fuel pressure MERCEDES-BENZ GLS 2017 User Guide

Avoid tire pressures that are too high in all the
tires, including the spare wheel.
Overinflated tires may: R
increase the braking distance R
adversely affect handling R
wear excessively and/or unevenly R
have an adverse effect on ride comfort R
be more susceptible to damage
Maximum tire pressures
C
Example: maximum permissible tire pres-
sure
Never exceed the maximum permissible tire
inflation pressure. Always observe the recom-
mended tire pressure for your vehicle when
adjusting the tire pressure ( Y
page 349).
i The actual values for tires are vehicle-spe-
cific and may deviate from the values in the
illustration.
Checking the tire pressures
Important safety notes Observe the notes on tire pressure
( Y
page 349).
Information on air pressure for the tires on your
vehicle can be found: R
on the Tire and Loading Information placard
on the B-pillar on the driver's side R
in the tire pressure table in the fuel filler flap R
in the "Tire pressure" section Checking tire pressures manually To determine and set the correct tire pressure,
proceed as follows: X
Remove the valve cap of the tire that is to be
checked. X
Press the tire pressure gage securely onto the
valve. X
Read the tire pressure and compare it to the
recommended value on the Tire and Loading
Information placard or the tire pressure table
( Y
page 349). X
If the tire pressure is too low, increase the tire
pressure to the recommended value. X
If the tire pressure is too high, release air. To
do so, press down the metal pin in the valve,
using the tip of a pen for example. Then check
the tire pressure again using the tire pressure
checker. X
Screw the valve cap onto the valve. X
Repeat these steps for the other tires.
Tire pressure loss warning system
General notes While the vehicle is in motion, the tire pressure
loss warning system monitors the set tire pres-
sure using the rotational speed of the wheels.
This enables the system to detect significant
pressure loss in a tire. If the speed of rotation of
a wheel changes as a result of a loss of pressure,
a corresponding warning message will appear in
the multifunction display.
You can recognize the tire pressure loss warning
by the Run Flat Indicator Active Press
'OK' to Restart message which appears in
the Service menu of the multifunction display.
Information on the message display can be
found in the "Restarting the tire pressure loss
warning system" section ( Y
page 353).
Important safety notes
The tire pressure warning system does not warn
you of an incorrectly set tire pressure. Observe
the notes on the recommended tire pressure
( Y
page 349).
The tire pressure loss warning does not replace
the need to regularly check the tire pressure. An
even loss of pressure on several tires at the352
Tire pressure
Wheels and tires

same time cannot be detected by the tire pres-
sure loss warning system.
The tire pressure monitor is not able to warn you
of a sudden loss of pressure, e.g. if the tire is
penetrated by a foreign object. In the event of a
sudden loss of pressure, bring the vehicle to a
halt by braking carefully. Avoid abrupt steering
movements.
The function of the tire pressure loss warning
system is limited or delayed if: R
snow chains are mounted on your vehicle's
tires. R
road conditions are wintry. R
you are driving on sand or gravel. R
you adopt a very sporty driving style (corner-
ing at high speeds or driving with high rates of
acceleration). R
you are driving with a heavy load (in the vehi-
cle or on the roof).
Restarting the tire pressure loss warn-
ing system Restart the tire pressure loss warning system if
you have: R
changed the tire pressure R
changed the wheels or tires R
mounted new wheels or tires X
Before restarting, make sure that the tire
pressures are set properly on all four tires for
the respective operating conditions.
The recommended tire pressure can be found
on the Tire and Loading Information placard
on the B-pillar. Additionally, a tire pressure
table is attached to the fuel filler flap. The tire
pressure loss warning system can only give
reliable warnings if you have set the correct
tire pressure. If an incorrect tire pressure is
set, these incorrect values will be monitored. X
Also observe the notes in the section on tire
pressures ( Y
page 349).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 Service menu.X
Press the c or d button to select
Tire Pressure .X
Press the v button.
The Run Flat Indicator Active Press
'OK' to Restart message appears in the
multifunction display. If you wish to confirm the restart: X
Press the v button.
The Tire Pressure Now OK? message
appears in the multifunction display. X
Press the c or d button to select Yes .X
Press the v button.
The Run Flat Indicator Restarted mes-
sage appears in the multifunction display.
After a teach-in period, the tire pressure loss
warning system will monitor the set tire pres-
sures of all four tires.
If you wish to cancel the restart: X
Press the 8 button.
or X
When the Tire Pressure Now OK? message
appears, press the c or d button to
select Cancel . X
Press the v button.
The tire pressure values stored at the last
restart will continue to be monitored.
Tire pressure monitor
General notes If a tire pressure monitor is installed, the vehi-
cle's wheels have sensors that monitor the tire
pressures in all four tires. The tire pressure mon-
itor warns you if the pressure drops in one or
more of the tires. The tire pressure monitor only
functions if the corresponding sensors are
installed in all wheels.
Information on tire pressures is displayed in the
multifunction display. After a few minutes of
driving, the current tire pressure of each tire is
shown in the Serv. menu of the multifunction
display, see illustration (example).
For information on the message display, refer to
the "Checking the tire pressure electronically"
section ( Y
page 355).Tire pressure 353
Wheels and tires Z

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

You can find more tire pressure values for
various operating conditions in the tire pres-
sure table inside the fuel filler flap
( Y
page 349).X
Make sure that the tire pressure is correct on
all four wheels. X
Make sure that the SmartKey is in position 2
in the ignition lock. 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 multifunction display shows the current
tire pressure for the individual tires or the
Tire pressure will be displayed
after driving a few minutes message.X
Press the d button.
The Use Current Pressures as New Ref‐
erence Values message appears in the mul-
tifunction display.
If you wish to confirm the restart: X
Press the v button.
The Tire Press. Monitor Restarted mes-
sage appears in the multifunction display.
After driving for a few minutes, the system
checks whether the current tire pressures are
within the specified range. The new tire pres-
sures are then accepted as reference values
and monitored.
If you wish to cancel the restart: X
Press the 8 button.
The tire pressure values stored at the last
restart will continue to be monitored.
Radio type approval for the tire pres-
sure monitor Country Radio type approval number
USA FCC ID: MRXMW2433A
FCC ID: MRXGG4
FCC ID: MRXMC34MA4
Canada IC: 2546A-MW2433A
IC: 2546A-GG4
IC: 2546A-MC34MA4 Loading the vehicle
Instruction labels for tires and loads
G WARNING
Overloaded tires can overheat, causing a
blowout. Overloaded tires can also impair the
steering and driving characteristics and lead
to brake failure. There is a risk of accident.
Observe the load rating of the tires. The load
rating must be at least half of the GAWR of
your vehicle. Never overload the tires by
exceeding the maximum load.
Two instruction labels on your vehicle show the
maximum possible load.
(1) The Tire and Loading Information placard is
on the B-pillar on the driver's side. The Tire
and Loading Information placard shows the
maximum permissible number of occu-
pants and the maximum permissible vehicle
load. It also contains details of the tire sizes
and corresponding pressures for tires
mounted at the factory.
(2) The vehicle identification plate is on the B-
pillar on the driver's side. The vehicle iden-
tification plate informs you of the gross
vehicle weight rating. It is made up of the
vehicle weight, all vehicle occupants, the
fuel and the cargo. You can also find infor-
mation about the maximum gross axle
weight rating on the front and rear axle.
The maximum gross axle weight rating is
the maximum weight that can be carried by
one axle (front or rear axle). Never exceed
the maximum load or the maximum gross
axle weight rating for the front or rear axle.356
Loading the vehicle
Wheels and tires

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