warning MERCEDES-BENZ GLC 2019 Owners Manual

off-road or on rough roads. Damaged wheelscan cause a loss of tire pressure.
Pay particular attention to damage such as:
RCuts in the tires
RPunctures in the tires
RTears in the tires
RBulges on tires
RDeformation or severe corrosion on wheels
Regularly check the tire tread depth and thecondition of the tread across the whole width ofthe tire (Ypage 331). If necessary, turn thefront wheels to full lock in order to inspect theinner side of the tire surface.
All wheels must have a valve cap to protect thevalve against dirt and moisture. Do not mountanything onto the valve other than the standardvalve cap or other valve caps approved byMercedes-Benz for your vehicle. Do not use anyother valve caps or systems, e.g. tire pressuremonitoring systems.
Regularly check the pressure of all the tires par-ticularly prior to long trips. Adjust the tire pres-sure as necessary (Ypage 333).
The service life of tires depends, among otherthings, on the following factors:
RDriving style
RTire pressure
RDistance covered
Notes on tire tread
GWARNING
Insufficient tire tread will reduce tire traction.
The tire is no longer able to dissipate water.
This means that on wet road surfaces, the risk
of hydroplaning increases, in particular where
speed is not adapted to suit the driving con-
ditions. There is a risk of accident.
If the tire pressure is too high or too low, tires
may exhibit different levels of wear at differ-
ent locations on the tire tread. Thus, you
should regularly check the tread depth and
the condition of the tread across the entire
width of all tires.
Minimum tire tread depth for:
RSummer tires:

MOExtended tires (tires with run-flat
properties)
With MOExtended tires (tires with run flat char-acteristics), you can continue to drive your vehi-cle even if there is a total loss of pressure in oneor more tires.
MOExtended tires may only be used in conjunc-tion with an active tire pressure loss warningsystem or with an active tire pressure monitorand on wheels specifically tested by Mercedes-Benz.
Notes on driving with MOExtended tires with aflat tire (Ypage 315).
Vehicles equipped with MOExtended tires arenot equipped with a TIREFIT kit at the factory. Itis therefore recommended that you additionallyequip your vehicle with a TIREFIT kit if you mounttires that do not feature run-flat properties, e.g.winter tires. A TIREFIT kit can be obtained froma qualified specialist workshop.
Winter operation
General notes
Have your vehicle winter-proofed at a qualifiedspecialist workshop at the onset of winter.
Observe the notes in the "Changing a wheel"section (Ypage 350).
Driving with summer tires
At temperatures below 45 ‡ (+7 †), summertires lose elasticity and therefore traction andbraking power. Change the tires on your vehicleto M+S tires. Using summer tires at very coldtemperatures could cause cracks to form,thereby damaging the tires permanently.Mercedes-Benz cannot accept responsibility forthis type of damage.
GWARNING
Damaged tires can cause tire inflation pres-
sure loss. As a result, you could lose control of
your vehicle. There is a risk of accident.
Check the tires regularly for signs of damage
and replace any damaged tires immediately.
M+S tires
GWARNING
M+S tires with a tire tread depth of less than

For safety reasons, Mercedes-Benz recom-mends that you only use snow chains that havebeen specially approved for your vehicle byMercedes-Benz, or are of a correspondingstandard of quality. For more information,please contact a qualified specialist workshop.
If you intend to mount snow chains, please bearthe following points in mind:
RSnow chains may not be mounted on allwheel/tire combinations. Observe the infor-mation regarding permitted wheel/tire com-binations (Ypage 354).
ROnly use snow chains when driving on roadscompletely covered by snow. Remove thesnow chains as soon as possible when youcome to a road that is not snow-covered.
RLocal regulations may restrict the use of snowchains. Observe the appropriate regulations ifyou wish to mount snow chains.
RDo not exceed the maximum permissiblespeed of 31 mph (50 km/h).
ROn vehicles with AIR BODY CONTROL, youmust only drive at raised vehicle level if snowchains have been installed (Ypage 172).
RWhen snow chains are installed, never useActive Parking Assist (Ypage 175).
You may wish to deactivate ESP®when pullingaway with snow chains installed:
RAll vehicles (except Mercedes‑AMG vehicles)(Ypage 69)
RMercedes‑AMG vehicles (Ypage 70)
You can thereby allow the wheels to spin in acontrolled manner, achieving an increased driv-ing force (cutting action).
Tire pressure
Tire pressure specifications
Important safety notes
GWARNING
Underinflated or overinflated tires pose the
following risks:
Rthe tires may burst, especially as the load
and vehicle speed increase.
Rthe tires may wear excessively and/or
unevenly, which may greatly impair tire
traction.
Rthe driving characteristics, as well as steer-
ing and braking, may be greatly impaired.
There is a risk of an accident.
Follow recommended tire inflation pressures
and check the pressure of all the tires includ-
ing the spare wheel:
Rmonthly, at least
Rif the load changes
Rbefore beginning a long journey
Runder different operating conditions, e.g.
off-road driving
If necessary, correct the tire pressure.
The data on the Tire and Loading Informationplacard and tire pressure table shown here areexamples. Tire pressure specifications are vehi-cle-specific and may deviate from the datashown here. The tire pressure specificationsthat are valid for your vehicle can be found onthe Tire and Loading Information placard andtire pressure table on the vehicle.
General notes
The recommended tire pressures for the tiresmounted at the factory can be found on thelabels described here.
Operation with a trailer:the applicable valuefor the rear axle is the maximum tire pressurevalue stated in the table inside the fuel filler flap.
Further information on tire pressures can beobtained at a qualified specialist workshop.
Tire pressure333
Wheels and tires
Z

Tire and Loading Information placard
CRecommended tire pressures
The Tire and Loading Information placard is onthe B-pillar on the driver's side (Ypage 340).
The Tire and Loading Information placard con-tains the recommended tire pressures for coldtires. The recommended tire pressures are validfor the maximum permissible load and up to themaximum permissible vehicle speed.
Tire pressure table
The tire pressure table is on the inside of the fuelfiller flap. It shows the tire pressure for all tirespermitted at the factory for this vehicle; seeillustration (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 tirepressure information following is only valid forthat tire size. If a speed range precedes the tirepressure, the following tire pressure dataapplies to only this speed range.
The load conditions "partially laden" and "fullyladen" are defined in the table for different num-
bers of occupants and amounts of luggage. Theactual number of seats may differ.
Some tire pressure tables show only the rimdiameters instead of the full tire size, e.g.R18.Rim diameter is part of the tire size and can befound on the tire sidewall (Ypage 345).
If the tire pressures have been set to the lowervalues for lighter loads and/or lower roadspeeds, the pressures should be reset to thehigher values:
Rif you want to drive with an increased loadand/or
Rif you want to drive at higher road speeds
The tire pressures for increased loads and/orhigher road speeds, shown in the tire pressuretable, may have a negative effect on drivingcomfort.
If the tire pressure is not set correctly, this canlead to an excessive build up of heat and a sud-den loss of pressure.
For more information, contact a qualified spe-cialist workshop.
Important notes on tire pressure
GWARNING
If the tire pressure drops repeatedly, the
wheel, valve or tire may be damaged. Tire
pressure that is too low may result in a tire
blow-out. There is a risk of an accident.
RCheck the tire for foreign objects.
RCheck whether the wheel is losing air or the
valve is leaking.
If you are unable to rectify the damage, con-
tact a qualified specialist workshop.
334Tire pressure
Wheels and tires

GWARNING
If you fit unsuitable accessories onto tire
valves, the tire valves may be overloaded and
malfunction, which can cause tire pressure
loss. Due to their design, retrofitted tire pres-
sure monitors keep the tire valve open. This
can also result in tire pressure loss. There is a
risk of an accident.
Only screw the standard valve cap or other
valve caps approved by Mercedes-Benz for
your vehicle onto the tire valve.
Use a suitable pressure gauge to check the tirepressure. The outer appearance of a tire doesnot permit any reliable conclusion about the tirepressure. On vehicles equipped with the elec-tronic tire pressure monitor, the tire pressurecan be checked in the on-board computer.
The tire temperature and pressure increasewhen the vehicle is in motion. This is dependenton the driving speed and the load.
Therefore, you should only correct tire pres-sures when the tires are cold.
The tires are cold:
Rif the vehicle has been parked with the tiresout of direct sunlight for at least three hoursand
Rif the vehicle has not been driven further than1 mile (1.6 km)
The tire temperature changes depending on theoutside temperature, the vehicle speed and thetire load. If the tire temperature changes by18 ‡ (10 †), the tire pressure changes byapproximately 10 kPa (0.1 bar/1.5 psi). Takethis into account when checking the pressure ofwarm tires. Only correct the tire pressure if it istoo low for the current operating conditions. Ifyou check the tire pressure when the tires arewarm, the resulting value will be higher than ifthe tires were cold. This is normal. Do notreduce the tire pressure to the value specifiedfor cold tires. The tire pressure would otherwisebe too low.
Observe the recommended tire pressures forcold tires:
Ron the Tire and Loading Information placardon the B-pillar on the driver's side
Rin the tire pressure table on the fuel filler flap(Ypage 333)
Underinflated or overinflated tires
Underinflated tires
GWARNING
Tires with pressure that is too low can over-
heat and burst as a consequence. In addition,
they also suffer from excessive and/or irreg-
ular wear, which can severely impair the brak-
ing properties and the driving characteristics.
There is a risk of an accident.
Avoid tire pressures that are too low in all the
tires, including the spare wheel.
Underinflated tires may:
Roverheat, leading to tire defects
Radversely affect handling
Rwear excessively and/or unevenly
Rhave an adverse effect on fuel consumption
Overinflated tires
GWARNING
Tires with excessively high pressure can burst
because they are damaged more easily by
road debris, potholes etc. In addition, they
also suffer from irregular wear, which can
severely impair the braking properties and the
driving characteristics. There is a risk of an
accident.
Avoid tire pressures that are too high in all the
tires, including the spare wheel.
Overinflated tires may:
Rincrease the braking distance
Radversely affect handling
Rwear excessively and/or unevenly
Rhave an adverse effect on ride comfort
Rbe more susceptible to damage
Tire pressure335
Wheels and tires
Z

Maximum tire pressures
CExample: maximum permissible tire pres-sure
Never exceed the maximum permissible tireinflation pressure. Always observe the recom-mended tire pressure for your vehicle whenadjusting the tire pressure (Ypage 333).
iThe actual values for tires are vehicle-spe-cific and may deviate from the values in theillustration.
Checking the tire pressures
Important safety notes
Observe the notes on tire pressure(Ypage 333).
Information on air pressure for the tires on yourvehicle can be found:
Ron the vehicle's Tire and Loading Informationplacard on the B-pillar
Rin the tire pressure table in the fuel filler flap(Ypage 333)
Rin the "Tire pressure" section
Checking tire pressures manually
To determine and set the correct tire pressure,proceed as follows:
XRemove the valve cap of the tire that is to bechecked.
XPress the tire pressure gauge securely ontothe valve.
XRead the tire pressure and compare it to therecommended value on the Tire and LoadingInformation placard or the tire pressure table(Ypage 333).
XIf the tire pressure is too low, increase the tirepressure to the recommended value.
XIf the tire pressure is too high, release air. Todo so, press down the metal pin in the valve,using the tip of a pen for example. Then checkthe tire pressure again using the tire pressurechecker.
XScrew the valve cap onto the valve.
XRepeat these steps for the other tires.
Tire pressure loss warning system
General notes
While the vehicle is in motion, the tire pressureloss warning system monitors the set tire pres-sure using the rotational speed of the wheels.This enables the system to detect significantpressure loss in a tire. If the speed of rotation ofa wheel changes as a result of a loss of pressure,a corresponding warning message will appear inthe multifunction display.
You can recognize the tire pressure loss warningby theRun Flat Indicator ActiveRun Flat Indicator ActivePressPress'OK' to Restart'OK' to Restartmessage which appears intheServiceServicemenu of the multifunction display.Information on the message display can befound in the "Restarting the tire pressure losswarning system" section (Ypage 337).
Important safety notes
The tire pressure warning system does not warnyou of an incorrectly set tire pressure. Observethe notes on the recommended tire pressure(Ypage 333).
The tire pressure loss warning does not replacethe need to regularly check the tire pressure. Aneven loss of pressure on several tires at thesame time cannot be detected by the tire pres-sure loss warning system.
The tire pressure monitor is not able to warn youof a sudden loss of pressure, e.g. if the tire ispenetrated by a foreign object. In the event of asudden loss of pressure, bring the vehicle to ahalt by braking carefully. Avoid abrupt steeringmovements.
The function of the tire pressure loss warningsystem is limited or delayed if:
Rsnow chains are mounted on your vehicle'stires.
Rroad conditions are wintry.
336Tire pressure
Wheels and tires

Ryou are driving on sand or gravel.
Ryou adopt a very sporty driving style (corner-ing at high speeds or driving with high rates ofacceleration).
Ryou are towing a very heavy or large trailer.
Ryou 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 ifyou have:
Rchanged the tire pressure
Rchanged the wheels or tires
Rmounted new wheels or tires
XBefore restarting, make sure that the tirepressures are set properly on all four tires forthe respective operating conditions.
The recommended tire pressure can be foundon the Tire and Loading Information placardon the B-pillar. Additionally, a tire pressuretable is attached to the fuel filler flap. The tirepressure loss warning system can only givereliable warnings if you have set the correcttire pressure. If an incorrect tire pressure isset, these incorrect values will be monitored.
XAlso observe the notes in the section on tirepressures (Ypage 333).
XMake sure that the SmartKey is in positionHin the ignition lock (Ypage 131).
XPress

Information on the message display can befound in the "Checking the tire pressure elec-tronically" section (Ypage 339).
Important safety notes
GWARNING
Each tire, including the spare (if provided),
should be checked at least once every two
weeks when cold and inflated to the pressure
recommended by the vehicle manufacturer
on the Tire and Loading Information placard
on the driver's door B-pillar or the tire pres-
sure label on the inside of the fuel filler flap. If
your vehicle has tires of a different size than
the size indicated on the Tire and Loading
Information placard or, if available, the tire
pressure label, you should determine the
proper tire pressure for those tires.
As an added safety feature, your vehicle has
been equipped with a tire pressure monitoring
system (TPMS) that illuminates a low tire pres-
sure telltale when one or more of your tires
are significantly underinflated. Accordingly,
when the low tire pressure telltale lights up,
you should stop and check your tires as soon
as 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 with
the 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 telltale 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 tirepressure to that recommended for cold tireswhich is suitable for the operating situation(Ypage 333). Note that the correct tire pressurefor the current operating situation must first betaught-in to the tire pressure monitor. If a sub-stantial loss of pressure occurs, the warningthreshold for the warning message is aligned tothe taught-in reference values. Restart the tirepressure monitor after adjusting the pressure ofthe cold tires (Ypage 339). The current pres-sures are saved as new reference values. As aresult, a warning message will appear if the tirepressure drops significantly.
The tire pressure monitor does not warn you ofan incorrectly set tire pressure. Observe thenotes on the recommended tire pressure(Ypage 333).
The tire pressure monitor is not able to warn youof a sudden loss of pressure, e.g. if the tire ispenetrated by a foreign object. In the event of asudden loss of pressure, bring the vehicle to ahalt by braking carefully. Avoid abrupt steeringmovements.
The tire pressure monitor has a yellow warninglamp in the instrument cluster for indicatingpressure loss or a malfunction. Whether thewarning lamp flashes or lights up indicateswhether a tire pressure is too low or the tirepressure monitor is malfunctioning:
Rif the warning lamp is lit continuously, the tirepressure on one or more tires is significantly
338Tire pressure
Wheels and tires

too low. The tire pressure monitor is not mal-functioning.
Rif the warning lamp flashes for around aminute and then remains lit constantly, thetire pressure monitor is malfunctioning.
In addition to the warning lamp, a messageappears in the multifunction display. Observethe information on display messages(Ypage 250).
It may take up to ten minutes for a malfunctionof the tire pressure monitor to be indicated. Amalfunction will be indicated by the tire pres-sure warning lamp flashing for approximatelyone minute and then remaining lit. When themalfunction has been rectified, the tire pressurewarning lamp goes out after a few minutes ofdriving.
The tire pressure values indicated by the on-board computer may differ from those meas-ured at a gas station with a pressure gauge. Thetire pressures shown by the on-board computerrefer to those measured at sea level. At highaltitudes, the tire pressure values indicated by apressure gauge are higher than those shown bythe on-board computer. In this case, do notreduce the tire pressures.
The operation of the tire pressure monitor canbe affected by interference from radio transmit-ting equipment (e.g. radio headphones, two-wayradios) that may be being operated in or near thevehicle.
Checking the tire pressure electroni-
cally
XMake sure that the SmartKey is in positionH(Ypage 131) in the ignition lock.
XPress

iThe actual values for tires are vehicle-spe-cific and may deviate from the values in theillustration.
Treadwear
The treadwear grade is a comparative ratingbased on the wear rate of the tire when testedunder controlled conditions on a specified U.S.government course. For example, a tire graded150 would wear one and one-half times as wellon the government course as a tire graded 100.
The relative performance of tires depends uponthe actual conditions of their use, however, andmay depart significantly from the norm due tovariations in driving habits, service practicesand differences in road characteristics and cli-mate.
Traction
GWARNING
The traction grade assigned to this tire is
based on straight-ahead braking traction
tests, and does not include acceleration, cor-
nering, hydroplaning, or peak traction char-
acteristics.
!Avoid wheelspin. This can lead to damage tothe drive train.
The traction grades – from highest to lowest –are AA, A, B and C. Those grades represent thetire's ability to stop on wet pavement as meas-ured under controlled conditions on specifiedgovernment test surfaces of asphalt and con-crete. A tire marked C may have poor tractionperformance.
The safe speed on a wet, snow covered or icyroad is always lower than on dry road surfaces.
You should pay special attention to road condi-tions when temperatures are around freezingpoint.
Mercedes-Benz recommends a minimum treaddepth of