Page 461 of 561

460 Practical hintsUnlocking / locking in an emergencyUnlocking 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.
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 131).
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.!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.
Page 464 of 561

463 Practical hints
Replacing SmartKey batteries
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.
SmartKey
Replacement batteries: Lithium, type
CR 2025 or equivalent.
Remove mechanical key1 from the
SmartKey (
page 459).
1Mechanical key
2Slide
3Battery compartment
Insert mechanical key 1 in side open-
ing in direction of arrow.
Using mechanical key 1, push gray
slide 2 to unlatch battery compart-
ment 3.
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 re-
placement batteries are available at
any Mercedes-Benz Light Truck Center.
Page 465 of 561

464 Practical hintsReplacing SmartKey batteries
Pull battery compartment3out of the
housing in direction of arrow.
Remove the batteries in direction of ar-
row.
4Battery
5Contact spring
Using a lint-free cloth, insert new bat-
teries 4 under contact spring 5 with
the positive terminal (+) facing up.
Return battery compartment 3 into
housing until it locks into place.
Slide mechanical key 1 back into
SmartKey.
Check the operation of the SmartKey.
SmartKey with KEYLESS-GO*
Replacement batteries: Lithium, type
CR 2025 or equivalent.
Remove mechanical key1 from the
SmartKey with KEYLESS-GO
(page 459).
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 spring
Pull out batteries4.
Using a line-free cloth, insert new bat-
teries 4 under contact springs 3 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.
Page 488 of 561

487 Practical hints
Battery
Battery
The battery is located under the front
passenger seat.
The battery should always be sufficiently
charged in order to achieve its rated ser-
vice life.
If you use your vehicle mostly for
short-distance trips, you will need to have
the battery charge checked more
frequently.
When replacing the battery, always use
batteries approved by Mercedes-Benz.
If you do not intend to operate your vehicle
for an extended period of time, consult an
authorized Mercedes-Benz Light Truck
Center about steps you need to observe.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.
iMercedes-Benz recommends to have
the battery replaced at authorized
Mercedes-Benz Light Truck Center.
G
Observe all safety instructions
and precautions when handling
automotive batteries.
A
Risk of explosion
D
Keep flames or sparks away
from battery. Do not smoke.
B
Battery acid is caustic. Do not
allow it to come into contact
with skin, eyes or clothing.
In case it does, immediately
flush affected area with clean
water and seek medical help if
necessary.
E
Wear eye protection.
C
Keep children away.
F
Follow the instructions in this
Operator’s Manual.
Page 489 of 561

488 Practical hintsBattery
!
The battery is a valve-regulated lead
acid (VRLA) battery, also referred to as
“fleece” battery. Such batteries do not
require topping-up of the electrolyte
level. VRLA batteries therefore do not
have cell caps and the battery cover is
non-removable. Do not attempt to
open the battery as otherwise the bat-
tery will be damaged.
Even though VRLA batteries do not
require topping-up of the electrolyte
level and cannot be opened to check
the electrolyte level, the battery condi-
tion must be checked periodically by
performing a battery conductance test.
Refer to Maintenance Booklet for bat-
tery condition testing intervals.
As with any other battery, the battery
may discharge if the vehicle is not
operated for an extended period of
time. You can connect a battery
maintenance charge unit tested and
approved for use on your vehicle model
or disconnected the battery to prevent
battery discharge. Contact an
authorized Mercedes-Benz Light Truck
Center for more information.
!The factory-equipped VRLA battery is
leak-proofed. Only use a battery as re-
placement that has the same security
features and is of identical size,
voltage, and capacity as the
factory-equipped battery.
The battery, the battery ventilation and
the lateral plug must always be
securely installed when the vehicle is in
operation.Warning!
G
Jump starting must only be done using the
jump-start contacts located in the engine
compartment (
page 496).
Page 490 of 561

489 Practical hints
Battery
Disconnecting, removing, reinstalling and reconnecting the battery
Warning!
G
Failure to follow these instructions can re-
sult in severe injury or death.
Observe all safety instructions and precau-
tions when handling automotive batteries
(page 487).
Never lean over batteries while connecting,
you might get injured.
Battery fluid contains sulfuric acid. Do not
allow this fluid to come in contact with eyes,
skin or clothing. In case it does, immediately
flush affected area with water and seek
medical help if necessary.
A battery will also produce hydrogen gas,
which is flammable and explosive. Keep
flames or sparks away from battery, avoid
improper connection of jumper cables,
smoking etc.
!Never loosen or detach battery termi-
nal clamps while the engine is running
or the SmartKey is in the starter switch.
Otherwise the alternator and other
electronic components could be se-
verely 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
also requires safety precautions to avoid the
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 per-
forming all of the tasks involved as de-
scribed in these instructions. Observe all
safety instructions and precautions when
handling automotive batteries
(page 487). 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.
Page 491 of 561

490 Practical hintsBatteryStep 1 (Disconnecting)
Set the automatic position to P
(page 199).
Firmly depress the parking brake
(page 65).
Turn off the engine (
page 66).
Leave the ignition switched on
(page 38).
Switch off all electrical consumers.
Read and observe safety instructions
and precautions (
page 487).
Open the front passenger door.
Move the front passenger seat to the
most rearward position (
page 43).Step 2 (Disconnecting)
1Seat rail covers, front right
2Seat rail covers, front left
Pull off right seat rail cover 1 in direc-
tion of arrow.
Pull left seat rail cover 2 in direction
of arrow as far as it will go.
Left seat rail cover 2 cannot be re-
moved.
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 vehi-
cle must be jump started (
page 496)
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 battery
charge unit*) before any of the follow-
ing steps can be performed. If the bat-
tery cannot be jumped or charged,
please contact an authorized
Mercedes-Benz Light Truck Center.
iOpen doors only when conditions are
safe to do so.
Page 492 of 561
491 Practical hints
Battery
3Battery cover mounting nuts
Using a 6 mm T-handle hex key (not
supplied with vehicle) with a minimum
shaft length of 12 in (30 cm), unfasten
and remove battery cover mounting
nuts 2 located at the floor carpet per-
foration.
Move the front passenger seat to the
most forward position (
page 43).
Switch off the ignition (
page 38).
Remove the SmartKey from the starter
switch.
Vehicles with KEYLESS-GO*:
Make sure the vehicle’s on-board
electronics have status 0.
After turning off the engine with the
KEYLESS-GO start/stop button,
with the driver's door closed, the
starter switch is in position1. With
the driver’s door opened, the start-
er switch is set to position0, same
as SmartKey removed from starter
switch (
page 39).Step 3 (Disconnecting)
4Seat rail, rear
5Seat rail cover, rear
Pull seat rail cover 5 away from seat
rail 4 on both sides as indicated by ar-
rows.
Pull off seat rail cover 5 to the rear as
indicated by arrow.