
(B) Tire Ply Material:The type of cord andnumber of plies in the sidewall and under thetread.
(C) Tire Identification Number (TIN):The TireIdentification Number (TIN). The TIN showsthe manufacturer and plant code, tire size, anddate the tire was manufactured. The TIN is moldedonto both sides of the tire, although only oneside may have the date of manufacture.
(D) Maximum Cold Inflation LoadLimit:Maximum load that can be carried and themaximum pressure needed to support thatload. SeeInflation - Tire Pressure on page 6-54andLoading the Vehicle on page 5-18.
(E) Tire Inflation:The temporary use tire orcompact spare tire should be inflated to 60 psi(420 kPa). For more information on tire pressureand inflation seeInflation - Tire Pressure onpage 6-54andSpare Tire on page 6-90.
(F) Tire Size:A combination of letters andnumbers define a tire’s width, height, aspect ratio,construction type and service description. Theletter T as the first character in the tire size meansthe tire is for temporary use only.
(G) TPC Spec (Tire Performance CriteriaSpecification):Original equipment tires designedto GM’s specific tire performance criteria havea TPC specification code molded onto the sidewall.GM’s TPC specifications meet or exceed allfederal safety guidelines.
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(A) Tire Size:The tire size code is a combinationof letters and numbers used to define a particulartire’s width, height, aspect ratio, constructiontype and service description. See the “Tire Size”illustration later in this section for more detail.
(B) TPC Spec (Tire Performance CriteriaSpecification):Original equipment tires designedto GM’s specific tire performance criteria havea TPC specification code molded onto the sidewall.GM’s TPC specifications meet or exceed allfederal safety guidelines.
(C) Dual Tire Maximum Load:Maximum loadthat can be carried and the maximum pressureneeded to support that load when used in a dualconfiguration.
(D) DOT (Department of Transportation):TheDepartment of Transportation (DOT) codeindicates that the tire is in compliance with theU.S. Department of Transportation Motor VehicleSafety Standards.
(E) Tire Identification Number (TIN):The lettersand numbers following DOT code are the TireIdentification Number (TIN). The TIN showsthe manufacturer and plant code, tire size, anddate the tire was manufactured. The TIN is moldedonto both sides of the tire, although only oneside may have the date of manufacture.
Light Truck Tire Example
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Treadwear Indicators:Narrow bands, sometimescalled wear bars, that show across the tread ofa tire when only 1/16 inch (1.6 mm) of treadremains. SeeWhen It Is Time for New Tires onpage 6-64.
UTQGS (Uniform Tire Quality GradingStandards):A tire information system thatprovides consumers with ratings for a tire’straction, temperature, and treadwear. Ratings aredetermined by tire manufacturers usinggovernment testing procedures. The ratings aremolded into the sidewall of the tire. SeeUniformTire Quality Grading on page 6-67.
Vehicle Capacity Weight:The number ofdesignated seating positions multiplied by 150 lbs(68 kg) plus the rated cargo load. SeeLoadingthe Vehicle on page 5-18.
Vehicle Maximum Load on the Tire:Load on anindividual tire due to curb weight, accessoryweight, occupant weight, and cargo weight.
Vehicle Placard:A label permanently attached toa vehicle showing the vehicle’s capacity weightand the original equipment tire size andrecommended inflation pressure. See “Tire andLoading Information Label” underLoadingthe Vehicle on page 5-18.
Inflation - Tire Pressure
Tires need the correct amount of air pressure tooperate effectively.
Notice:Do not let anyone tell you thatunder-inflation or over-inflation is all right. It isnot. If your tires do not have enough air(under-inflation), you can get the following:
•Too much flexing
•Too much heat
•Tire overloading
•Premature or irregular wear
•Poor handling
•Reduced fuel economy
If your tires have too much air (over-inflation),you can get the following:
•Unusual wear
•Poor handling
•Rough ride
•Needless damage from road hazards
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A Tire and Loading Information label is attached tothe vehicle’s center pillar. This label lists yourvehicle’s original equipment tires and shows thecorrect inflation pressures for your tires when theyare cold. The recommended cold tire inflationpressure, shown on the label, is the minimumamount of air pressure needed to supportyour vehicle’s maximum load carrying capacity.
For additional information regarding how muchweight your vehicle can carry, and an example ofthe Tire and Loading Information label, seeLoading the Vehicle on page 5-18. How you loadyour vehicle affects the vehicle handling andride comfort, never load your vehicle with moreweight than it was designed to carry.
When to Check
Check your tires once a month or more. Do notforget to check the spare tire. If your vehicle has acompact spare tire, it should be at 60 psi (420 kPa).For additional information seeSpare Tire onpage 6-90.
How to Check
Use a good quality pocket-type gage to check tirepressure. You cannot tell if your tires areproperly inflated simply by looking at them. Radialtires may look properly inflated even when theyare under-inflated. Check the tire’s inflationpressure when the tires are cold. Cold means yourvehicle has been sitting for at least three hoursor driven no more than 1 mile (1.6 km).
Remove the valve cap from the tire valve stem.Press the tire gage firmly onto the valve toget a pressure measurement. If the cold tireinflation pressure matches the recommendedpressure on the Tire and Loading Informationlabel, no further adjustment is necessary. If theinflation pressure is low, add air until you reach therecommended amount.
If you overfill the tire, release air by pushing onthe metal stem in the center of the tire valve.Re-check the tire pressure with the tire gage.
Be sure to put the valve caps back on the valvestems. They help prevent leaks by keeping out dirtand moisture.
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Professional Vehicle
The proper inflation of the tires on yourprofessional vehicle depends on the type of tireson it.
•If your vehicle has P235/60R17 size tires, the
cold inflation pressure is 41 psi (284 kPa).
•If your vehicle has LT235/60R17E size tires,
the cold inflation pressure depends on thevehicle mass and should be determined by thevehicle coach-builder. A Tire and LoadingInformation label provided by the final stagemanufacturer should be attached to the B-pillaron the driver’s side of the vehicle. If the finalstage manufacturer’s label is not present,the coach-builder should be consulted. Do notuse the tire pressures indicated on theGeneral Motors label. These tire pressures arefor the incomplete vehicle and are not thecorrect tire pressures for the completedprofessional vehicle.
Operation at inflation pressures below thisrecommendation may cause your tires to becomeoverloaded.
High-Speed Operation
{WARNING:
Driving at high speeds, 160 km/h (100 mph) or
higher, puts an additional strain on tires. Sustained
high-speed driving causes excessive heat build up
and can cause sudden tire failure. You could have
a crash and you or others could be killed. Some
high-speed rated tires require inflation pressure
adjustment for high speed operation. When speed
limits and road conditions are such that a vehicle
can be driven at high speeds, make sure the tires
are rated for high speed operation, in excellent
condition, and set to the correct cold tire inflation
pressure for the vehicle load.
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If your vehicle has P235/55R17 or P245/50R18 sizetires, and you will be driving at speeds of 100 mph(160 km/h) or higher, where it is legal, set the coldinflation pressure to the maximum inflation pressureshown on the tire sidewall, or 38 psi (265 kPa),whichever is lower. See the example following.
Example:
You will find the maximum load and inflation pressuremolded on the tire’s sidewall, in small letters, nearthe rim flange. It will read something like this: Maximumload 690 kg (1521 lbs) 300 kPa (44 psi) Max. Press.
For this example, you would set the inflation pressure forhigh-speed driving at 38 psi (265 kPa).
When you end this high-speed driving, return the tires tothe cold inflation pressure shown on the Tire andLoading Information label. SeeLoading the Vehicle onpage 5-18.
Tire Pressure Monitor System
The Tire Pressure Monitor System (TPMS) uses radioand sensor technology to check tire pressure levels. TheTPMS sensors monitor the air pressure in yourvehicle’s tires and transmit tire pressure readings to areceiver located in the vehicle.
Each tire, including the spare (if provided), should bechecked monthly when cold and inflated to the inflationpressure recommended by the vehicle manufactureron the vehicle placard or tire inflation pressure label.(If your vehicle has tires of a different size than the sizeindicated on the vehicle placard or tire inflationpressure label, you should determine the proper tireinflation pressure for those tires.)
As an added safety feature, your vehicle has beenequipped with a tire pressure monitoring system (TPMS)that illuminates a low tire pressure telltale when oneor more of your tires is significantly under-inflated.
Accordingly, when the low tire pressure telltaleilluminates, you should stop and check your tires assoon as possible, and inflate them to the properpressure. Driving on a significantly under-inflated tirecauses the tire to overheat and can lead to tire failure.Under-inflation also reduces fuel efficiency and tiretread life, and may affect the vehicle’s handlingand stopping ability.
Please note that the TPMS is not a substitute for propertire maintenance, and it is the driver’s responsibility tomaintain correct tire pressure, even if under-inflation hasnot reached the level to trigger illumination of theTPMS low tire pressure telltale.
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Your vehicle has also been equipped with a TPMSmalfunction indicator to indicate when the system is notoperating properly. The TPMS malfunction indicatoris combined with the low tire pressure telltale. When thesystem detects a malfunction, the telltale will flash forapproximately one minute and then remain continuouslyilluminated. This sequence will continue uponsubsequent vehicle start-ups as long as themalfunction exists.
When the malfunction indicator is illuminated, thesystem may not be able to detect or signal low tirepressure as intended. TPMS malfunctions may occur fora variety of reasons, including the installation ofreplacement or alternate tires or wheels on the vehiclethat prevent the TPMS from functioning properly.Always check the TPMS malfunction telltale afterreplacing one or more tires or wheels on your vehicle toensure that the replacement or alternate tires andwheels allow the TPMS to continue to function properly.
SeeTire Pressure Monitor Operation on page 6-58for additional information.
Federal Communications Commission
(FCC) and Industry and Science
Canada
SeeRadio Frequency Statement on page 8-20forinformation regarding Part 15 of the FederalCommunications Commission (FCC) Rules andRSS-210/211 of Industry and Science Canada.
Tire Pressure Monitor Operation
This vehicle may have a Tire Pressure Monitor System(TPMS). The TPMS is designed to warn the driverwhen a low tire pressure condition exists. TPMS sensorsare mounted onto each tire and wheel assembly,excluding the spare tire and wheel assembly. The TPMSsensors monitor the air pressure in the vehicle’s tiresand transmits the tire pressure readings to a receiverlocated in the vehicle.
When a low tire pressurecondition is detected, theTPMS illuminates thelow tire pressure warninglight located on theinstrument panel cluster.
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At the same time a message to check the pressure in aspecific tire appears on the Driver Information Center(DIC) display. The low tire pressure warning lightand the DIC warning message come on at each ignitioncycle until the tires are inflated to the correct inflationpressure. Using the DIC, tire pressure levels canbe viewed by the driver. For additional information anddetails about the DIC operation and displays seeDIC Operation and Displays on page 4-62andDICWarnings and Messages on page 4-67.
The low tire pressure warning light may come on in coolweather when the vehicle is first started, and thenturn off as you start to drive. This could be an earlyindicator that the air pressure in the tire(s) are gettinglow and need to be inflated to the proper pressure.
A Tire and Loading Information label, attached to yourvehicle, shows the size of your vehicle’s originalequipment tires and the correct inflation pressure foryour vehicle’s tires when they are cold. SeeLoading theVehicle on page 5-18, for an example of the Tire andLoading Information label and its location on yourvehicle. Also seeInflation - Tire Pressure on page 6-54.
Your vehicle’s TPMS can warn you about a low tirepressure condition but it does not replace normaltire maintenance. SeeTire Inspection and Rotation onpage 6-62andTires on page 6-46.
Notice:Using non-approved tire sealants coulddamage the Tire Pressure Monitor System (TPMS)sensors. TPMS sensor damage caused by usingan incorrect tire sealant is not covered by thevehicle warranty. Always use the GM approved tiresealant available through your dealer/retailer.
Factory-installed Tire Inflator Kits use a GM approvedliquid tire sealant. Using non-approved tire sealantscould damage the TPMS sensors. SeeTire Sealant andCompressor Kit on page 6-71for information regardingthe inflator kit materials and instructions.
TPMS Malfunction Light and Message
The TPMS will not function properly if one or more of theTPMS sensors are missing or inoperable. When thesystem detects a malfunction, the low tire warning lightflashes for about one minute and then stays on forthe remainder of the ignition cycle. A DIC warningmessage is also displayed. The low tire warning lightand DIC warning message come on at each ignitioncycle until the problem is corrected. Some of theconditions that can cause the malfunction light and DICmessage to come on are:
•One of the road tires has been replaced with the
spare tire. The spare tire does not have a TPMSsensor. The TPMS malfunction light and DICmessage should go off once you re-install the roadtire containing the TPMS sensor.
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