Page 381 of 506

379 Practical hints
What to do if …
Display symbol
Display messages
Possible cause
Possible solution
#
Battery/Alternator
Stop vehicle
The battery is malfunctioning.
The SBC brake system requires electrical
energy and therefore has only limited op-
eration. Considerably greater brake pedal
force is required and the stopping dis-
tance is increased.
Stop the vehicle as soon as it is safe
to do so. Adjust driving to be consis-
tent with reduced braking responsive-
ness.
Notify an authorized Mercedes-Benz
Center.
Low voltage
Start engine
The battery has insufficient voltage.
Start the engine (
page 46).
Malfunction
Electrical consumers
switched off
The consumer battery has insufficient
voltage and can no longer supply the con-
venience functions such as seat ventila-
tion*.
The electrical consumers will come back
online as soon as on-board voltage is suf-
ficient.
(
Backrest, right rear
not locked
The rear seat backrest is not engaged.
Adjust the rear seat backrest until it is
fully engaged in position.
Backrest, left rear
not locked
The rear seat backrest is not engaged.
Adjust the rear seat backrest until it is
fully engaged in position.
Page 392 of 506
390 Practical hintsWhat to do if …Display symbol
Display messages
Possible cause
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 out of the vehicle.
Keyless Go
Check system
The KEYLESS-GO* system is malfunction-
ing.
Visit an authorized Mercedes-Benz
Center as soon as possible.
Do not
forget 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.
Insert SmartKey in the starter switch.
Take the SmartKey with
KEYLESS-GO* with you when leaving
the vehicle.
Remove key
You have forgotten to remove the
SmartKey.
Remove the SmartKey from the start-
er switch.
Replace key
There is no additional code available for
SmartKey or SmartKey with
KEYLESS-GO*.
Visit an authorized Mercedes-Benz
Center as soon as possible.
Page 393 of 506
391 Practical hints
What to do if …
Display symbol
Display messages
Possible cause
Possible solution
F
Key
Check battery
The SmartKey with KEYLESS-GO* batter-
ies are discharged.
Change the batteries (
page 415).
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.
Otherwise the vehicle cannot be cen-
trally locked nor can the engine be
started again after the engine is
stopped.
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 395 of 506

393 Practical hints
What to do if …
Display symbol
Display messages
Possible cause
Possible solution
.
Low beam,
right
The right low beam lamp is malfunction-
ing.
Halogen headlamp:
Replace the bulb as soon as possible.
Bi-Xenon* headlamp:
Visit an authorized Mercedes-Benz
Center as soon as possible.
Front Marker light
,
left
The front left side marker lamp is mal-
functioning.
Replace the bulb as soon as possible.
Front Marker light
right
The front right side marker lamp is mal-
functioning.
Replace the bulb as soon as possible.
Fr. Park. lamp, left
The left parking lamps are malfunction-
ing.
Visit an authorized Mercedes-Benz
Center as soon as possible.
Fr. Park. lamp, right
The right parking lamps are malfunction-
ing.
Visit an authorized Mercedes-Benz
Center as soon as possible.
Rear foglamp
Substitute bulb on
The rear fog lamp is malfunctioning. A
substitute bulb is being used.
Replace the bulb as soon as possible.
Backup lamp, left
The left reverse lamp is malfunctioning.
Replace the bulb as soon as possible.
Backup lamp, right
The right reverse lamp is malfunctioning.
Replace the bulb as soon as possible.
Switch off lamps
Lamps have been turned on although the
SmartKey in the starter switch is in posi-
tion 0.
Switch off the headlights.
Page 396 of 506
394 Practical hintsWhat to do if …Display symbol
Display messages
Possible cause
Possible solution
.
High beam,
left
The left high beam lamp is malfunction-
ing.
Replace the bulb as soon as possible.
High beam,
right
The right high beam lamp is malfunction-
ing.
Replace the bulb as soon as possible.
License plate lamp,
left
The left license plate lamp is malfunction-
ing.
Replace the bulb as soon as possible.
License plate lamp,
right
The right license plate lamp is malfunc-
tioning.
Replace the bulb as soon as possible.
Light sensor
Drive to workshop
The lamp sensor is malfunctioning. The
headlamps switch on automatically.
In the control system, set lamp opera-
tion to manual mode (
page 162).
Switch on headlamps using the exteri-
or lamp switch.
Low beam,
left
The left low beam lamp is malfunctioning.
Halogen headlamp:
Replace the bulb as soon as possible.
Bi-Xenon* headlamp:
Visit an authorized Mercedes-Benz
Center as soon as possible.
Page 405 of 506
403 Practical hints
What to do if …
Display symbol
Display messages
Possible cause
Possible solution
<
Seat belt system
Drive to workshop
The seat belt system is malfunctioning.
Visit an authorized Mercedes-Benz
Center as soon as possible.
9
Service memory full
See Operator’s Manual
The maintenance service system memory
cannot save any more data.
Have the service memory checked by
an authorized Mercedes-Benz Center.
K
Close
Sunroof
You have opened the driver’s door with
the SmartKey removed from the starter
switch and the tilt/sliding sunroof open.
Close the tilt/sliding sunroof
(page 224).
J
Close
Sunroof
You have opened the driver’s door with
the SmartKey removed from the starter
switch and the tilt/sliding sunroof open.
Close the tilt/sliding sunroof
(page 224).
Page 412 of 506
410 Practical hintsUnlocking/locking in an emergencyUnlocking the vehicle
If you are unable to unlock the vehicle with
the SmartKey, open the driver’s door and
the trunk using the mechanical key.
1Mechanical key locking tab
2Mechanical key
Move locking tab1 in the direction of
the arrow and slide mechanical key2
out of the housing.Unlocking the driver’s door
3Unlocking
4Locking
Unlock the door with the mechanical
key. To do so, push the mechanical key
in the lock until it stops and turn it to
the left.
iUnlocking your vehicle with the me-
chanical key will trigger the anti-theft
alarm system. To cancel the alarm, do
one of the following:
Press button Œ or ‹ on the
SmartKey.
Insert the SmartKey in the starter
switch.
Press the KEYLESS-GO* start/stop
button (
page 35).
Page 413 of 506

411 Practical hints
Unlocking/locking in an emergency
Unlocking the trunk
A minimum height clearance of 5.90 ft
(1.80 m) is required to open the trunk lid.
If you are unable to unlock the trunk with
the SmartKey or KEYLESS-GO*, open the
trunk with the mechanical key.
The handle is located above the rear li-
cense plate recess.
1Unlocking in an emergency
2Handle
Insert the mechanical key into the
trunk lid lock.
Turn the mechanical key counterclock-
wise to position1 and hold it in this
position.
Pull trunk lid handle2 and lift the
trunk lid.
Locking the vehicle
If you are unable to lock the vehicle with
the SmartKey, lock it with the mechanical
key as follows:
Close the passenger doors and the
trunk.
Press the central locking switch in the
cockpit (
page 119).
Check to see whether the locking
knobs on the passenger doors are still
visible. If necessary, push them down
manually.
Slide mechanical key2 out of the
SmartKey.
Lock the driver’s door with the me-
chanical key (
page 411).
Check if the trunk is locked.
!Always make sure there is sufficient
overhead clearance.iUnlocking your vehicle with the me-
chanical key will trigger the anti-theft
alarm system. To cancel the alarm, do
one of the following:
Press buttonŒ or‹ on the
SmartKey.
Insert the SmartKey in the starter
switch.
Vehicles with KEYLESS-GO*:
Grasp the outside door handle.
Press the start/stop button.