Page 436 of 595
435 Practical hints
What to do if …
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Unlocking/locking in an emergency
Opening/closing in an emergency
Resetting activated head restraints
Replacing SmartKey batteries
Replacing bulbs
Replacing wiper blades
Flat tire
Bleeding the fuel system
(diesel engine only)
Battery
Jump starting
Towing the vehicle
Fuses
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 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*.
Page 533 of 595

532 Practical hints
Battery
Disconnecting, removing, reinstalling
and reconnecting the battery
Step 1 (Disconnecting)
Set the automatic transmission to
positionP (
page 194).
Firmly depress the parking brake
(
page 68).
Turn off the engine (page 69).
Leave the ignition switched on
(
page 42).
!Never loosen or detach battery terminal
clamps while the engine is running or the
SmartKey is in the starter switch. Otherwise the
alternator and other electronic components
could be severely damaged.
Have the battery checked regularly by an
authorized Mercedes-Benz Light Truck Center.
Contact your authorized Mercedes-Benz Light
Truck Center for further information.
Warning!G
Do not place metal objects on the battery as
this could result in a short circuit.
Use leak-proof battery only to avoid the risk
of acid burns in the event of an accident.
Warning!G
Disconnecting, removing, reinstalling and
reconnecting the battery is a complicated
and technically demanding procedure that
a l s o r e q u i r e s s a f e t y p r e c a u t i o n s t o a v o i d t h e
risk of injury. We strongly recommend that it
be performed by a qualified technician or an
authorized Mercedes-Benz Light Truck
Center only. Please read the instructions
fully before beginning operation and only
undertake it if you feel fully capable of
performing all of the tasks involved as de-
scribed in these instructions. Observe all
safety instructions and precautions when
handling automotive batteries
(
page 530). Performing the tasks involved
incorrectly can cause damage to the vehicle
and impair the operating safety of the
vehicle, and/or cause severe injury to you
or others.
iWith a disconnected battery you will no
longer be able to turn the SmartKey in the starter
switch and pressing the KEYLESS-GO*
start/stop button will have no effect.
iIf your battery is discharged, the vehicle
must be jump started (
page 538) using the
jump start contacts in the engine compartment,
or an accessory battery charge unit* approved
by Mercedes-Benz must be connected using the
jump start contacts in the engine compartment
(see separate instructions for the accessory bat-
tery charge unit*) before any of the following
steps can be performed. If the battery cannot be
jumped or charged, please contact an
authorized Mercedes-Benz Light Truck Center.
Page 535 of 595
534 Practical hints
Battery
2Perforated floor carpet, unfolded
Fold the floor carpet piece2 in
direction of the arrow.
Move the front passenger seat to the
most forward and upward position
again (
page 46).
Switch off the ignition (page 42).
Remove SmartKey from starter switch.
Vehicles with KEYLESS-GO*:
Make sure the vehicle’s on-board
electronics have status0 (Turn off
the engine or all electrical systems
using the KEYLESS-GO start/stop
button. Open the driver’s door. With
the driver’s door open, the vehicle’s
on-board electronics have status0,
same as with the SmartKey
removed from the starter switch).
Enter the rear passenger compartment
again.Step 4 (Disconnecting)
3Air channel
4Clip with pin insert
Pull pin out of clip4 in direction of
arrow.
Pull clip with pin4 outwards.
Remove air channel3 by pulling it out
in direction of arrow.
iIf the vehicle battery is discharged and you
had the vehicle jump started, turn off the engine.
Page 537 of 595

536 Practical hints
Battery
Step 8 (Removing)
cBattery
Tilt the batteryc with the negative
terminal side upwards.
Take out the battery maintaining its
tilted position in the direction of the
arrow.Step 9 (Reinstalling)
Carry out step 8 in reverse order
(
page 536).
Battery, shown removed for illustration
9Battery ventilation hose
dVent plug
Carry out step 10 to reconnect the
battery (
page 536).
Follow steps 5 to 1 in reverse order to
completely reinstall the battery
(
page 535) to (page 532).
Step 10 (Reconnecting)
If the battery has been removed, first
carry out step 8 in reverse order
(
page 536).
Open the driver’s door.
Make sure all electrical consumers are
turned off.
Make sure the SmartKey is removed
from the starter switch.
Vehicles with KEYLESS-GO*:
Make sure the vehicle’s on-board
electronics have status0 (Open the
driver’s door. With the driver’s door
open, the vehicle’s on-board elec-
tronics have status0, same as with
the SmartKey removed from the
starter switch (
page 41)).
!The battery, the battery ventilation hose9
and the lateral plugd (
page 536) must
always be securely installed when the vehicle is
in operation.
Page 542 of 595

541 Practical hints
Towing the vehicle
Warning!G
With the engine not running, there is no
power assistance for the brake and steering
systems. In this case, it is important to keep
in mind that a considerably higher degree of
effort is necessary to brake and steer the
vehicle. Adapt your driving accordingly.
!When towing the vehicle with all wheels on
the ground:
The automatic transmission must be in
positionN (
page 193).
The starter switch must be in position2
(
page 41).
Keep in mind that it is important that the
starter switch is in position2. As soon as the
SmartKey is removed from the starter
switch or the engine is turned off with
KEYLESS-GO* and you open the driver’s
door or the front passenger door, the auto-
matic transmission will shift to park
positionP, see “Starter switch positions”
(
page 41).
The battery must be connected and charged.
Otherwise, the starter switch cannot be set
to position2 and the automatic transmission
will remain locked in positionP.
!Towing of the vehicle should only be done
using the properly installed towing eye bolt.
Never attach a tow cable, tow rope or tow rod to
the vehicle chassis, frame or suspension parts.
iWhen towing the vehicle with all wheels on
the ground, note the following:
With the automatic central locking activated and
the starter switch in position2 (
page 41), the
vehicle doors lock if a wheel is turning at a speed
of approximately 9 mph (15 km/h) or above.
To prevent the vehicle doors from locking,
deactivate the automatic central locking
(
page 130).
iTo signal turns while being towed with
hazard warning flasher in use, set the starter
switch to position2 and activate combination
switch for left or right turn signal in usual manner
– only the selected turn signal will operate.
Upon canceling the turn signal, the hazard
warning flasher will operate again.