battery MERCEDES-BENZ G-CLASS SUV 2012 Service Manual

In order for the battery to achieve the maxi-
mum possible service life, it must always be
sufficiently charged.
Comply with safety precautions and take pro-
tective measures when handling batteries. WARNING
Avoid the creation of sparks and
heat.
Avoid fire, naked flames and smok-
ing. Creation of sparks.
Battery acid is caustic.
Avoid contact with the skin, eyes
or clothing.
Wear eye protection.
Keep childre
naway. Observe this Owner's Manual.
The vehicle battery, like other batteries, can
discharge over time if you do not use the
vehicle. In such cases, have the battery dis-
connected at a qualified specialist workshop.
You can also charge the battery with a
charger recommended by Mercedes-Benz.
For more information, please contac taquali-
fied specialist workshop.
Explosive gases are created during charging
and jump-starting.
For safety reasons, Mercedes-Benz recom-
mends that you only use batteries which have
been tested and approved for your vehicle by
Mercedes-Benz .These batteries provide
increased impact protection to prevent vehi-
cle occupants from suffering acid burns
should the battery be damaged in the event
of an accident.
Have the battery charge checked more fre-
quently if you use the vehicle mainly for short trips or if you leave it standing idle for a
lengthy period. Consult a qualified specialist
workshop if you wish to leave your vehicle
parked up for a long period of time.
i
When you park the vehicle, remove the
key if you do not require any electrical con-
sumers. The vehicle will then use very little
energy, thus conserving battery power.
i If the power supply has been interrupted,
e.g. due to a discharged battery, you will
have to:
R set the clock. Information on setting the
clock can be found in the separate oper-
ating instructions.
On vehicles with COMAND Online and a
navigation system, the clock is set auto-
matically.
R reset the head restraints on the front
seats (Y page 93).
R reset the function for folding the exterior
mirrors in/out automatically, by folding
the mirrors out once (Y page 100). Charging the battery
G
WARNING
During charging and jump-starting, explosive
gases can escape from the battery. There is a
risk of an explosion.
Particularly avoid fire, naked flames, creating
sparks and smoking. Ensure there is sufficient
ventilation while charging and jump-starting.
Do not lean over a battery. G
WARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with the skin, eyes or clothing.
Do not inhale any battery gases. Do not lean
over the battery. Keep children away from
batteries. Wash battery acid immediately with
water and seek medical attention. Battery (vehicle)
311Breakdown assistance Z

G
WARNING
A discharged battery can freeze at tempera-
tures below freezing point. When jump-start-
ing the vehicle or charging the battery, gases
can escape from the battery .There is a risk of
an explosion.
Allow the frozen battery to thaw out before
charging it or jump-starting.
! Only charge the installed battery with a
battery charger which has been tested and
approved by Mercedes-Benz. These battery
chargers allow the battery to be charged
while still installed in the vehicle.
! Only use battery chargers with a maxi-
mum charging voltage of 14.8 V.
! Only charge the battery using the jump-
start connection point.
Never charge a battery still installed in the
vehicle unless a battery charger unit
approved by Mercedes-Ben zis being used.
Ab attery charge runit specially adapted for
Mercedes-Benz vehicles and tested and
approved by Mercedes-Benz is available as an
accessory .Itpermits the charging of the bat-
tery in its installed position .Contact a
Mercedes-Benz Service Centre for informa-
tion and availability. Charge the battery in
accordance with the separate instructions for
the battery charger.
The jump-starting connection point is in the
engine compartment (Y page 313).
Read the battery charger's operating instruc-
tions before charging the battery.
X Open the bonnet (Y page 291).
X Connect the battery charger to the positive
terminal and earth point in the same order
as when connecting the donor battery in
the jump-starting procedure
(Y page 313). 312
Battery (vehicle)Breakdown assistance

Jump-starting
G
WARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with the skin, eyes or clothing. Do not inhale any battery gases. Do not lean over
the battery. Keep children away from batteries. Wash battery acid immediately with water and
seek medical attention. G
WARNING
Gases escaping from the battery during jump-starting may cause minor explosions. Avoid cre-
ating sparks. Keep naked flames away from the battery, and do not smoke.
Comply with the important safety precautions when handling batteries. You will find these under
"Battery (vehicle) -important safety notes" in the index. G
WARNING
During charging and jump-starting, explosive gases can escape from the battery .There is a risk
of an explosion.
Particularly avoid fire, naked flames, creating sparks and smoking. Ensure there is sufficient
ventilation while charging and jump-starting. Do not lean over a battery. G
WARNING
During the charging process, a battery produces hydrogen gas. If a short circuit occurs or sparks
are created, the hydrogen gas can ignite. There is a risk of an explosion.
R Make sure that the positive terminal of a connected battery does not come into contact with
vehicle parts.
R Never place metal objects or tools on a battery.
R It is important that you observe the described order of the battery terminals when connecting
and disconnecting a battery.
R When jump-starting, make sure that the battery poles with identical polarity are connected.
R It is particularly important to observe the described order when connecting and disconnecting
the jump leads.
R Never connect or disconnect the battery terminals while the engine is running. G
WARNING
Ad ischarged battery can freeze at temperatures below freezing point .When jump-starting the
vehicle or charging the battery, gases can escape from the battery. There is a risk of an explosion.
Allow the frozen battery to thaw out before charging it or jump-starting. G
WARNING
Non-combusted fuel can collect in the exhaust system and ignite. There is a risk of fire. Avoid
repeated and lengthy starting attempts.
! Avoid repeated and lengthy starting attempts. Otherwise, non-combusted fuel may dam-
age the catalytic converter and create a risk of fire. Jump-starting
313Breakdown assistance Z

Do not use a rapid charging device to start the vehicle.
Make sure the jump leads are not damaged.
Make sure the jump leads are not touching any other metal objects when they are connected
to the battery.
If the indicator/warning lamps do not ligh tup at temperatures around or below freezing point,
the discharged battery is likely to be frozen (a commonplace scenario). In this case, do not
jump-start the vehicle or recharge the battery.
Once the battery has thawed out, its service life may be dramatically reduced.
The starting characteristic scan be impaired, particularly at low temperatures.
It is recommended that you have the thawed out battery checked at a qualified specialist
workshop.
Do no tuse a rapid charging device to start the vehicle. If your vehicle's battery is discharged,
the engine can be jump-started from another vehicle or from a second battery using jump
leads. Observe the following points:
R The battery is not accessible in all vehicles. If the other vehicle's battery is not accessible,
jump-start the vehicle using a second battery or ajump-starting device.
R Vehicles with apetrol engine: only jump-star tthe vehicle when the engine and exhaust
system are cold.
R Do not start the engine if the battery is frozen. Let the battery thaw first.
R Jump-starting may only be performed from batteries with a nominal voltage of 12 V.
R Only use jump leads that have a sufficient cross-section and insulated terminal clamps.
R If the battery is fully discharged, leave the battery that is being used to jump-start connected
for a few minutes before attempting to start. This charges the empty battery a little.
R Make sure that the two vehicles do not touch.
Make sure that:
R The jump leads are not damaged.
R Non-insulated parts of the terminal clamps do not come into contact with other metal parts
while the jump leads are connected to the battery.
R The jump leads cannot come into contact with parts such as the pulley or the fan. These
parts move when the engine is started and while it is running.
X Apply the parking brake.
X Move the selector lever to P.
X Switch off all electrical consumers (e.g. radio, blower, etc.).
X Open the bonnet (Y page 291).314
Jump-startingBreakdown assistance

Position number
Bidentifies the charged battery of the other vehicle or an equivalent jump-
starting device.
The jump-start terminal point consists of terminals ;and ?.
X Lift up cover :of positive terminal ;in the direction of the arrow.
X Connec tpositive terminal ;on your vehicle to positive terminal ?of donor battery B
using the jump lead. Begin with your own battery.
X Start the engine of the donor vehicle and run it at idling speed.
X Connect negative terminal Aof donor battery Bto earth point =of your vehicle using
the jump lead, connectingt he jump lead to donor battery Bfirst.
X Start the engine.
X First, remove the jump lead from earth point =and negative terminal A, then from positive
terminal ;and positive terminal ?, each time disconnecting from the battery on your own
vehicle first.
X Have the battery checked at a qualified specialist workshop.
i Jump-starting is not considered to be a normal operating condition.
i Jump-starting cables and further information regarding jump-starting can be obtained at
any qualified specialist workshop. Towing and tow-starting
Important safety notes
G
WARNING
The vehicle is braked when the HOLD function
or DISTRONIC PLUS is activated. Therefore, deactivate HOLD and DISTRONIC PLUS if the
vehicle is to be towed.
! You may tow the vehicle for a maximum
of 50km. A towing speed of 50 km/h must
not be exceeded. Towing and tow-starting
315Breakdown assistance Z

For towing distances over 50 km, the entire
vehicle mus
tbe lifted up and transported.
! Only secure the tow cable or towing bar
to the towing eyes. You could otherwise
damage the vehicle.
! Do not use the towing eyes for recovery
purposes as this could damage the vehicle.
If in doubt, recover the vehicle with a crane.
! When towing, pull away slowly and
smoothly. If the tractive power is too high,
the vehicles could be damaged.
! Your vehicles is equipped with an auto-
matic transmission .Therefore, you must
not have the vehicle tow-started. The trans-
mission may otherwise be damaged. G
WARNING
If the weight of the vehicle to be towed or tow-
started is greater than the permissible gross
weight of your vehicle:
R the towing eye could detach itself
R the vehicle/trailer combination could over-
turn.
There is a risk of an accident.
When towing or tow-starting another vehicle,
its weight should not be greater than the per-
missible gross weight of your vehicle.
Information on your vehicle's gross vehicle
weight rating can be found on the vehicle
identification plate (Y page 340).
Observe the legal requirements for the rele-
vant countries when towing.
It is better to have the vehicle transported
than to have it towed.
If the transfer case can be shifted into neutral
N, you can tow the vehicle.
If the transfer case cannot be shifted into
neutral N, you can tow the vehicle with one
axle raised. Please bear the following in mind:
R remove the propeller shaft between the
transfer case and the rolling axle.
R turn the key to position 1in the ignition lock
(Y page 143). The battery must be connected and charged.
Otherwise, you:
R
cannot turn the key in the ignition lock to
position 2(Ypage 143)
R cannot shift the automatic transmission to
position N
i Deactivate the automatic locking feature
(Y page 74). You could otherwise be locked
out when pushing or towing the vehicle.
Deactivate tow-away protection before the
vehicle is towed (Y page 65). Towing eyes
Towing eyes, front :
Towing eyes, front
Towing eye, rear Rear towing eye
:is located under the
bumper, on the left-hand side when viewed in
the direction of travel. 316
Towing and tow-startingBreakdown assistance

Towing the vehicle with both axles on
the ground
It is important tha tyou observe the safety
instructions when towing away your vehicle
(Y page 315).
X Switch on the hazard warning lamps
(Y page 109).
i In order to signal a change of direction
when towing the vehicle with the hazard
warning lamps switched on, use the com-
bination switch as usual.Int his case, only
the turn signals for the desired direction
flash. When you reset the combination
switch, the hazard warning lamps start
flashing again.
X Turn the key to position 2in the ignition
lock (Y page 143).
X When the vehicle is stationary, depress the
brake pedal and keep it depressed.
X Shift the transfer case to neu-
tral(Y page 203).
X Shift the automatic transmission to posi-
tion N.
X Release the brake pedal.
X Release the parking brake (Y page 164).
i The transmission can only change gear
when the battery has sufficient charge.
If you cannot move the selector lever to N,
you must remove the propeller shafts to the
driven axles. Transporting the vehicle
! Only lash the vehicle down by the wheels
or wheel rims, not by parts of the vehicle
such as axle or steering components. Oth-
erwise, the vehicle could be damaged.
Use the towing eyes to pull the vehicle if it
needs to be transported on a trailer or trans-
porter (Y page 316).
X Apply the parking brake.
X Turn the key to position 2in the ignition
lock (Y page 143). X
Move the selector lever to N.
X Shift the transfer case to neu-
tral(Y page 203).
X Secure the towing cable to the towing eyes
(Y page 316).
X Make sure that the vehicle cannot roll
away.
X Release the parking brake.
X Load the vehicle onto the transporter.
As soon as the vehicle is loaded:
X Apply the parking brake.
X Shift the automatic transmission to posi-
tion P.
X Turn the key to position 0in the ignition
lock (Y page 143) and remove it.
X Secure the vehicle. Recovering
avehicle that has become
stuck
! When recovering a trapped vehicle, do not
jerk the vehicle or pull it at an angle. If the
tractive power is too high, the vehicles
could be damaged.
If the drive wheels get trapped on loose or
muddy ground, recover th evehicle with the
utmost care, especially so if the vehicle is
laden.
Never attempt to recover a vehicle with a
trailer attached.
Pull out the vehicle backwards, if possible,
using the tracks it made when it became
stuck. Towing in the event of malfunctions
General notes !
If you are removing the propeller shaft,
use M10 nuts as spacers on the M8 bolts
and secure them with M8 nuts.
New self-locking nuts must be used when
the propeller shafts are refitted. Towing and tow-starting
317Breakdown assistance Z

X
Observe the safety notes as you do so
(Y page 315).
i Consult a Mercedes-Benz Service Centre.
Engine damage, gear damage or electri-
cal faults X
Move the selector lever to posi-
tion N(Y page 149).
X Shift the transfer case to neu-
tral (Ypage 203).
In the event of damage to the transfer
case Have the propellers
hafts between the axles
and the transfer case removed.
In the event of damage to the front axle Have the propeller shaft between the rear
axle and the transfer case removed.
Have the vehicle towed with the front axle
raised.
In the event of damage to the rear axle
Have the propeller shaft between the front
axle and the transfer case removed.
Then, have the vehicle towed with the rear
axle raised and with wheel rollers under the
front axle.
Electrical fuses
Important safety notes
G
WARNING
Only use fuses that have been approved for
Mercedes-Ben zvehicles and which have the
correct fuse rating for the systems con-
cerned. Do not attempt to repair or bridge
faulty fuses. Using fuses which have not been
approved or attempting to repair or bridge
faulty fuses could cause the fuse to be over-
loaded and result in a fire. Have the cause traced and rectified at a qualified specialist
workshop.
! Only use fuses that have been approved
for Mercedes-Benz vehicles and which
have the correct fuse rating for the system
concerned. Otherwise, components or sys-
tems could be damaged.
The fuses in your vehicle serve to disconnect
faulty circuits. If afuse blows, all the compo-
nents on the circuit and their functions will
fail.
Blown fuses must be replace dwith fuses of
the same rating, which you can recognise by
the colour and fuse rating. The fuse ratings
are listed in the fuse allocation chart.
If the newly inserted fuse also blows, have the
cause traced and rectified at a qualified spe-
cialist workshop, e.g. a Mercedes-Benz
Service Centre. Before replacing a fuse
X Park the vehicle and apply the parking
brake.
X Switch off all electrical consumers.
X Remove the key from the ignition lock.
All indicator lamps in the instrumen tcluster
must be off.
The fuses are located in various fuse boxes:
R Main fuse box on the driver's side of the
dashboard
R Fuse box in the front-passenger footwell
R Fuse box in the transmission tunnel
R Fuse box in the battery case
The fuse allocation char tand the spare fuses
are in the main fuse bo xonthe dashboard
(Y page 319).
You will find the fuse removal device in the
vehicle tool kit (Y page 306).318
Electrical fusesBreakdown assistance

X
Fold dow nthe cup holder on the centre
console (Y page 275).
X Adjust the front-passenger seat to its fore-
most position (Y page 92).
X To open: remove screws :.
X Remove cover ;in the direction of the
arrow.
X To close: clip in cover ;.
X Fit cover ;with screws :. Fuse box in the battery case
The fuses in the battery case do not usually
need to be replaced. If a fuse change is nec-
essary, consult a qualified specialist work-
shop. 320
Electrical fusesBreakdown assistance