2015 MERCEDES-BENZ GLA-Class tire pressure

minute and then remaining lit. When the mal-
function 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 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 X
Make sure that the SmartKey is in position
2 in the ignition lock (Y page 143).
X Press the 0059or0065 button on the steer-
ing wheel to select the Serv.
Serv. menu.
X Press the 0063or0064 button to select
Tire Pressure Tire Pressure .
X Press the 0076button.
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
Tire pressure will be
displayed after driving a few
displayed after driving a few
minutes minutes message 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
Tire Pressure
Monitor Active Monitor Active message 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 and the yellow tire pressure monitor warning light
comes on.
R If the Correct Tire Pressure Correct Tire Pressure message
appears in the multifunction display, the
tire pressure in at least one tire is too low
and must be corrected at the next oppor-
tunity.
R If the Check Tire Pressure Soon Check Tire Pressure Soon mes-
sage appears in the multifunction display,
the tire pressure in one or more tires has
dropped significantly and the tires must be checked.
R If the Tire Pressure Warning Tire Tire Pressure Warning Tire
Failure
Failure message appears in the multi-
function display, the tire pressure in one or
more tires has dropped suddenly and the
tires must be checked.
Observe the instructions and safety notes in
the display messages in the "Tires" section
(Y page 245).
i If the wheel positions on the vehicle are
rotated, the tire pressures may be dis-
played for the wrong positions for a short
time. This is rectified after a few minutes of driving, and the tire pressures are displayedfor 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 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. 334
Tire pressureWheels and tires

X
Set 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 (Y page 328).
Additional tire pressure values for different loads can also be found on the tire pressure
table on the inside of the fuel filler flap
(Y page 328).
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 0059or0065 button on the steer-
ing wheel to select the Serv. Serv.menu.
X Press the 0063or0064 button to select
Tire Pressure
Tire Pressure.
X Press the 0076button.
The multifunction display shows the cur-
rent tire pressure for each tire or the Tire Tire
pressure will be displayed after
pressure will be displayed after
driving a few minutes driving a few minutes message.
X Press the 0064button.
The multifunction display shows the Use
Use
current
current pressures
pressures as
asnew
new reference
reference
values
values message.
If you wish to confirm the restart:
X Press the 0076button.
The Tire Press. Monitor Restarted
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:
X Press the 0038button.
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. 0043
B-pillar, driver's side
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 Loading the vehicle
335Wheels and tires Z

Temperature
G
WARNING
The temperature grade for this tire is estab-
lished for a tire that is properly inflated and
not overloaded. Excessive speed, underinfla-
tion, or excessive loading, either separately or
in combination, can cause excessive heat
build-up and possible tire failure.
The temperature grades are A (the highest), B,
and C. These represent the tire's resistance
to the generation of heat and its ability to dis- sipate heat when tested under controlled
conditions on a specified indoor laboratory
test wheel. Sustained high temperature can
cause the material of the tire to degenerate
and reduce tire life, and excessive tempera-
ture can lead to sudden tire failure. The grade
C corresponds to a level of performance
which all passenger car tires must meet under the Federal Motor Vehicle Safety Standard
No. 109. Grades B and A represent higher
levels of performance on the laboratory test
wheel than the minimum required by law. Tire labeling
Overview of tire labeling
The following markings are on the tire in addition to
the tire name (sales designation) and the manu-
facturer's name:
0043 Uniform tire Quality Grading Standard
(Ypage 345)
0044 DOT, Tire Identification Number
(Ypage 344)
0087 Maximum tire load (Y page 339)
0085 Maximum tire pressure (Y page 330)
0083 Manufacturer
0084 Tire material (Y page 345)
006B Tire size designation, load-bearing capa-
city and speed index (Y page 342)
006C Load index (Y page 344)
006D Tire name
i Tire data is vehicle-specific and may devi-
ate from the data in the example. Tire labeling
341Wheels and tires Z

Tire size designation, load-bearing
capacity and speed rating 0043
Tire width
0044 Nominal aspect ratio in %
0087 Tire code
0085 Rim diameter
0083 Load bearing index
0084 Speed rating
i Tire data is vehicle-specific and may devi-
ate from the data in the example.
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: these are
compact emergency spare wheels at high tire pressure, to be used only temporarily in an
emergency.
Tire width: tire width0043shows the nominal
tire width in millimeters.
Nominal aspect ratio: aspect ratio0044is the
size ratio between the tire height and the tire width and is shown in percent. The aspect ratio is calculated by dividing the tire width by
the tire height.
Tire code: tire code0087specifies the tire type.
"R" represents radial tires; "D" represents
diagonal tires; "B" represents diagonal radial
tires.
Optionally, tires with a maximum speed of
over 149mph (24 0km/h) may have "ZR" in
the size description, depending on the man-
ufacturer (e.g. 245/40 ZR 18).
Rim diameter: rim diameter0085is the diam-
eter of the bead seat, not the diameter of the
rim flange. The rim diameter is specified in
inches (in).
Load bearing index: load bearing index0083is
a numerical code which specifies the maxi-
mum load-bearing capacity of a tire.
Do not overload the tires by exceeding the
specified load limit. The maximum permissi-
ble load can be found on the vehicle's Tire and
Loading Information placard on the B-pillar on the driver's side (Y page 335).
Example:
A load-bearing index of 91 indicates a maxi-
mum load of 1,356lb (615kg) that can be car-
ried by the tires. For further information on
the maximum tire load in kilograms and
pounds, see (Y page 339).
For further information on the load-bearing
index, see Load index (Y page 344).
Speed rating: speed rating0084specifies the
approved maximum speed of the tire. G
WARNING
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.
Regardless of the speed rating, always
observe the speed limits. Drive carefully and 342
Tire labelingWheels and tires

Load index
In addition to the load bearing index, load
index 0043may be imprinted after the letters
that identify speed index 0084(Ypage 342) on
the sidewall of the tire.
R If no specification is given: no text (as in the
example above), represents a standard
load (SL) tire
R XL or Extra Load: represents a reinforced
tire
R Light Load: represents a light load tire
R C, D, E: represents a load range that
depends on the maximum load that the tire can carry at a certain pressure
i Tire data is vehicle-specific and may devi-
ate from the data in the example. DOT, Tire Identification Number (TIN)
Canadian tire regulations prescribe that every
new tire manufacturer or retreader has to
imprint a TIN in or on the sidewall of each tire
produced. The TIN is a unique identification number. The
TIN makes it easier for tire manufacturers or
retreaders to notify customers of recalls or
other safety-related matters. It makes it pos- sible for the purchaser to easily identify the
affected tires.
The TIN consists of the manufacturer identi-
fication code 0044, tire size0087, tire type
code 0085and manufacturing date 0083.
DOT (Department of Transportation): tire
symbol 0043indicates that the tire complies
with the requirements of the Canadian Trans-
port Ministry.
Manufacturer identification code: manu-
facturer identification code 0044provides
details on the tire manufacturer. New tires
have a code with two symbols. Retreaded
tires have a code with four symbols.
Further information about retreaded tires
(Y page 324).
Tire size: identifier0087describes the tire size.
Tire type code: tire type code0085can be used
by the manufacturer as a code to describe
specific characteristics of the tire.
Date of manufacture: date of manufacture
0083 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.
i Tire data is vehicle-specific and may devi-
ate from the data in the example. 344
Tire labelingWheels and tires

Tire characteristics
This information describes the tire cord and
the number of layers in sidewall 0043and under
tire tread 0044.
i Tire data is vehicle-specific and may devi-
ate from the data in the example. Definition of terms for tires and load-
ing
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. DOT (Department of Transportation)
DOT marked tires fulfill the requirements of
the Canadian Transport Ministry. Normal occupant weight
The number of occupants for which the vehi-
cle is designed multiplied by 68 kilograms
(150 lb). Uniform Tire Quality Grading Stand-
ards
A uniform standard to grade the quality of
tires with regards to tread quality, tire traction and temperature characteristics. Ratings are determined by tire manufacturers using U.S.
government testing procedures. The ratings
are molded into the sidewall of the tire. Recommended tire pressure
The recommended tire pressure applies to
the tires mounted at the factory.
The Tire and Loading Information placard con-
tains the recommended tire pressures for
cold tires on a fully loaded vehicle and for the maximum permissible vehicle speed.
The tire pressure table contains the recom-
mended pressures for cold tires for various
operating conditions, i.e. differing load and
speed conditions. Increased vehicle weight due to
optional equipment
This is the combined weight of all standard
and optional equipment available for the vehi-
cle, regardless of whether it is actually instal-
led on the vehicle or not. Rim
This is the part of the wheel on which the tire
is mounted. GAWR (Gross Axle Weight Rating)
The GAWR is the maximum gross axle weight
rating. The actual load on an axle must never exceed the gross axle weight rating. The
gross axle weight rating can be found on the
vehicle identification plate on the B-pillar on
the driver's side. Definition of
terms for tires and loading
345Wheels and tires Z

Speed rating
The speed rating is part of the tire identifica-
tion. It specifies the speed range for which the tire is approved. GVW (Gross Vehicle Weight)
The gross vehicle weight includes the weight
of the vehicle including fuel, tools, the spare
wheel, accessories installed, occupants, lug-
gage and the drawbar noseweight, if applica- ble. The gross vehicle weight must not exceed
the gross vehicle weight rating GVWR as
specified on the vehicle 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, occu-
pants, fuel, luggage and the drawbar nose-
weight, if applicable). The gross vehicle
weight rating is specified on the vehicle iden-
tification 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 kilopascal (kPa) is 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 capa- city more precisely. 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 load rating in kilograms or
pounds is the maximum weight 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. 346
Definition of terms for tires and loadingWheels and tires

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. Tire pressure of cold tires
The tires are cold:
R if the vehicle has been parked without
direct sunlight on the tires 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. 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
part 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 00CDin
(1.6 mm) has been reached. Occupant distribution
The distribution of occupants in a vehicle at
their designated seating positions. Total load limit
Nominal load and luggage load plus
68 kilograms (150 lb) multiplied by the num-
ber of seats in the vehicle. Changing a wheel
Flat tire
You can find information on what to do in the
event of a flat tire in the "Flat tire" section
(Y page 306). Information on driving with
MOExtended tires in the event of a flat tire can Changing a
wheel
347Wheels an d tires Z