2017 MERCEDES-BENZ GLA-Class tire pressure

when the low tire pressure telltale lights up,
you should stop and check your tires as soonas possible, and inflate them to the proper
pressure. Driving on a significantly underin-
flated tire causes the tire to overheat and can
lead to tire failure.
Underinflation also reduces fuel efficiency
and tire tread life, and may affect the vehicle's
handling and stopping ability. Please note that the TPMS is not a substitute for proper tire
maintenance, and it is the driver's responsi-
bility to maintain correct tire pressure, even if
underinflation has not reached the level to
trigger illumination of the TPMS low tire pres-
sure telltale.
Your vehicle has also been equipped with a
TPMS malfunction indicator to indicate when
the system is not operating properly. The
TPMS malfunction indicator is combined withthe low tire pressure telltale. When the sys-
tem detects a malfunction, the warning lamp
will flash for approximately a minute and then
remain continuously illuminated. This
sequence will be repeated every time the vehi-
cle is started as long as the malfunction
exists. When the malfunction indicator is illu-
minated, the system may not be able to detect
or signal low tire pressure as intended.
TPMS malfunctions may occur for a variety of
reasons, including the installation of incom-
patible replacement or alternate tires or
wheels on the vehicle that prevent the TPMS
from functioning properly. Always check the
TPMS malfunction tellt
ale after replacing one
or more tires or wheels on your vehicle to
ensure that the replacement or alternate Tires
and wheels allow the TPMS to continue to
function properly.
It is the driver's responsibility to set the tire
pressure to that recommended for cold tires
which is suitable for the operating situation
(
Ypage 343). Note that the correct tire pres-
sure for the current operating situation must
first be taught-in to the tire pressure monitor.
If there is a substantial loss of pressure, the
warning threshold for the warning message is aligned to the reference values taught-in.
Restart the tire pressure monitor after adjust-
ing the pressure of the cold tires
(
Ypage 350). The current pressures are
saved as new reference values. As a result, a
warning message will appear if the tire pres-
sure drops significantly.
The tire pressure monitor does not warn you
of an incorrectly set tire pressure. Observe
the notes on the recommended tire pressure
(
Ypage 343).
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 tire pressure monitor has a yellow warn-
ing lamp in the instrument cluster for indicat-
ing pressure loss or a malfunction. Whet her
t

he warning lamp flashes or lights up indi-
cates whether a tire pressure is too low or the
tire pressure monitor is malfunctioning:
Rif the warning lamp is lit continuously, the
tire pressure on one or more tires is signif-
icantly too low. The tire pressure monitor is not malfunctioning.
Rif the warning lamp flashes for around a
minute and then remains lit constantly, the
tire pressure monitor is malfunctioning.
In addition to the warning lamp, a message
appears in the multifunction display. Observe
the information on display messages
(
Ypage 258).
It may take up to ten minutes for a malfunc-
tion of the tire pressure monitor to be indica-
ted. A malfunction will be indicated by the tire
pressure warning lamp flashing for approx-
imately 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
Tire pressure349
Wheels and tires
Z

computer refer to those measured at sea
level. At high altitudes, the tire pressure val-
ues 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 trans-
mitting equipment (e.g. radio headphones,
two-way radios) that may be being operated
in or near the vehicle.
Checking the tire pressure electroni-
cally
XMake sure that the SmartKey is in position
2in the ignition lock (
Ypage 149).
XPress =or; on the steering wheel
to select the Serv.
menu.
XPress the9or: button to select
Tire Pressure
.
XPress the abutton.
The current tire pressure of each tire is
shown in the multifunction display.
If the vehicle was parked for longer than
20 minutes, the Tire pressure will be
displayed after driving a few
minutesmessage is shown.
After a teach-in process, the tire pressure
monitor 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 Activemessage is shown instead
of the tire pressure display. The tire pressures are already being monitored.
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 yel-
low tire pressure warning lamp then lights up.
RIf the Please Correct Tire Pressure
message appears in the multifunction dis-
play, the tire pressure in at least one tire is too low. The tire pressure must be correc-
ted when the opportunity arises.
RIf the
Check Tire Pressuremessage
appears in the multifunction display, the
tire pressure in one or more tires has drop-
ped significantly. The tires must be
checked.
RIf the Tire Pressure Warning Tire
Failuremessage appears in the multi-
function display, the tire pressure in one or
more tires has dropped suddenly. The tires
must be checked.
Observe the instructions and safety notes in
the display messages in the "Tires" section
(
Ypage 258).
If the wheel positions on the vehicle are rota-
ted, 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 pressures are displayed for the cor-
rect 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 currently set tire pressures as the refer-
ence values for monitoring. In most cases, the
tire pressure monitor will automatically
detect the new reference values after you
have changed the tire pressure. However, you
can also define reference values manually as described here. The tire pressure monitor
then monitors the new tire pressure values.
XSet the tire pressure to the value recom-
mended for the corresponding driving sit-
uation on the Tire and Loading Information
placard on the driver's side
B-pillar (
Ypage 343).
You can find more tire pressure values for
various operating conditions in the tire
pressure table inside the fuel filler flap
(
Ypage 170).
XMake sure that the tire pressure is correct
on all four wheels.
350Tire pressure
Wheels and tires

XMake sure that the SmartKey is in position2 in the ignition lock (
Ypage 149).
XPress =or; on the steering wheel
to select the Serv.
menu.
XPress the9or: button to select
Tire Pressure
.
XPress the abutton.
The multifunction display shows the cur-
rent tire pressure for each tire or the Tire
pressure will be displayed after
driving a few minutesmessage.
XPress the:button.
The multifunction display shows the Use
CurrentPressuresasNewReference
Valuesmessage.
If you wish to confirm the restart:
XPress the abutton.
The Tire Press. Monitor Restarted
message appears in the multifunction dis-
play.
After driving for a few minutes, the system
checks whether the current tire pressures
are within the specified range. The new tire
pressures are then accepted as reference
values and monitored.
If you wish to cancel the restart:
XPress the %button.
The tire pressure values stored at the last
restart will continue to be monitored.
Radio type approval for the tire pres-
sure monitor
CountryRadio type approval number
USAFCC ID: MRXMW2433A
FCC ID: MRXGG4
FCC ID: MRXMC34MA4
CanadaIC: 2546A-MW2433A
IC: 2546A-GG4
IC: 2546A-MC34MA4
Loading the vehicle
Instruction labels for tires and loads
GWARNING
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 occupants and the maximum permis-
sible vehicle load. It also contains details
of the tire sizes and corresponding pres-
sures for tires mounted at the factory.
(2) The vehicle identification plate is on the B-pillar on the driver's side. The vehicle
identification plate informs you of the
gross vehicle weight rating. It is made up
of the vehicle weight, all vehicle occu-
pants, the fuel and the cargo. You can
also find information 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 maxi-
mum gross axle weight rating for the
front or rear axle.
Loading the vehicle351
Wheels and tires
Z

Tire labeling
Overview
:Uniform Tire Quality Grading Standards
(
Ypage 361)
;Department of Transportation, Tire Iden-
tification Number (
Ypage 360)
=Maximum load rating (Ypage 359)
?Maximum tire pressures (Ypage 346)
AManufacturer
BTire material (Ypage 360)
CTire size designation, load-bearing capa-
city and speed rating (
Ypage 357)
DLoad index (Ypage 359)
ETire name
The markings described above are on the tire
in addition to the tire name (sales designa-
tion) and the manufacturer's name.
iTire data is vehicle-specific and may devi-
ate from the data in the example.
Tire size designation, load-bearing
capacity and speed rating
GWARNING
Exceeding the stated tire load-bearing capa-
city and the approved maximum speed could
lead to tire damage or the tire bursting. There is a risk of accident.
Therefore, only use tire types and sizes
approved for your vehicle model. Observe the
tire load rating and speed rating required for
your vehicle.
:Tire width
;Nominal aspect ratio in %
=Tire code
?Rim diameter
ALoad bearing index
BSpeed rating
General: depending on the manufacturer's
standards, the size imprinted in the tire wall
may not contain any letters or may contain
one letter that precedes the size description.
If there is no letter preceding the size descrip-
tion (as shown above): these are passenger
vehicle tires according to European manufac-
turing standards.
If "P" precedes the size description: these are
passenger vehicle tires according to U.S.
manufacturing standards.
If "LT" precedes the size description: these
are light truck tires according to U.S. manu-
facturing standards.
If "T" precedes the size description: compactemergency wheels with high tire pressure
that are only designed for temporary use in an
emergency.
Tire width: tire width:shows the nominal
tire width in millimeters.
Aspect ratio: aspect ratio;is the size ratio
between the tire height and tire width and is
shown in percent. The aspect ratio is calcu-
All about wheels an d tires357
Wheels and tires
Z

All-weather tires and winter tires
IndexSpeedrating
Q M+S1up to 100 mph (160 km/h)
T M+S1up to 118 mph (190 km/h)
H M+S1up to 130 mph (210 km/h)
V M+S1up to 149 mph (240 km/h)
iNot all tires with the M+S marking provide
the driv ing characteristics of winter tires. In
addit ion to the M+S marking, winter tires
also have the isnowflake symbol on
the tire wall.Tires with this marking fulfill
the requirements of the Rubber Manufac-
turers Association (RMA) and the Rubber
Association of Canada (RAC) regarding the
tire traction on snow. They have been espe-
cial lydeveloped for driving on snow.
An electronic speed limiter prevents your
veh icle from exceeding a speed of 130 mph
(21 0km/ h).
The speed rating of tires mounted at the fac-
tory may be higher than the maximum speed
that the electronic speed limiter permits.
Make sure that your tires have the required
speed rating, e.g. when buying new tires. The
required speed rating for your vehicle can be
found in the "Tires" section (
Ypage 367).
Further information about reading tire data
can be obtained from any qualified specialist workshop.
Load index
In addition to the load-bearing index, load
index :may be imprinted after the letters
that identify speed rating on the sidewall of
the tire. Speed rating (
Ypage 357).
RIf no specification is given: no text (as in the
example above), represents a standard
load (SL) tire
RXL or Extra Load: represents a reinforced
tire
RLight Load: represents a light load tire
RC, D, E: represents a load range that
depends on the maximum load that the tire
can carry at a certain pressure
iTire data is vehicle-specific and may devi-
ate from the data in the example.
Maximum load rating
Maximum tire load :is the maximum per-
missible weight for which the tire is approved.
Do not overload the tires by exceeding the
specified load limit. The maximum permissi-
1Or M+S ifor winter tires.
All about wheels and tires359
Wheels and tires
Z

ble load can be found on the vehicle's Tire and
Loading Information placard on the B-pillar on
the driver's side (
Ypage 351).
iThe actual values for tires are vehicle-
specific and may deviate from the values in
the illustration.
DOT, Tire Identification Number (TIN)
US tire regulations stipulate that every tire
manufacturer or retreader must imprint a TIN
in or on the sidewall of each tire produced.
The TIN is a unique identification number. The
TIN enables the tire manufacturers or retread-
ers to inform purchasers of recalls and other
safety-relevant matters. It makes it possible
for the purchaser to easily identify the affec-
ted tires.
The TIN is made up of manufacturer identifi-
cation code ;, tire size=, tire type code ?
and manufacturing date A.
DOT (Department of Transportation): tire
symbol :marks that the tire complies with
the requirements of the U.S. Department of
Transportation.
Manufacturer identification code: manu-
facturer identification code ;provides
details on the tire manufacturer. New tires
have a code with two symbols. Retreaded
tires have a code with four symbols.
For further information about retreaded tires,
see (
Ypage 367).
Tire size: identifier=describes the tire size. Tire type code:
tire type code?can be used
by the manufacturer as a code to describe
specific characteristics of the tire.
Date of manufacture: date of manufacture
A provides information about the age of a
tire. The first and second positions represent
the week of manufacture, starting with "01"
for the first calendar week. Positions three
and four represent the year of manufacture.
For example, a tire that is marked with
"3208", was manufactured in week 32 in
2008.
iTire data is vehicle-specific and may devi-
ate from the data in the example.
Tire characteristics
This information describes the type of tire
cord and the number of layers in sidewall :
and under tire tread ;.
iTire data is vehicle-specific and may devi-
ate from the data in the example.
Definition of terms for tires and loading
Tire ply composition and material used
Describes the number of plies or the number
of layers of rubber-coated fabric in the tire
tread and sidewall. These are made of steel,
nylon, polyester and other materials.
Bar
Metric unit for tire pressure. 14.5038 pounds
per square inch (psi) and 100 kilopascals
(kPa) are the equivalent of 1 bar.
360All about wheels and tires
Wheels and tires

DOT (Department of Transportation)
DOT-markedtires fulfill th erequirements of
th e U S Departmen tof Transportation .
Normal occupant weigh t
The number of occupant sfo rwhic hth evehi-
cle is designed multiplie dby 68 kilograms
(15 0lbs) .
Unifor mTire Qualit yGrading Standards
A uniform standard to grade th equalit yof
tires wit hregards to tread quality, tire traction
and temperature characteristics .The qualit y
gradin gassessmen tis made by th emanufac -
turer following specification sfrom th eU.S.
government. The ratings are molded into th e
sidewall of th etire.
Recommended tire pressure s
The recommended tire pressur eapplies to
th etires mounted at th efactory.
The Tir eand Loadin gInformation placard con-
tains th erecommended tire pressures fo r
cold tires on afull yloade dvehicl eand fo rth e
maximum permissibl evehicl espeed.
The tire pressur etable contain sth erecom-
mended pressures fo rcold tires fo rvarious
operating conditions, i.e. differin gload and
speed conditions.
Increased vehicle weigh tdu eto optiona l
equipment
The combine dweight of all standard and
optional equipmen tavailable fo rth evehicle,
regardless of whether it is a
ctually installed
on th evehicl eor not.
Ri m
This is th epart of th ewhee lon whic hth etire
is mounted.
GAW R(Gross Axle Weight Rating)
The GAW Ris th emaximum gross axl eweight
rating. The actual load on an axl emus tnever
exceed th egross axl eweight rating. The
gross axl eweight ratin gcan be found on th e
vehicl eidentification plat eon th eB-pillar on
th edriver's side . Speed rating
The speed ratin
gis part of th etire identifica-
tion .It specifies th espeed range fo rwhic hth e
tire is approved.
GV W(Gross Vehicle Weight )
The gross vehicl eweight includes th eweight
of th evehicl eincludin gfuel ,tools ,th espar e
wheel, accessories installed ,occupants, lug-
gage and th edrawbar noseweight ,if applica-
ble. The gross vehicl eweight mus tno texceed
th egross vehicl eweight ratin gGVWR as
specified on th evehicl eidentification plat eon
th eB-pillar on th edriver's side .
GVWR (Gross Vehicle Weight Rating)
The GVWR is th emaximum permissibl egross
weight of afull yloade dvehicl e(the weight of
th evehicl eincludin gall accessories, occu-
pants ,fuel, luggage and th edrawbar nose-
weight ,if applicable). The gross vehicl e
weight ratin gis specified on th
eve
hicl eiden -
tification plat eon th eB-pillar on th edriver's
side .
Maximum loaded vehicle weigh t
The maximum weight is th esum of :
Rthecur bweight of th evehicl e
Rtheweight of th eaccessories
Rth eload limi t
Rtheweight of th efactory installed optional
equipmen t
Kilopascal (kPa)
Metric uni tfo rtire pressure. 6. 9kP acorre-
spond sto 1psi .Another uni tfo rtire pressur e
is bar. 10 0kilopascal s(kPa) are th eequiva-
len tof 1bar.
Load index
In addition to th eload-bearin gindex ,th eload
index may also be imprinte don th esidewall of
th etire. This specifies th eload-bearin gcapa-
cit ymor eprecisely.
All about wheels and tires36 1
Wheels and tires
Z

Curb weight
The weight of a vehicle with standard equip-
ment including the maximum capacity of fuel,
oil and coolant. It also includes the air-condi-
tioning system and optional equipment if
these are installed in the vehicle, but does not
include passengers or luggage.
Maximum load rating
The maximum tire load is the maximum per-
missible 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
outward force to each square inch of the tire's
surface. 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:
Rif the vehicle has been parked with the tires
out of direct sunlight for at least three
hours and
Rif 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 sit
s
securely on t

he wheel. There are several steel
wires in the bead to prevent the tire from
coming loose from the wheel rim.
Sidewall
The part of the tire between the tread and the bead.
Weight of optional extras
The combined weight of those optional extras
that weigh more than the replaced standard
parts and more than 2.3 kg (5 lbs). These
optional extras, such as high-performance
brakes, level control, a roof rack or a high-
performance battery, are not included in the
curb weight and the weight of the accesso-
ries.
TIN (Tire Identification Number)
This is a unique identifier which can be used
by a tire manufacturer to identify tires, for
example for a product recall, and thus identify
the purchasers. The TIN is made up of the
manufacturer's identity code, tire size, tire
type code and the manufacturing date.
Load bearing index
The load bearing index (also load index) is a
code that contains the maximum load bearing
capacity of a tire.
Traction
Traction is the result of friction between the
tires and the road surface.
Treadwear indicators
Narrow bars (tread wear bars) that are dis-
tributed over the tire tread. If the tire tread is
level with the bars, the wear limit of áin
(1.6 mm) has been reached.
362All about wheels and tires
Wheels and tires