Page 448 of 585
447 Practical hints
What to do if …
Display symbol
Display message
Possible cause/consequence
Possible solution
#
Battery/Alternator
Stop vehicle
The battery is defective.
Stop the vehicle in a safe location or as
soon as it is safe to do so.
Apply the parking brake (
page 65).
Do not continue to drive.
Notify an authorized Mercedes-Benz
Light Truck Center.
y
inoperative
Downhill Speed Regulation is
malfunctioning.
Have the Downhill Speed Regulation
checked by an authorized Mercedes-Benz
Light Truck Center.
2
Brake wear
The brake pads have reached
their wear limit.
Have the brake pads replaced as soon as
possible.
!
Brake pad thickness must be visually in-
spected by a qualified technician at the intervals
specified in the Maintenance Booklet.
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Page 465 of 585
464 Practical hintsWhat to do if …Display symbol
Display messages
Possible cause/consequence
Possible solution
L
Tele Aid
inoperative
One or more main functions of the
Tele Aid* system are malfunctioning.
Have the Tele Aid* system checked
by an authorized Mercedes-Benz Light
Truck Center.
Tele Aid
battery
The emergency power battery for the
Tele Aid* system is malfunctioning. If the
vehicle battery is also malfunctioning or
drained, Tele Aid* will not be operational.
Have the Tele Aid* system checked
by an authorized Mercedes-Benz Light
Truck Center.
t
Function
unavailable
This display appears if buttont
ors on the multifunction steering
wheel is pressed and the vehicle is not
equipped with a telephone.
W
Top up
washer fluid
The fluid level has dropped to about
1/3 of
total reservoir capacity.
Add washer fluid (
page 363).
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Page 477 of 585

476 Practical hintsUnlocking/locking in an emergencyLocking 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 126).
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.
Unlocking and opening the tailgate
A minimum height clearance of 7.2 ft
(2.20 m) is required to open the tailgate.If the tailgate can no longer be unlocked
and opened using the Œbutton on the
SmartKey or the KEYLESS-GO* function,
use the manual release to unlock and open
the tailgate.
The manual release is located on the inside
of the tailgate.
1Release lever
2Cover
Remove cover2 from the trim on the
tailgate.
Push release lever1 all the way to the
left.
Lift the tailgate.
!
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.
i
This procedure does not arm the anti-theft
alarm system, nor does it lock the fuel filler flap.
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Page 481 of 585

480 Practical hintsReplacing SmartKey batteriesIf 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 475).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.
i
When inserting the batteries, make sure
they are clean and free of lint.
i
When replacing batteries, always replace
both batteries.
The required replacement batteries are available
at any Mercedes-Benz Light Truck Center.
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Page 482 of 585
481 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*.
ProCarManuals.com
Page 508 of 585

507 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.i
Mercedes-Benz recommends to have the
battery replaced at an authorized
Mercedes-Benz Light Truck Center.
Warning!
G
Observe all safety instructions and precau-
tions when handling automotive batteries.
Risk of explosion.
Fire, open flames and smoking
are prohibited when handling
batteries. Avoid creating sparks.
Battery acid is caustic. Do not
allow it to come into contact
with skin, eyes or clothing.
Wear suitable protective cloth-
ing, especially gloves, apron and
faceguard.
Wear eye protection.
Rinse any acid spills immediate-
ly with clear water. Contact a
physician if necessary.
Keep children away.
Follow the instructions in this
Operator’s Manual.
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Page 509 of 585

508 Practical hintsBattery!
The battery is a valve-regulated lead acid
(VRLA) battery, also referred to as “fleece” bat-
tery. 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 bat-
tery as otherwise the battery will be damaged.
Even though VRLA batteries do not require top-
ping-up of the electrolyte level and cannot be
opened to check the electrolyte level, the bat-
tery condition must be checked periodically by
performing a battery conductance test. Refer to
Maintenance Booklet for battery condition test-
ing intervals.
As with any other battery, the battery may dis-
charge if the vehicle is not operated for an ex-
tended period of time. You can connect a battery
maintenance charge unit tested and approved
for use on your vehicle model or disconnect 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 replacement
that has the same security features and is of
identical size, voltage, and capacity as the
factory-equipped battery.
The battery, the battery ventilation hose
(
page 513) and the lateral plug (
page 513)
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 515).
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 507).
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.
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Page 510 of 585

509 Practical hints
Battery
Disconnecting, removing, reinstalling and reconnecting the battery
Step 1 (Disconnecting)
Set the automatic transmission to
positionP (
page 187).
Firmly depress the parking brake
(page 65).
Turn off the engine (
page 66).
Leave the ignition switched on
(page 40).
!
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
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
performing all of the tasks involved as de-
scribed in these instructions. Observe all
safety instructions and precautions when
handling automotive batteries
(page 507). 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.
i
With 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.
i
If your battery is discharged, the vehicle
must be jump started (
page 515) 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.
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