light MERCEDES-BENZ GLS 2017 Owners Manual

The vehicle will then use very little energy, thus
conserving battery power.
If the power supply has been interrupted, e.g. if
you reconnect the battery, you will have to: R
set the clock; see the Digital Operator's Man-
ual
On vehicles with a multimedia system and
navigation system, the clock is set automati-
cally. R
reset the function for folding the exterior mir-
rors in/out automatically, by folding the mir-
rors out once ( Y
page 108).
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 338).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 338).
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 availability. Read the
battery 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.338
Jump-starting
Breakdown assistance

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.
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 second 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 second 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. Jump-starting 339
Breakdo wn assis tance Z

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.
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 P .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 0 in the ignition lock and remove it
( Y
page 138).X
Switch off all electrical consumers, e.g. rear window defroster, lighting, etc. X
Open the hood.
Position number

Further information on tire pressures can be
obtained at a qualified specialist workshop.
Tire and Loading Information placard
C
Recommended tire pressures
The Tire and Loading Information placard is on
the B-pillar on the driver's side ( Y
page 356).
The Tire and Loading Information placard con-
tains the recommended tire pressures for cold
tires. The recommended tire pressures are valid
for the maximum permissible load and up to the
maximum permissible vehicle speed.
Tire pressure table The tire pressure table is on the inside of the fuel
filler flap. It shows the tire pressure for all tires
permitted at the factory for this vehicle; see
illustration (example).
The tire pressure table contains the recommen-
ded pressures for cold tires for various operat-
ing conditions, i.e. differing load and speed con-
ditions.
If a tire size precedes a tire pressure, the fol-
lowing tire pressure information is only valid for
that tire size; see illustration (example). The load conditions "partially laden" and "fully
laden" are defined in the table for different num-
bers of occupants and amounts of luggage. The
actual number of seats may differ.
Some tire pressure tables show only the rim
diameters instead of the full tire size, e.g. R18 .
The rim diameter is part of the tire size and can
be found on the tire sidewall ( Y
page 361).
If the tire pressures have been set to the lower
values for lighter loads and/or lower road
speeds, the pressures should be reset to the
higher values: R
if you want to drive with an increased load
and/or R
if you want to drive at higher road speeds
The tire pressures for increased loads and/or
higher road speeds, shown in the tire pressure
table, may have a negative effect on driving
comfort.
If the tire pressure is not set correctly, this can
lead to an excessive build up of heat and a sud-
den loss of pressure.
For more information, contact a qualified spe-
cialist workshop.350
Tire pressure
Wheels and tires

Important safety notes
G WARNIN G
Eac h tire, includin g th e spar e (if provided),
should be checke d at least once a month
when cold and inflated to th e pressur e rec -
ommended by th e vehicl e manufacturer on
th e Tir e and Loading Information placard on
th e driver' s door B-pillar or th e tire pressur e
label on th e inside of th e fuel filler flap . If your
vehicl e has tires of a differen t siz e than th e
siz e indicated on th e Tir e and Loading Infor -
mation placard or th e tire pressur e label, you
should determine th e proper tire pressur e for
those tires .
As an added safet y feature, your vehicl e has
been equipped wit h a tire pressur e monitoring
system (TPMS) that illuminate s a low tire pres-
sur e telltale when on e or mor e of your tires
are significantly underinflated. Accordingly,
when th e low tire pressur e telltale illuminates,
you should stop and chec k your tires as soo n
as possible , and inflat e them to th e proper
pressure. Drivin g on a significantly underin-
flated tire causes th e tire to overheat and can
lead to tire failure. Underinflation also
reduce s fuel efficiency and tire tread life , and
may affec t th e vehicle's handlin g and stop-
pin g ability.
Pleas e note that th e TPM S is no t a substitut e
for proper tire maintenance
, a nd it is th e d riv -
er' s responsibilit y to maintai n correc t tire
pressure, eve n if underinflation has no t
reached th e level to trigge r illumination of th e
TPM S low tire pressur e telltale.
US A only:
Your vehicl e has also been equipped wit h a
TPM S malfunction indicator to indicat e if th e
system is no t operating properly. The TPM S
malfunction indicator is combined wit h th e
low tire pressur e telltale. When th e system
detects a malfunction , th e warning lamp will
flas h for approximately a minute and then
remain continuously illuminated. This
sequenc e will be repeated every time th e vehi-
cle is started as lon g as th e malfunction
exists. When th e malfunction indicator is illuminated,
th e system may no t be able to detec t or signal
low tire pressur e as intended. TPM S malfunc -
tion s may occur for a variet y of reasons,
includin g th e mounting of incompatible
replacemen t or alternate tires or wheels on
th e vehicl e that preven t th e TPM S from func-
tioning properly. Always chec k th e TPM S mal-
function telltale after replacing on e or mor e
tires or wheels on your vehicl e to ensur e that
th e replacemen t or alternate tires and wheels
allow th e TPM S to continue to function prop-
erly.
It is th e driver' s responsibilit y to set th e tire
pressur e to that recommended for cold tires
whic h is suitable for th e operating situation
( Y
page 349). Not e that th e correc t tire pressur e
for th e curren t operating situation must first be
taught-in to th e tire pressur e monitor. If there is
a substantial loss of pressure, th e warning
threshold for th e warning message is aligned to
th e referenc e value s taught-in . Restart th e tire
pressur e monitor after adjusting th e pressur e of
th e cold tires ( Y
page 355). The curren t pres-
sures are saved as ne w referenc e values. As a
result , a warning message will appear if th e tire
pressur e d rops significantly.
T he tire pressur e monitor does no t warn you of
an incorrectl y set tire pressure. Observ e th e
note s on th e recommended tire pressur e
( Y
page 349).
The tire pressur e monitor is no t able to warn you
of a sudde n loss of pressure, e.g. if th e tire is
penetrated by a foreign object. In th e event of a
sudde n loss of pressure, brin g th e vehicl e to a
halt by braking carefully. Avoid abrup t steering
movements.
The tire pressur e monitor has a yellow warning
lamp in th e instrumen t cluste r for indicating
pressur e loss or a malfunction . Whether th e
warning lamp flashes or lights up indicates
whether a tire pressur e is to o low or th e tire
pressur e monitor is malfunctioning :R
if th e warning lamp is lit continuously, th e tire
pressur e on on e or mor e tires is significantly
to o low. The tire pressur e monitor is no t mal-
functioning . R
if th e warning lamp flashes for aroun d a
minute and then remain s lit constantly, th e
tire pressur e monitor is malfunctioning .354
Tire pressure
Wheels and tires

In addition to the warning lamp, a message
appears in the multifunction display. Observe
the information on display messages
( Y
page 268).
It may take up to ten minutes for a malfunction
of the tire pressure monitor to be indicated. A
malfunction will be indicated by the tire pres-
sure warning lamp flashing for approximately
one minute and then remaining lit. When the
malfunction has been rectified, the tire pressure
warning lamp goes out after a few minutes of
driving.
The tire pressure values indicated by the on-
board computer may differ from those meas-
ured at a gas station with a pressure gauge. The
tire pressures shown by the on-board computer
refer to those measured at sea level. At high
altitudes, the tire pressure values indicated by a
pressure gauge are higher than those shown by
the on-board computer. In this case, do not
reduce the tire pressures.
The operation of the tire pressure monitor can
be affected by interference from radio transmit-
ting equipment (e.g. radio headphones, two-way
radios) that may be being operated in or near the
vehicle.
Checking the tire pressure electroni-
cally X
Make sure that the SmartKey is in position 2
in the ignition lock ( Y
page 138).X
Press the Y or e button on the steering
wheel to select the Serv. menu.X
Press the c or d button to select
Tire Pressure .X
Press the v button.
The current tire pressure of each tire is shown
in the multifunction display.
If the vehicle has been parked for longer than
20 minutes, the Tire pressure will be
displayed after driving a few minutes
message appears.
After a teach-in process, the tire pressure mon-
itor automatically detects new wheels or new
sensors. As long as a clear allocation of the tire
pressure value to the individual wheels is not
possible, the Tire Pressure Monitor Active
display message is shown instead of the tire
pressure display. The tire pressures are already
being monitored.
If an emergency spare wheel is mounted, the
system may continue to show the tire pressure of the wheel that has been removed for a few
minutes. If this occurs, note that the value dis-
played for the position where the spare wheel is
mounted is not the same as the current tire
pressure of the emergency spare wheel.
Tire pressure monitor warning mes-
sages If the tire pressure monitor detects a pressure
loss in one or more tires, a warning message is
shown in the multifunction display. The yellow
tire pressure warning lamp then lights up. R
If the Please Correct Tire Pressure
message appears in the multifunction display,
the tire pressure in at least one tire is too low.
The tire pressure must be corrected when the
opportunity arises. R
If the Check Tires message appears in the
multifunction display, the tire pressure in at
least one tire has dropped significantly. The
tires must be checked. R
If the Warning Tire Malfunction message
appears in the multifunction display, the tire
pressure in at least one tire has dropped sud-
denly. The tires must be checked.
Be sure to observe the instructions and safety
notes in the display messages in the "Tires" sec-
tion ( Y
page 268).
If the wheel positions on the vehicle are rotated,
the tire pressures may be displayed for the
wrong positions for a short time. This is rectified
after a few minutes of driving, and the tire pres-
sures are displayed for the correct positions.
Restarting the tire pressure monitor When you restart the tire pressure monitor, all
existing warning messages are deleted and the
warning lamps go out. The monitor uses the cur-
rently set tire pressures as the reference values
for monitoring. In most cases, the tire pressure
monitor will automatically detect the new refer-
ence values after you have changed the tire
pressure. However, you can also define refer-
ence values manually as described here. The tire
pressure monitor then monitors the new tire
pressure values. X
Set the tire pressure to the value recommen-
ded for the corresponding driving situation on
the Tire and Loading Information placard on
the driver's side B-pillar ( Y
page 349).Tire pressure 355
Wheels and tires Z

Speed rating The speed rating is part of the tire identification.
It specifies the speed range for which the tire is
approved.
GTW (Gross Trailer Weight) The GTW is the weight of a trailer including the
weight of the load, luggage, accessories etc. on
the trailer.
GVW (Gross Vehicle Weight) The gross vehicle weight includes the weight of
the vehicle including fuel, tools, the spare wheel,
accessories installed, occupants, luggage and
the drawbar noseweight, if applicable. The gross
vehicle weight must not exceed the gross vehi-
cle weight rating GVWR as specified on the vehi-
cle identification plate on the B-pillar on the
driver's side.
GVWR (Gross Vehicle Weight Rating) The GVWR is the maximum permissible gross
weight of a fully loaded vehicle (the weight of the
vehicle including all accessories, occupants,
fuel, luggage and the drawbar noseweight, if
applicable). The gross vehicle weight rating is
specified on the vehicle identification plate on
the B-pillar on the driver's side.
Maximum loaded vehicle weight The maximum weight is the sum of: R
the curb weight of the vehicle R
the weight of the accessories R
the load limit R
the weight of the factory installed optional
equipment
Kilopascal (kPa)
Metric unit for tire pressure. 6.9 kPa corre-
sponds to 1 psi. Another unit for tire pressure is
bar. 100 kilopascals (kPa) are the equivalent of
1 bar.
Load index
In addition to the load-bearing index, the load
index may also be imprinted on the sidewall of
the tire. This specifies the load-bearing capacity
more precisely.
Curb weight
The weight of a vehicle with standard equipment
including the maximum capacity of fuel, oil and
coolant. It also includes the air-conditioning sys- tem and optional equipment if these are instal-
led in the vehicle, but does not include passen-
gers or luggage.
Maximum load rating The maximum tire load is the maximum permis-
sible weight in kilograms or lbs for which a tire is
approved.
Maximum permissible tire pressure Maximum permissible tire pressure for one tire.
Maximum load on one tire Maximum load on one tire. This is calculated by
dividing the maximum axle load of one axle by
two.
PSI (pounds per square inch) A standard unit of measure for tire pressure.
Aspect ratio Relationship between tire height and tire width
in percent.
Tire pressure This is pressure inside the tire applying an out-
ward force to each square inch of the tire's sur-
face. The tire pressure is specified in pounds per
square inch (psi), in kilopascal (kPa) or in bar.
The tire pressure should only be corrected when
the tires are cold.
Cold tire pressure The tires are cold: R
if the vehicle has been parked with the tires
out of direct sunlight for at least three hours
and R
if the vehicle has not been driven further than
1 mile (1.6 km)
Tread
The part of the tire that comes into contact with
the road.
Bead
The tire bead ensures that the tire sits securely
on the wheel. There are several steel wires in the
bead to prevent the tire from coming loose from
the wheel rim.All about wheels and tires 365
Wheels and tires Z