2018 MERCEDES-BENZ GLS engine

Battery (vehicle)
12 V battery - important safety notes Special tools and expert knowledge are required
when working on the battery, e.g. removal and
installation. You should therefore have all work
involving the battery carried out at a qualified
specialist workshop.
G WARNING
Work carried out incorrectly on the battery
can lead, for example, to a short circuit and
thus damage the vehicle electronics. This can
lead to function restrictions applying to
safety-relevant systems, e.g. the lighting sys-
tem, the ABS (anti-lock braking system) or the
ESP ®
(Electronic Stability Program). The oper-
ating safety of your vehicle may be restricted.
You could lose control of the vehicle, for
example: R
when braking R
in the event of abrupt steering maneuvers
and/or when the vehicle's speed is not
adapted to the road conditions
There is a risk of an accident.
In the event of a short circuit or a similar inci-
dent, contact a qualified specialist workshop
immediately. Do not drive any further. You
should have all work involving the battery car-
ried out at a qualified specialist workshop.
For further information about ABS and ESP ®
,
see ( Y
page 66) and ( Y
page 69).
G WARNING
Electrostatic build-up can lead to the creation
of sparks, which could ignite the highly explo-
sive gases of a battery. There is a risk of an
explosion.
Before handling the battery, touch the vehicle
body to remove any existing electrostatic
build-up.
The highly flammable gas mixture forms when
charging the battery as well as when jump-start-
ing. Always make sure that neither you nor the bat-
tery is electrostatically charged. A build-up of
electrostatic charge can be caused, for exam-
ple: R
by wearing clothing made from synthetic
fibers R
due to friction between clothing and seats R
if you push or pull the battery across the car-
pet or other synthetic materials R
if you wipe the battery with a cloth
G WARNING
During the charging process, a battery produ-
ces 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 con-
tact with vehicle parts. R
Never place metal objects or tools on a bat-
tery. R
It is important that you observe the descri-
bed 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 dis-
connecting the jumper cables. R
Never connect or disconnect the battery
terminals while the engine is running.
G WARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with skin, eyes or clothing. Do
not inhale any battery gases. Do not lean over
the battery. Keep children away from batter-
ies. Wash away battery acid immediately with
plenty of clean water and seek medical atten-
tion.
H Environmental note
Batteries contain dangerous
substances. It is against the
law to dispose of them with344
Battery (vehicle)
Breakdo wn assis tance

Charging the 12 V 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, open 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 skin, eyes or clothing. Do
not inhale any battery gases. Do not lean over
the battery. Keep children away from batter-
ies. Wash away battery acid immediately with
plenty of clean water and seek medical atten-
tion.
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 use battery chargers with a maximum
charging voltage of 14.8 V. ! Only charge the battery using the jump-
starting connection point.
The jump-starting connection point is in the
engine compartment ( Y
page 346).X
Open the hood. X
Connect the battery charger to the positive
terminal and ground point in the same order
as when connecting the donor battery in the
jump-starting procedure ( Y
page 346).
Keep away from fire and open flames. Do not
lean over a battery. Never charge the battery if it
is still installed in the vehicle, unless you use a
battery charger which has been tested and
approved by Mercedes-Benz. A battery charger
unit specially adapted for Mercedes-Benz vehi-
cles and tested and approved by Mercedes-
Benz is available as an accessory. It permits the
charging of the battery in its installed position.
Contact an authorized Mercedes-Benz Center
for further information and availabilit y. Read t he
batt ery charger's operating instructions before
charging the battery.
If, at low temperatures, the indicator lamps/
warning lamps in the instrument cluster do not
light up, it is highly likely that the discharged
battery has frozen. In this case you may neither
jump-start the vehicle nor charge the battery.
The service life of a thawed-out battery may be
shorter. The starting characteristics can be
impaired, particularly at low temperatures. Have
the thawed-out battery checked at a qualified
specialist workshop.
Jump-starting
For the jump-starting procedure, use only the jump-starting connection point in the engine com-
partment, consisting of a positive terminal and a ground point.
G WARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with skin, eyes or clothing. Do not inhale any battery gases. Do not lean over the
battery. Keep children away from batteries. Wash away battery acid immediately with plenty of
clean water and seek medical attention.
G WARNING
During charging and jump-starting, explosive gases can escape from the battery. There is a risk
of an explosion.346
Jump-starting
Breakdown assistance

Particularly avoid fire, open flames, creating sparks and smoking. Ensure there is sufficient ven-
tilation 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 jumper cables. R
Never connect or disconnect the battery terminals while the engine is running.
G WARNING
A discharged 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.
! Vehicles with a gasoline engine: avoid repeated and lengthy starting attempts. Otherwise, the
catalytic converter could be damaged by non-combusted fuel.
If the indicator/warning lamps do not light up at low temperatures, it is very likely that the dis-
charged battery has frozen. In this case you may neither jump-start the vehicle nor charge the
battery. The service life of a thawed-out battery may be shorter. The starting characteristics can be
impaired, particularly at low temperatures. Have the thawed-out battery checked at a qualified
specialist workshop.
Do not start the vehicle using a rapid charging device. If your vehicle's battery is discharged, the
engine can be jump-started from another vehicle or from a donor battery using jumper cables.
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 donor battery or a jump-starting device. R
Vehicles with a gasoline engine: only jump-start the 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
Only jump-start from batteries with a 12 V voltage rating. R
Only use jumper cables which 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 battery slightly. R
Make sure that the two vehicles do not touch. Jump-starting 347
Breakdown assistance Z

Make sure that: R
The jumper cables are not damaged. R
Bare parts of the terminal clamp do not come into contact with other metal parts while the jumper
cables are connected to the battery. R
The jumper cables cannot come into contact with parts which can move when the engine is
running, such as the V-belt pulley or the fan. X
Secure the vehicle by applying the electric parking brake. X
Shift the transmission to position ] .X
Make sure that the ignition is switched off. All indicator lamps in the instrument cluster must be
off. When using the SmartKey, turn the SmartKey to position

i Jumper cables and further information regarding jump-starting can be obtained at any qualified
specialist workshop.
Towing and tow-starting
Important safety notes
G WARNING
Functions relevant to safety are restricted or
no longer available if: R
the engine is not running. R
the brake system or the power steering is
malfunctioning. R
there is a malfunction in the voltage supply
or the vehicle's electrical system.
If your vehicle is being towed, much more
force may be necessary to steer or brake.
There is a risk of an accident.
In such cases, use a tow bar. Before towing,
make sure that the steering moves freely.
G WARNING
When towing or tow-starting another vehicle
and its weight is greater than the permissible
gross weight of your vehicle, the: R
the towing eye could detach itself R
the vehicle/trailer combination could roll-
over.
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.
Details on the permissible gross vehicle weight
of your vehicle can be found on the vehicle iden-
tification plate ( Y
page 385).
! When Active Brake Assist, Distance Pilot
DISTRONIC or the HOLD function is activated,
the vehicle brakes automatically in certain
situations.
To avoid damage to the vehicle, deactivate
these systems in the following or similar sit-
uations: R
when towing the vehicle R
in the car wash ! Make sure that the electric parking brake is
released. If the electric parking brake is faulty,
visit a qualified specialist workshop.
! Only secure the tow rope or tow bar at the
towing eyes, or the trailer tow hitch, if availa-
ble. You could otherwise damage the vehicle.
! Observe the following points when towing
with a tow rope: R
Secure the tow rope on the same side on
both vehicles. R
Make sure that the tow rope is not longer
than legally permitted. Mark the tow rope in
the middle, e.g. with a white c loth
(1
1.8 x 11.8 in). This will make other road
users aware that a vehicle is being towed. R
Only secure the tow cable to the towing
eyes or, if available, to the trailer tow hitch. R
Observe the brake lamps of the towing
vehicle while driving. Always maintain a dis-
tance a distance so that the tow rope does
not sag. R
Do not use steel cables or chains to tow
your vehicle. You could otherwise damage
the vehicle.
! Do not use the trailer tow hitch for recovery
or towing. Do not use the towing eye for
recovery. this could damage the vehicle. If in
doubt, have the vehicle recovered using a
crane.
! When towing, pull away slowly and
smoothly. Pull the towed vehicle as straight as
possible and not at an acute angle. Excessive
tractive power could damage the vehicles.
When towing, it is preferable to use a rigid tow-
ing bar as opposed to a tow rope. A rigid towing
bar helps to keep the tractive power low.
! When towing away vehicles with KEYLESS-
GO, use the key instead of the Start/Stop
button. The automatic transmission may oth-
erwise shift to position ] when you open the
driver's or front-passenger door, which could
damage the transmission.
! Do not tow with sling-type equipment. This
could damage the vehicle.Towing and tow-starting 349
Breakdown assistance Z

Vehicles with 4MATIC may either be towed away
with both axles on the ground or be loaded up
and transported.
If the vehicle's transmission, front, or rear axle is
damaged, have the vehicle transported on a
truck or trailer.
In the event of damage to the electrical sys-
tem: if the battery is defective, the automatic
transmission will be locked in position P . To shift
the automatic transmission to position N , you
must provide power to the vehicle's electrical
system in the same way as when jump-starting
( Y
page 346).
Have the vehicle transported on a transporter or
trailer.
Tow-starting (emergency engine
starting)
! Vehicles with automatic transmission must
not be tow-started. You could otherwise dam-
age the automatic transmission.
You can find information on "Jump-starting"
under ( Y
page 346).
Fuses
Important safety notes
G WARNING
If you manipulate or bridge a faulty fuse or if
you replace it with a fuse with a higher amper-
age, the electric cables could be overloaded.
This could result in a fire. There is a risk of an
accident and injury.
Always replace faulty fuses with the specified
new fuses having the correct amperage.
! For the fuse boxes in the engine compart-
ment and under the rear bench seat, only use
fuses with the suffix "S". Otherwise, compo-
nents or systems could be damaged.
! Make sure that no moisture can enter the
fuse box when the cover is open.
! When closing the cover, make sure that it is
lying correctly on the fuse box. Moisture seep-
ing in or dirt could otherwise impair the oper-
ation of the fuses. The fuses in your vehicle serve to close down
faulty circuits. If a fuse blows, all the compo-
nents on the circuit and their functions stop
operating.
Blown fuses must be replaced with fuses of the
same rating, which you can recognize by the
color and value. The fuse ratings are listed in the
fuse allocation chart.
The fuse allocation chart is located in the fuse
box under the rear bench seat ( Y
page 353).
If a newly inserted fuse also blows, have the
cause traced and rectified at a qualified special-
ist workshop, e.g. an authorized Mercedes-Benz
Center.
Before changing a fuse Observe the important safety notes
( Y
page 352) X
Switch off the engine. X
Switch off all electrical consumers. X
Remove the SmartKey from the ignition lock.
Or, on vehicles with KEYLESS-GO start function
or KEYLESS ‑ GO: X
Open the driver's door.
The vehicle electronics are now in key posi-
tion

shop, e.g. at an authorized Mercedes-Benz Cen-
ter.
X
Open the front-passenger door. X
To open: pull cover C outwards in the direc-
tion of the arrow and remove it. X
To close: clip in cover C on the front of the
dashboard. X
Fold cover C inwards until it engages.
Fuse box in the engine compartment
G WARNING
When the hood is open and the windshield
wipers are set in motion, you can be injured by
the wiper linkage. There is a risk of injury.
Always switch off the windshield wipers and
the ignition before opening the hood.
X
Open the hood ( Y
page 325).X
Use a dry cloth to remove any moisture from
the fuse box. X
To open: open clamps D .X
Fold up cover C in the direction of the arrow
and remove it. X
To close: check whether the seal is seated
correctly in cover C .X
Insert cover C at the side of the fuse box into
the retainers. X
Fold down cover C and close clamps D .X
Close the hood.
Fuse box under the rear bench seat X
Fold the left-hand rear bench seat forward
( Y
page 303). X
To open: reach into recesses D on each side
of fuse box cover C .X
Fold cover C up in the direction of the arrow
and remove it from the fuse box.
i The fuse allocation chart is located in a
recess at the side of the fuse box. X
To close: place cover C on the fuse box.X
Press cover C down until you feel the clamps
engage. X
Fold back the left-hand rear bench seat
( Y
page 303). Fuses 353
Breakdown assistance Z

be required earlier. Do not change the direction
of wheel rotation.
Clean the contact surfaces of the wheel and the
brake disc thoroughly every time a wheel is rota-
ted. Check the tire pressure and, if necessary,
restart the tire pressure loss warning system or
the tire pressure monitor ( Y
page 361).
Direction of rotation Tires with a specified direction of rotation have
additional benefits, e.g. if there is a risk of hydro-
planing. These advantages can only be gained if
the tires are installed corresponding to the
direction of rotation.
An arrow on the sidewall of the tire indicates its
correct direction of rotation.
Storing wheels Store wheels that are not being used in a cool,
dry and preferably dark place. Protect the tires
from oil, grease, gasoline and diesel.
Mounting a wheel
Preparing the vehicle X
Vehicle with emergency spare wheel:
when mounting the emergency spare wheel in
the event of a flat tire, follow the additional
notes on vehicle preparation under "Flat tire"
( Y
page 339). X
Stop the vehicle on solid, non-slippery and
level ground. X
Apply the electric parking brake manually. X
Bring the front wheels into the straight-ahead
position. X
Vehicles with automatic transmission:
shift the transmission to position ] .X
Vehicles with the AIRMATIC package:
make sure that the normal vehicle level is
selected ( Y
page 190).X
Vehicles with the Off-Road Engineering
package: make sure that the normal level is
selected ( Y
page 184).X
Switch off the engine. X
Vehicles without KEYLESS-GO: remove the
SmartKey from the ignition lock. X
Vehicles with KEYLESS-GO: open the driv-
er's door.
The vehicle electronics are now in position