run flat MERCEDES-BENZ GLA 2019 Owners Manual

MOExtended tires .......................... 306
Optional equipment weight (defi-
nition) ............................................ 325
PSI (pounds per square inch)
(definition) .....................................324
Replacing ....................................... 325
Service life ..................................... 305
Sidewall (definition) ....................... 325
Speed rating (definition) ................ 324
Storing ...........................................326
Structure and characteristics
(definition) ..................................... 323
Summer tires ................................. 306
Temperature .................................. 319
TIN (Tire Identification Number)
(definition) ..................................... 325
Tire bead (definition) ......................325
Tire pressure (definition) ................ 324
Tire pressures (recommended) ...... 324
Tire size (data) ............................... 329
Tire size designation, load-bear-
ing capacity, speed rating .............. 320
Tire tread ....................................... 305
Tire tread (definition) ..................... 325
Total load limit (definition) ............. 325
Traction ......................................... 319
Traction (definition) ....................... 325
Tread wear..................................... 319
Uniform Tire Quality Grading
Standards ...................................... 319
Uniform Tire Quality Grading
Standards (definition) .................... 323
Wear indicator (definition) ............. 325
Wheel rim (definition) .................... 324
see Flat tire
Tool
see Vehicle tool kit
Top Tether............................................ 56
Tow-starting
Emergency engine starting ............ 301
Important safety notes .................. 298
Installing the towing eye ................ 299
Removing the towing eye ............... 299
Towing
Permitted towing methods ............ 300
Towing a trailer
ESP®(Electronic Stability Pro-
gram) ............................................... 66
Towing away
Important safety guidelines ........... 298
Installing the towing eye ................ 299
Notes for 4MATIC vehicles ............ 301
Removing the towing eye ............... 299
Transporting the vehicle ................ 300
With both axles on the ground ....... 300
With the front axle raised ............... 299
Towing eye......................................... 287
Traction system
see ETS/4ETS (Electronic Trac-
tion System)
Traffic reports
see also Digital Operator's Man-
ual .................................................. 242
Transmission
see Automatic transmission
Transmission position display
(DIRECT SELECT lever)...................... 134
Transporting the vehicle.................. 300
Traveling uphill
Brow of hill ..................................... 156
Driving downhill ............................. 156
Maximum gradient-climbing
capability ....................................... 156
Trim pieces (cleaning instruc-
tions).................................................. 284
Trip computer (on-board com-
puter).................................................. 192
Trip odometer
Calling up ....................................... 192
Resetting (on-board computer) ...... 193
Trunk
Emergency release button ............... 83
Opening (from outside the vehi-
cle, HANDS-FREE ACCESS) .............. 80
Trunk lid
see Tailgate
Turn signals
Display message ............................ 214
Replacing bulbs (front) ................... 108
Switching on/off........................... 104
Two-way radio
Frequencies ................................... 332
Installation ..................................... 332
Transmission output (maximum) .... 332
Index21

Problems with the Occupant Classification System (OCS)
Be sure to observe the notes on "System self-test" (Ypage 50).
ProblemPossible causes/consequences andPPSolutions
The PASSENGER AIRBAG OFF indicator lamplights up and remainslit, even though thefront-passenger seat isoccupied by an adult ora person of a staturecorresponding to that ofan adult.
The classification of the person on the front-passenger seat is incor-rect.
XMake sure the conditions for a correct classification of the per-son on the front-passenger seat are met (Ypage 47).
XIf the PASSENGER AIR BAG OFF indicator lamp remains lit, thefront-passenger seat may not be used.
XHave OCS checked as soon as possible at an authorizedMercedes-Benz Center.
The PASSENGER AIRBAG OFF indicator lampdoes not light upand/or does not stayon.
The front-passengerseat is:
Runoccupied
Roccupied by theweight of a child upto twelve months oldin a child restraintsystem
OCS is malfunctioning.
XMake sure there is nothing between the seat cushion and thechild seat.
XMake sure that the entire base of the child restraint system restson the seat cushion of the front-passenger seat. The backrest ofthe forward-facing child restraint system must lie as flat as possi-ble against the backrest of the front passenger seat. If necessary,adjust the position of the front-passenger seat.
XMake sure that the seat cushion length is fully retracted.
XWhen installing the child restraint system, make sure that theseat belt is tight. Do not pull the seat belt tight using the front-passenger seat adjustment. This could result in the seat belt andthe child restraint system being pulled too tightly.
XCheck for correct installation of the child restraint system.
Make sure that the head restraint does not apply a load to thechild restraint system. If necessary, adjust the head restraintaccordingly.
XMake sure that no objects are applying additional weight onto theseat.
XIf the PASSENGER AIR BAG OFF indicator lamp remains offand/or the PASSENGER AIR BAG ON indicator lamp lights up, donot install a child restraint system on the front-passenger seat. Itis recommended that you install the child restraint system on asuitable rear seat.
XHave OCS checked as soon as possible at an authorizedMercedes-Benz Center.
Deployment of Emergency Tension-
ing Devices and air bags
Important safety notes
GWARNING
The air bag parts are hot after an air bag has
been deployed. There is a risk of injury.
Do not touch the air bag parts. Have a
deployed air bag replaced at a qualified spe-
cialist workshop as soon as possible.
GWARNING
A deployed air bag no longer offers any pro-
tection and cannot provide the intended pro-
Occupant safety51
Safety
Z

ProblemPossible causes/consequences andPPSolutions
The engine is not run-ning smoothly and ismisfiring.
There is a malfunction in the engine electronics or in a mechanicalcomponent of the engine management system.
XOnly depress the accelerator pedal slightly.Otherwise, non-combusted fuel may get into the catalytic con-verter and damage it.
XHave the cause rectified immediately at a qualified specialistworkshop.
The coolant tempera-ture gauge shows avalue above 248 ‡(120 †). The warninglamp may also be onand a warning tone maysound.
The coolant level is too low. The coolant is too hot and the engine isno longer being cooled sufficiently.
XStop as soon as possible and allow the engine and the coolant tocool down.
XCheck the coolant level (Ypage 276). Observe the warning notesas you do so and add coolant if necessary.
Notes on towing vehicles
The vehicle is not suitable for attaching towbar systems, such as those used for flat tow-ing or dinghy towing.
Attaching or using tow bar systems may resultin damage to the vehicle.
When towing a vehicle with tow bar systems,safe driving characteristics cannot be guaran-teed for the towing vehicle or the towed vehi-cle.
The vehicle/trailer combination may swerve.
Observe the permissible towing methods(Ypage 300) and the notes on towing withboth axles on the ground (Ypage 300).
DYNAMIC SELECT button (all vehi-
cles except Mercedes-AMG vehicles)
Use the DYNAMIC SELECT button to changethe drive program. Depending on the drive pro-gram selected the following vehicle character-istics will change:
Rthe drive (engine and transmission manage-ment)
Rthe sound of the exhaust system (vehicleswith sports exhaust system)
Rthe steering
Rthe availability of the ECO start/stop func-tion
Rthe climate control
Each time you start the engine with the Smart-Key or the Start/Stop button, drive programCis activated. For further information aboutstarting the engine, see (Ypage 126).
XPress DYNAMIC SELECT buttonCas manytimes as necessary until the desired driveprogram is selected.The selected drive program appears in themultifunction display. After five seconds, thedisplay goes out and the status symbol ofthe selected drive program appears.
In addition, the current drive program set-tings are displayed briefly in the multimediasystem display.
iIn a few countries, the ECO start/stopfunction is deactivated at the factory due tothe available fuel grade. In this case, theECO start/stop function is not available inany drive program, regardless of the displayin the multimedia system display.
132DYNAMIC SELECT button (all vehicles except Mercedes-AMG vehicles)
Driving and parking

Bear in mind that at a speed of only 30 mph(approximately 50 km/h), the vehicle covers adistance of 44 ft (approximately 14 m) persecond.
Drive sensibly – save fuel
Observe the following tips to save fuel:
RThe tires should always be inflated to therecommended tire pressure.
RRemove unnecessary loads.
RRemove roof racks when they are not nee-ded.
RWarm up the engine at low engine speeds.
RAvoid frequent acceleration or braking.
RHave all maintenance work carried out asindicated by the service intervals in theMaintenance Booklet or by the service inter-val display.
Fuel consumption also increases when drivingin cold weather, in stop-start traffic and in hillyterrain.
Drinking and driving
GWARNING
Drinking and driving and/or taking drugs
and driving are very dangerous combina-
tions. Even a small amount of alcohol or
drugs can affect your reflexes, perceptions
and judgment.
The possibility of a serious or even fatal
accident is greatly increased when you drink
or take drugs and drive.
Do not drink or take drugs and drive or allow
anyone to drive who has been drinking or
taking drugs.
Emission control
GDANGER
Combustion engines emit poisonous
exhaust gases such as carbon monoxide.
Inhaling these exhaust gases is hazardous to
health and can result in poisoning. There is a
risk of fatal injury. Therefore, never leave the
engine running an enclosed space without
adequate ventilation.
Certain engine systems are designed to keepthe level of poisonous components in exhaustfumes within legal limits.
These systems only work at peak efficiency ifthey are serviced exactly in accordance withthe manufacturer's specifications. Always havework on the engine carried out at a qualifiedspecialist workshop. Mercedes-Benz recom-mends that you use an authorized Mercedes-Benz Center for this purpose. In particular,work relevant to safety or on safety-relatedsystems must be carried out at a qualified spe-cialist workshop.
The engine settings must not be changedunder any circumstances. Furthermore, allspecific service work must be carried out atregular intervals and in accordance with theMercedes-Benz service requirements. Detailscan be found in the Maintenance Booklet.
ECO display
The ECO display shows you how economicalyour driving style is. The ECO display assistsyou in achieving the most economical drivingstyle for the selected settings and prevailingconditions. Your driving style can significantlyinfluence the vehicle's consumption.
CAcceleration
DCoasting

Tires
Display messagesPossible causes/consequences andPPSolutions
Check Tire Pres‐Check Tire Pres‐sure Soonsure SoonCanada only:
The tire pressure loss warning system has detected a significantloss in pressure.
A warning tone also sounds.
Possible causes:
Ryou have changed the positions of the wheels and tires or instal-led new wheels and tires
Rthe tire pressure in one or more tires has dropped
GWARNING
Tire pressures that are too low pose the following hazards:
Rthey may burst, especially as the load and vehicle speed increase.
Rthey may wear excessively and/or unevenly, which may greatlyimpair tire traction.
Rthe driving characteristics, as well as steering and braking, maybe greatly impaired.
There is a risk of an accident.
XStop the vehicle without making any sudden steering or brakingmaneuvers. Pay attention to the traffic conditions as you do so.
XSecure the vehicle against rolling away (Ypage 145).
XCheck the tires and, if necessary, follow the instructions for a flattire (Ypage 287).
XCheck the tire pressures and, if necessary, correct the tire pres-sure.
XRestart the tire pressure loss warning system when the tire pres-sure is correct (Ypage 311).
Check Tire Pres‐Check Tire Pres‐sure Then Restartsure Then RestartRun Flat IndicatorRun Flat Indicator
Canada only:
The tire pressure loss warning system generated a display messageand has not been restarted since.
XSet the correct tire pressure in all four tires.
XRestart the tire pressure loss warning system (Ypage 311).
Run Flat IndicatorRun Flat IndicatorInoperativeInoperativeCanada only:
The tire pressure loss warning system is faulty.
XVisit a qualified specialist workshop.
Please CorrectPlease CorrectTire PressureTire PressureUSA only:
The tire pressure is too low in at least one of the tires, or the tirepressure difference between the wheels is too great.
XCheck the tire pressures at the next opportunity (Ypage 311).
XIf necessary, correct the tire pressure.
XRestart the tire pressure monitor (Ypage 314).
Displaymessages223
On-b oard computer and displays
Z

XSwitch off the engine.
XVehicles without KEYLESS-GO:removethe SmartKey from the ignition lock.
XVehicles with KEYLESS-GO start-func-tion or KEYLESS-GO:open the driver'sdoor.The vehicle electronics are now in positionZ. This is the same as the SmartKey havingbeen removed.
XVehicles with KEYLESS-GO start-func-tion or KEYLESS-GO:remove the Start/Stop button from the ignition lock(Ypage 125).
XMake sure that the engine cannot be startedvia your smartphone (Ypage 126).
XMake sure that the passengers are notendangered as they do so. Make sure thatno one is near the danger area while awheel is being changed. Anyone who is notdirectly assisting in the wheel changeshould, for example, stand behind the bar-rier.
XGet out of the vehicle. Pay attention to traf-fic conditions when doing so.
XClose the driver's door.
MOExtended tires (tires with run-flat
properties)
General notes
With MOExtended tires (tires with run flatcharacteristics), you can continue to drive yourvehicle even if there is a total loss of pressurein one or more tires. The affected tire must notshow any clearly visible damage.
You can recognize an MOExtended tire by theMOExtended marking which appears on thesidewall of the tire. You will find this markingnext to the tire size designation, the load-bear-ing capacity and the speed index(Ypage 320).
MOExtended tires may be used only in con-junction with an activated tire pressure losswarning system (Canada only) or tire pressuremonitor (USA only).
If a pressure loss warning messageappears in the multifunction display:
Robserve the instructions in the display mes-sages (Ypage 223).
Rcheck the tire for damage
Rif driving on, observe the following notes
The driving distance possible in run-flat modeis approximately 50 miles (80 km) when thevehicle is partially laden. When the vehicle isfully laden it is approximately 19 miles(30 km).
In addition to the vehicle load, the driving dis-tance possible depends upon:
RVehicle speed
RRoad condition
ROutside temperature
The driving distance possible in run-flat modemay be reduced by extreme driving conditionsor maneuvers, or it can be increased through amoderate style of driving.
The driving distance possible in run-flat modeis counted from the moment the tire pressureloss warning appears in the multifunction dis-play.
You must not exceed the maximum permissi-ble speed for limp-home mode of 50 mph(80 km/h).
When replacing one or all tires, please observethe following specifications for your vehicle'stires:
RSize
RType and
RThe "MOExtended" marking
If a tire has gone flat and cannot be replacedwith an MOExtended tire, a standard tire maybe used as a temporary measure. Make surethat you use the proper size and type (summeror winter tire).
Vehicles equipped with MOExtended tires arenot equipped with a TIREFIT kit at the factory.It is therefore recommended that you addition-ally equip your vehicle with a TIREFIT kit if youmount tires that do not feature run-flat charac-teristics, e.g. winter tires. A TIREFIT kit may beobtained from a qualified specialist workshop.
288Flat tire
Roadside Assistance

Important safety notes
GWARNING
If you install wheels and tires with incorrect
dimensions, the service brake or wheel sus-
pension components may be damaged.
There is a risk of an accident.
Always replace wheels and tires with ones
that comply with the specifications of the
original part.
When replacing wheels, pay attention to the:
RDesignation
RModel
When replacing tires, pay attention to the:
RDesignation
RManufacturer
RModel
GWARNING
A flat tire will severely affect the driving
characteristics as well as the steering and
braking of the vehicle. There is a risk of an
accident.
Tires without run-flat characteristics:
RDo not drive on with a flat tire.
RChange the flat tire immediately with an
emergency spare wheel or spare wheel.
Alternatively, consult a qualified specialist
workshop.
Tires with run-flat characteristics:
RObserve the information and warning
notes on MOExtended tires (run-flat tires).
Accessories that are not approved for yourvehicle by Mercedes-Benz or are not beingused correctly can impair the operating safety.
Before purchasing and using non-approvedaccessories, visit a qualified specialist work-shop and inquire about:
Rsuitability
Rlegal stipulations
Rfactory recommendations
Further information regarding wheels and tirescan be found under "Wheel/tire combinations"(Ypage 329).
You can ask for information regarding permit-ted wheel/tire combinations at an authorizedMercedes-Benz Center.
Information on tire pressure can be found:
Ron the Tire and Loading Information placardon the B-pillar on the driver's side(Ypage 316)
Rin the tire pressure table in the fuel filler flap(Ypage 144)
Runder "Tire pressure" (Ypage 307)
Operation
Information on driving
Check the tire pressure when the vehicle isheavily laden and adjust prior to a trip.
While driving, pay attention to vibrations,noises and unusual handling characteristics,e.g. pulling to one side. This may indicate thatthe wheels or tires are damaged. If you sus-pect that a tire is defective, reduce your speedimmediately. Stop the vehicle as soon as pos-sible to check the wheels and tires for dam-age. Hidden tire damage could also be causingthe unusual handling characteristics. If youfind no signs of damage, have the tires andwheels checked at a qualified specialist work-shop.
When parking your vehicle, make sure that thetires do not get deformed by the curb or otherobstacles. If they cannot be avoided, driveover obstacles such as curbs slowly and at anobtuse angle. Otherwise, you may damage thewheels or tires.
Regular checking of wheels and tires
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 dam-
age and replace any damaged tires immedi-
ately.
304Operation
Wheels and ti res

(tires with run-flat characteristics)" section(Ypage 288).
ROnly mount tires of the correct size onto thewheels.
RBreak in new tires at moderate speeds forthe first 60 miles (100 km). The new tiresonly reach their full performance after thisdistance.
RDo not drive with tires which have too littletread depth. This significantly reduces thetraction on wet roads (hydroplaning).
RReplace the tires after six years at the lat-est, regardless of wear.
Observe the notes on the emergency sparewheel (Ypage 330).
MOExtended tires (tires with run-flat
properties)
With MOExtended tires (tires with run flatcharacteristics), you can continue to drive yourvehicle even if there is a total loss of pressurein one or more tires.
MOExtended tires may only be used in con-junction with an activated tire pressure losswarning system (Canada only) or tire pressuremonitor (USA only) and only on wheels specifi-cally tested by Mercedes-Benz.
Notes on driving with MOExtended tires with aflat tire (Ypage 288).
Vehicles equipped with MOExtended tires arenot equipped with a TIREFIT kit at the factory.It is therefore recommended that you addition-ally equip your vehicle with a TIREFIT kit if youmount tires that do not feature run-flat charac-teristics, e.g. winter tires. A TIREFIT kit may beobtained from a 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 325).
Driving with summer tires
At temperatures below 45 ‡ (+7 †), summertires lose elasticity and therefore traction andbraking power. Change the tires on your vehi-cle to M+S tires. Using summer tires at verycold temperatures could cause cracks to form,thereby damaging the tires permanently.Mercedes-Benz cannot accept responsibilityfor this 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 dam-
age and replace any damaged tires immedi-
ately.
M+S tires
GWARNING
M+S tires with a tire tread depth of less than

When you have mounted the M+S tires:
XCheck the tire pressures (Ypage 307).
XRestart the tire pressure monitor (USA only)(Ypage 314).
XRestart the tire pressure loss warning sys-tem (Canada) (Ypage 311)
Snow chains
GWARNING
If snow chains are mounted on the rear
wheels, the snow chains could cause abra-
sion to the vehicle body or to chassis com-
ponents. This could cause damage to the
vehicle or the tires. There is a risk of an
accident.
To avoid hazardous situations:
Rnever mount snow chains on the rear
wheels
Ronly mount snow chains in pairs on the
front wheels.
!On some tire sizes there is not enoughspace for snow chains. To avoid damage tothe vehicle or tires, observe the "Wheel andtire combinations" section under "Tires andwheels".
For safety reasons, Mercedes-Benz recom-mends that you only use snow chains thathave been specially approved for your vehicleby Mercedes-Benz, or are of a correspondingstandard of quality. For more information,please contact a qualified specialist workshop.
If you intend to mount snow chains, pleasebear the following points in mind:
RSnow chains may not be mounted on allwheel/tire combinations. Permissiblewheel-tire combinations (Ypage 329).
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 ofsnow chains. Observe the appropriate regu-lations if you wish to mount snow chains.
RDo not exceed the maximum permissiblespeed of 30mph (50 km/h).
RIf snow chains are installed, you cannot useActive Parking Assist (Ypage 176).
You may wish to deactivate ESP®when pullingaway with snow chains installed . This allowsthe wheels to spin in a controlled manner, ach-ieving increased propulsive force (cuttingaction).
RDeactivate ESP®(all vehicles exceptMercedes-AMG vehicles) (Ypage 64)
RDeactivate ESP®(Mercedes-AMG vehicles)(Ypage 65)
Information about driving with an emergencyspare wheel (Ypage 330).
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
steering 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
including 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.
iThe data on the Tire and Loading Informa-tion placard and tire pressure table shownhere are examples. Tire pressure specifica-
Tire pressure307
Wheels and tires
Z

rotation of a wheel changes as a result of aloss of pressure, a corresponding warningmessage will appear in the multifunction dis-play.
You can recognize the tire pressure loss warn-ing by theRun Flat Indicator ActiveRun Flat Indicator ActivePress 'OK' to RestartPress 'OK' to Restartmessage in the mul-tifunction display in theServ.Serv.menu. Informa-tion on the message display can be found inthe "Restarting the tire pressure loss warning"section (Ypage 311).
Important safety notes
The tire pressure warning system does notwarn you of an incorrectly set tire pressure.Observe the notes on the recommended tirepressure (Ypage 307).
The tire pressure loss warning does notreplace the need to regularly check the tirepressure. An even loss of pressure on severaltires at the same time cannot be detected bythe tire pressure loss warning system.
The tire pressure monitor is not able to warnyou of a sudden loss of pressure, e.g. if thetire is penetrated by a foreign object. In theevent of a sudden loss of pressure, bring thevehicle to a halt by braking carefully. Avoidabrupt steering movements.
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.
Ryou are driving on sand or gravel.
Ryou adopt a very sporty driving style (corner-ing at high speeds or driving with high ratesof acceleration).
Ryou are driving with a heavy load (in thevehicle or on the roof)
Restarting the tire pressure loss warn-
ing system
Restart the tire pressure loss warning systemif you 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 tiresfor the respective operating conditions.
The recommended tire pressure can befound on the Tire and Loading Informationplacard on the B-pillar. Additionally, a tirepressure table is attached to the fuel fillerflap. The tire pressure loss warning systemcan only give reliable warnings if you haveset the correct tire pressure. If an incorrecttire pressure is set, these incorrect valueswill be monitored.
XAlso observe the notes in the section on tirepressures (Ypage 307).
XMake sure that the SmartKey is in positionHin the ignition lock (Ypage 125).
XPressYoreon the steering wheelto select theServ.Serv.menu.
XPress thecordbutton to selectTire PressureTire Pressure.
XPress thevbutton.TheRun Flat Indicator Active PressRun Flat Indicator Active Press'OK' to Restart'OK' to Restartmessage appears in themultifunction display.
If you wish to confirm the restart:
XPress thevbutton.TheTire Pressure Now OK?Tire Pressure Now OK?messageappears in the multifunction display.
XPress thecordbutton to selectYesYes.
XPress thevbutton.TheRun Flat Indicator RestartedRun Flat Indicator Restartedmes-sage appears in the multifunction display.
After a teach-in period, the tire pressureloss warning system will monitor the set tirepressures of all four tires.
If you wish to cancel the restart:
XPress the8button.
or
XIf theTire Pressure Now OK?Tire Pressure Now OK?messageappears, press thecordbutton toselectCancelCancel.
XPress thevbutton.The tire pressure values stored at the lastrestart will continue to be monitored.
Tire pressure monitor (Canada only)
General notes
If a tire pressure monitor is installed, the vehi-cle's wheels have sensors that monitor the tirepressures in all four tires. The tire pressure
Tire pressure311
Wheels and tires
Z