Page 480 of 595

479 Practical hints
What to do if …
Display symbolDisplay messagesPossible cause/consequencePossible solution
FKey
not detectedThe 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 interference
Stop the vehicle in a safe location or as
soon as it is safe to do so.
Apply the parking brake (page 68).
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 recognized.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 recognized
while the ignition is switched on
(
page 41) 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 481 of 595

480 Practical hints
What to do if …
Display symbolDisplay messagesPossible 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*.Visit 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 506).
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 the SmartKey in the starter switch
(
page 42).
or
Take the SmartKey with KEYLESS-GO*
with you when leaving the vehicle.
Page 486 of 595
485 Practical hints
What to do if …
Display symbolDisplay messagesPossible cause/consequencePossible solution
. Switch off lightsYou have removed the SmartKey
from the starter switch, opened
the driver’s door and left the
headlamps on or removed the
SmartKey with KEYLESS-GO*
from the vehicle and left the
headlamps on.Switch off the headlamps (page 69).
Switch off lights
or remove keyYou have opened the driver’s
door while the exterior lamp
switch is in positionU and
the SmartKey is still in the start-
er switch.
The parking lamps are still on.Switch off the headlamps (page 69).
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 515).
Tail lamp
RightThe right tail lamp is malfunc-
tioning. A substitute bulb is be-
ing used.Replace the bulb as soon as possible
(
page 515).
Page 501 of 595
500 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.
The mechanical key2 comes out.
Slide mechanical key2 out of the
housing.Unlocking the driver’s door
Insert mechanical key2 into the
driver’s door lock until it stops.
Turn mechanical key2 counterclock-
wise to position1 and hold it there.
Pull the door handle until the locking
knob moves up (
page 122).
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, insert the SmartKey or
SmartKey with KEYLESS-GO* in the starter
switch.
1Unlocking
2Mechanical key
Page 502 of 595

501 Practical hints
Unlocking/locking in an emergency
Locking the vehicle
If you cannot lock the vehicle with the
SmartKey or KEYLESS-GO*, lock the vehi-
cle 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 124).
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 504 of 595

503 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 70).
Open the driver’s door (this puts
the starter switch in position 0, same
as with the SmartKey removed from
the starter switch). The driver’s door
can then be closed again.
Press on cover1 at the position indi-
cated by the arrow.
Take off cover1.
2Crank
Take crank2 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
iThe hole may be covered by a noise
reduction padding. You will then have to push the
crank through the padding at the perforated
mark.
iTurn crank2 slowly and smoothly.
The tilt/sliding sunroof must be synchronized if
it has been operated manually (
page 255).
Page 507 of 595

506 Practical hints
Replacing SmartKey batteries
If the batteries in the SmartKey or the
SmartKey with KEYLESS-GO* are dis-
charged, 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 mechanical key1 from the
SmartKey or SmartKey with
KEYLESS-GO* (
page 500).1Mechanical key
2Battery compartment
Insert mechanical key1 into opening.
Press mechanical key1 in direction of
arrow.
The battery compartment2 is
unlatched.
Pull battery compartment2 out of the
SmartKey housing.
Warning!G
Keep the batteries out of reach of children.
If a battery is swallowed, seek medical help
immediately.
iWhen inserting the 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.
Page 508 of 595
507 Practical hints
Replacing SmartKey batteries
3Batteries
4Contact spring
Pull out batteries3.
Using a line-free cloth, insert new
batteries3 under contact springs4
with the positive terminal (+) side
facing up.
Return battery compartment2 into
housing until it locks into place.
Slide mechanical key1 back into the
SmartKey or SmartKey with
KEYLESS-GO*.
Check the operation of the SmartKey
or SmartKey with KEYLESS-GO*.