Page 461 of 570
460 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
c You are driving with one or more
doors open.Stop the vehicle in a safe location or as
soon as it is safe to do so.
Close the doors.
A Gas cap is openA 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 360).
If it is not closed properly:
Close the fuel cap.
If it is closed properly:
Have the fuel system checked by an
authorized Mercedes-Benz Light Truck
Center.
aYou are driving with the hood or
the tailgate open.Carefully bring the vehicle to a halt as
soon as it is safe to do so in a safe
location.
Close the hood (page 364) or the
tailgate (
page 125).
You are trying to lock the vehicle
with the KEYLESS-GO* function
with a door or the tailgate open.Close all doors and/or the tailgate
(
page 125).
Page 462 of 570

461 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
FKey
not detectedThe SmartKey with
KEYLESS-GO* is not detected
while the engine is running
because
the SmartKey with
KEYLESS-GO* is not in the
vehicle
there is strong
radio-frequency interference
Stop the vehicle as soon as it is safe to do
so.
Apply the parking brake (page 66).
Search for the SmartKey with
KEYLESS-GO*.
Otherwise the vehicle cannot be centrally
locked nor can the engine be started
again after the engine is stopped.
The SmartKey with
KEYLESS-GO* is momentarily
not detected.Change the position of the SmartKey with
KEYLESS-GO* in the vehicle.
Operate the vehicle with the SmartKey in
the starter switch if necessary.
Key
not detectedThe SmartKey with
KEYLESS-GO* is not detected
while the ignition is switched on
(
page 39) and a door is
opened or closed and the
SmartKey with KEYLESS-GO* is
not in the vehicle.
Search for the SmartKey with
KEYLESS-GO*.
Otherwise the vehicle cannot be locked
nor can the engine be started.
Change the position of the SmartKey with
KEYLESS-GO* in the vehicle.
Page 463 of 570

462 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
FKey detected
in vehicleA SmartKey with KEYLESS-GO*
left in the vehicle was detected
while trying to lock the vehicle
from the outside.Take the SmartKey with KEYLESS-GO*
out of the vehicle.
Remove keyYou have forgotten to remove
the SmartKey.Remove the SmartKey from the starter
switch.
You need a new keyThere is no additional code avail-
able for SmartKey or SmartKey
with KEYLESS-GO*.Contact an authorized Mercedes-Benz
Light Truck Center as soon as possible.
Change
key batteriesThe batteries in the SmartKey
with KEYLESS-GO* are dis-
charged.Replace the batteries (page 483).
Don’t forget
your keyThis message 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.
or
Take the SmartKey with KEYLESS-GO*
with you when leaving the vehicle.
Page 468 of 570
467 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 headlamps on.Turn the exterior lamp switch toM
(
page 146).
Switch off lights
or remove keyYou have opened the driver’s
door while the exterior lamp
switch is in position U and
the SmartKey is still in the
starter switch.
The parking lamps are still on.Turn the exterior lamp switch toM
(
page 146).
or
Remove the SmartKey from the starter
switch.
Tail lamp
LeftThe left tail lamp is malfunction-
ing. A substitute bulb is being
used.Replace the bulb as soon as possible
(
page 484).
Tail lamp
RightThe right tail lamp is malfunc-
tioning. A substitute bulb is
being used.Replace the bulb as soon as possible
(
page 484).
Page 479 of 570

478 Practical hints
Unlocking / locking in an emergency
Unlocking the vehicle
If you cannot unlock the vehicle with the
SmartKey or KEYLESS-GO*, open the
driver’s door using the mechanical key.Removing the mechanical key
1Mechanical key locking tab
2Mechanical key
Move locking tab1 in direction of
arrow.
Slide mechanical key2 out of the
housing.Unlocking the driver’s door
1Unlocking
2Mechanical key
Insert mechanical key 2 into the
driver’s door lock until it stops.
Turn mechanical key 2 counterclock-
wise to position1 and hold it there.
Pull the door handle until the locking
knob moves up.
The driver’s door is unlocked.
Pull the door handle once more to open
the driver’s door.
iUnlocking the driver’s door with the
mechanical key will trigger the anti-theft
alarm system.
To cancel the alarm:
Press buttonŒ or‹on the
SmartKey.
Insert the SmartKey in the starter switch.
Vehicles with KEYLESS-GO*:
Grasp an outside door handle.
The SmartKey with KEYLESS-GO must be
within 3 ft (1 m) of the vehicle.
Press the KEYLESS-GO start / stop button
(
page 41).
The SmartKey with KEYLESS-GO must be
inside the vehicle.
Page 480 of 570

479 Practical hints
Unlocking / locking in an emergency
Locking the vehicle
If you cannot lock the vehicle with the
SmartKey or KEYLESS-GO*, lock the
vehicle carrying out the following steps.
Close the front passenger door, the
rear right door and the tailgate.
Open the driver’s door and the rear left
door.
Press the central locking switch on the
driver’s door (
page 130).
The locking knobs of the front passen-
ger door and the rear doors move
down.
If the vehicle battery is disconnected or
drained:
Press down the locking knobs of
the front passenger door and the
rear doors manually.
Exit the vehicle.
Close the driver’s door.
Enter the vehicle through the rear left
door.
Press down the locking knob of the
driver’s door.
Exit the vehicle.
Close the rear left door.
The vehicle is locked.
Fuel filler flap
Open the tailgate (page 123).
The fuel filler flap release is located behind
a cover in the right side trim panel of the
cargo compartment.
1Lock
2Cover
!To prevent inadvertent lockout, make sure
to have the SmartKey or SmartKey with
KEYLESS-GO* with you before proceeding with
the next step. The next step will lock the vehicle.
iThis procedure does not arm the anti-theft
alarm system, nor does it lock the fuel filler flap.
Page 482 of 570

481 Practical hints
Opening / closing in an emergency
Opening / closing in an emergency
Power tilt/sliding sunroof*
You can open or close the tilt/sliding
sunroof manually should an electrical
malfunction occur.
The tilt/sliding sunroof drive is located
behind a cover on the overhead control
panel.
1Cover
Remove the SmartKey from the starter
switch.Vehicles with KEYLESS-GO*:
Turn off the engine by pressing the
KEYLESS-GO start/stop button
(
page 67).
Open the driver’s door (this puts
the starter switch to position0,
same as with the SmartKey
removed from starter switch).
The driver’s door can then be
closed again.
Press on cover1 at the position
indicated by the arrow.
Take off cover 1.
2Crank
Take crank 2 out of the Operator’s
Manual pouch.
Insert crank2 into hole.
Turn crank2 clockwise to
slide sunroof closed
raise sunroof at the rear
Turn crank2 counterclockwise to
slide sunroof open
lower sunroof at the rear
iTurn crank2 slowly and smoothly.
The tilt/sliding sunroof must be synchronized if
it has been operated manually (
page 260).
iThe panorama roof with power tilt/sliding
panel* cannot be operated as described.
Contact Roadside Assistance or an authorized
Mercedes-Benz Light Truck Center.
Page 484 of 570

483 Practical hints
Replacing SmartKey batteries
Replacing SmartKey batteries
If the batteries in the SmartKey or the
SmartKey with KEYLESS-GO* are
discharged, the vehicle can no longer be
locked or unlocked. It is recommended to
have the batteries replaced at an autho-
rized Mercedes-Benz Light Truck Center.
Batteries contain materials that can harm
the environment if disposed of improperly.
Recycling of batteries is the preferred
method of disposal. Many states require
sellers of batteries to accept old batteries
for recycling.Replacement batteries: Lithium, type
CR 2025 or equivalent.
Remove the mechanical key from the
SmartKey (
page 478).
1Mechanical key
2Battery compartment
Insert mechanical key 1 into opening.
Press mechanical key 1 in direction of
arrow.
The battery compartment is unlatched.
Pull battery compartment 2 out of the
SmartKey housing.
3Batteries
4Contact springs
Pull out batteries3.
Using a line-free cloth, insert new bat-
teries 3 under contact springs 4 with
the positive terminal (+) side facing up.
Return battery compartment 2 into
housing until it locks into place.
Slide mechanical key 1 back into
SmartKey.
Check the operation of the SmartKey
or SmartKey with KEYLESS-GO*.
Warning!G
Keep the batteries out of reach of children.
If a battery is swallowed, seek medical help
immediately.
iWhen replacing batteries, make sure they
are clean and free of lint.
iWhen replacing batteries, always replace
both batteries. The required replacement
batteries are available at any Mercedes-Benz
Light Truck Center.