlamps
Auxiliary bulb on
The active Bi-Xenon* headlamps are mal-
functioning. Another light is being used.
Contact an authorized Mercedes-Benz
Center as soon as possible.
Reverse lamp
left side
The left reverse lamp is malfunctioning.
Replace the bulb as soon as possible.
Reverse lamp
right side
The right reverse lamp is malfunctioning.
Replace the bulb as soon as possible.
Brake-/tail lamp, left
Auxiliary bulb on
The left brake/tail lamp is malfunction-
ing.
This message will only appear if a critical
number of LEDs have stopped working.
Contact an authorized Mercedes-Benz
Center as soon as possible.
Brake-/tail lamp, right
Auxiliary bulb on
The right brake/tail lamp is malfunction-
ing.
This message will only appear if a critical
number of LEDs have stopped working.
Contact an authorized Mercedes-Benz
Center as soon as possible.
3rd brake lamp
The high mounted brake lamp is malfunc-
tioning.
This message will only appear if a critical
number of LEDs have stopped working.
Contact an authorized Mercedes-Benz
Center as soon as possible.
Page 424 of 522
423 Practical hints
What to do if …
Display symbol
Display message
Possible cause/consequence
Possible solution
.
Front foglamp
left side
The left front fog lamp is malfunctioning.
Contact an authorized Mercedes-Benz
Center as soon as possible.
Front foglamp
right side
The right front fog lamp is malfunction-
ing.
Contact an authorized Mercedes-Benz
Center as soon as possible.
Front left
marker lamp
The front left side marker lamp is mal-
functioning.
Contact an authorized Mercedes-Benz
Center as soon as possible.
Front right
marker lamp
The front right side marker lamp is mal-
functioning.
Contact an authorized Mercedes-Benz
Center as soon as possible.
Front left park. lamp
Auxiliary bulb on
The left front parking lamp is malfunc-
tioning. A substitute bulb is being used.
Contact an authorized Mercedes-Benz
Center as soon as possible.
Front right park. lamp
Auxiliary bulb on
The right front parking lamp is malfunc-
tioning. A substitute bulb is being used.
Contact an authorized Mercedes-Benz
Center as soon as possible.
High beam
left side
The left high beam lamp is malfunction-
ing.
Replace the bulb as soon as possible.
High beam
right side
The right high beam lamp is malfunction-
ing.
Replace the bulb as soon as possible.
License plate lamp
left side
The left license plate lamp is malfunction-
ing.
Replace the bulb as soon as possible.
License plate lamp
right side
The right license plate lamp is malfunc-
tioning.
Replace the bulb as soon as possible.
Page 425 of 522
424 Practical hintsWhat to do if …Display symbol
Display message
Possible cause/consequence
Possible solution
.
AUTO-Light
inoperative
The light sensor is malfunctioning. The
headlamps switch on automatically.
In the control system, set lamp operation
to manual mode (
page 138).
Switch on headlamps using the exterior
lamp switch.
Low beam
left side
The left low beam lamp is malfunction-
ing.
Halogen headlamp:
Replace the bulb as soon as possible.
Bi-Xenon* headlamp:
Contact an authorized Mercedes-Benz
Center as soon as possible.
Low beam
right side
The right low beam lamp is malfunc-
tioning.
Halogen headlamp:
Replace the bulb as soon as possible.
Bi-Xenon* headlamp:
Contact an authorized Mercedes-Benz
Center as soon as possible.
