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2023 - CRC - 5/4/22
Vehicle Care 429
tire fill alert feature is not
working, use a tire pressure
gauge.
TPMS Sensor Matching
Process—Auto Learn
Function
Each TPMS sensor has a
unique identification code. The
identification code needs to be
matched to a new tire/wheel
position after rotating the
tires or replacing one or more
of the TPMS sensors. When a
tire is installed, the vehicle
must be stationary for about
20 minutes before the system
recalculates. The following
relearn process takes up to
10 minutes, driving at a
minimum speed of 20 km/h
(12 mph). A dash (-) or pressure
value will display in the DIC.
See Driver Information Center
(DIC) (Base Level) 0129 or
Driver Information Center
(DIC) (Uplevel) 0132. A warning
message displays in the DIC if
a problem occurs during the
relearn process.
Tire Inspection
We recommend that the
tires, including the spare
tire, if the vehicle has one,
be inspected for signs of
wear or damage at least
once a month.
Replace the tire if:
.The indicators at three or
more places around the
tire can be seen.
.There is cord or fabric
showing through the
tire's rubber.
.The tread or sidewall is
cracked, cut, or snagged
deep enough to show
cord or fabric.
.The tire has a bump,
bulge, or split.
.The tire has a puncture,
cut, or other damage that
cannot be repaired well
because of the size or
location of the damage.
Tire Rotation
Tires should be rotated
according to the interval
specified in the
Maintenance Schedule. See
Maintenance Schedule
0 469.
Tires are rotated to
achieve a uniform wear for
all tires. The first rotation is
the most important.
Anytime unusual wear is
noticed, rotate the tires as
soon as possible, check for
proper tire inflation
pressure, and check for
damaged tires or wheels.
If the unusual wear
continues after the
rotation, check the wheel
alignment. See When It Is
Time for New Tires 0431
and
Wheel Replacement 0436.
Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
430 Vehicle Care
Use this rotation pattern if
the vehicle has different
size tires on the front
and rear.
Different tire sizes should
not be rotated front
to rear.Use this rotation pattern
when rotating tires of the
same size installed on all
four wheel positions.
Adjust the front and rear
tires to the recommended
inflation pressure on the
Tire and Loading
Information label after the
tires have been rotated.
See Tire Pressure0422
and
Vehicle Load Limits 0255. Reset the Tire Pressure
Monitor System. See Tire
Pressure Monitor
Operation
0425.
Check that all wheel nuts
are properly tightened. See
“Wheel Nut Torque” under
Capacities and
Specifications 0480.
{Warning
Rust or dirt on a wheel,
or on the parts to which it
is fastened, can cause
wheel nuts to become
loose over time. The
wheel could come off and
cause a crash. When
changing a wheel, remove
any rust or dirt from
places where the wheel
attaches to the vehicle. In
an emergency, a cloth or
paper towel can be used;
(Continued)
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Vehicle Care 431
Warning (Continued)
however, use a scraper
or wire brush later to
remove all rust or dirt.
Lightly coat the center of
the wheel hub with wheel
bearing grease after a
wheel change or tire
rotation to prevent
corrosion or rust build-up.
{Warning
Do not apply grease to
the wheel mounting
surface, wheel conical
seats, or the wheel nuts
or bolts. Grease applied
to these areas could
cause a wheel to become
loose or come off,
resulting in a crash.
When It Is Time for
New Tires
Factors, such as maintenance,
temperatures, driving speeds,
vehicle loading, and road
conditions affect the wear
rate of the tires.
Treadwear indicators are one
way to tell when it is time for
new tires. Treadwear
indicators appear when the
tires have only 1.6 mm (1/16 in)
or less of tread remaining. See
Tire Inspection 0429 and
Tire Rotation 0429. The rubber in tires ages over
time. This also applies to the
spare tire, if the vehicle has
one, even if it is never used.
Multiple factors including
temperatures, loading
conditions, and inflation
pressure maintenance affect
how fast aging takes place.
GM recommends that tires,
including the spare if
equipped, be replaced after six
years, regardless of tread
wear. To identify the age of a
tire, use the tire manufacture
date, which is the last four
digits of the DOT Tire
Identification Number (TIN)
molded into one side of the
tire sidewall. The last four
digits of the TIN indicate the
tire manufactured date. The
first two digits represent the
week and the last two digits,
the year. For example, the
third week of the year 2020
would have a 4-digit DOT date
of 0320. Week 01 is the first
full week (Sunday through
Saturday) of each year.
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432 Vehicle Care
Vehicle Storage
Tires age when stored
normally mounted on a parked
vehicle. Park a vehicle that will
be stored for at least a month
in a cool, dry, clean area away
from direct sunlight to slow
aging. This area should be free
of grease, gasoline, or other
substances that can
deteriorate rubber.
Parking for an extended
period can cause flat spots on
the tires that may result in
vibrations while driving. When
storing a vehicle for at least a
month, remove the tires or
raise the vehicle to reduce the
weight from the tires.
Buying New Tires
GM has developed and
matched specific tires for
the vehicle. The original
equipment tires installed
were designed to meet
General Motors Tire
Performance CriteriaSpecification (TPC Spec)
system rating. When
replacement tires are
needed, GM strongly
recommends buying tires
with the same TPC Spec
rating.
GM's exclusive TPC Spec
system considers over a
dozen critical specifications
that impact the overall
performance of the vehicle,
including brake system
performance, ride and
handling, traction control,
and tire pressure
monitoring performance.
GM's TPC Spec number is
molded onto the tire's
sidewall near the tire size.
If the tires have an
all-season tread design, the
TPC Spec number will be
followed by MS for mud
and snow. See Tire
Sidewall Labeling
0417 for
additional information. GM recommends replacing
worn tires in complete sets
of four. Uniform tread
depth on all tires will help
to maintain the
performance of the vehicle.
Braking and handling
performance may be
adversely affected if all the
tires are not replaced at
the same time. If proper
rotation and maintenance
have been done, all four
tires should wear out at
about the same time.
However, if it is necessary
to replace only one axle set
of worn tires, place the
new tires on the rear axle.
See Tire Rotation
0429.{Warning
Tires could explode
during improper service.
Attempting to mount or
dismount a tire could
(Continued)
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Vehicle Care 433
Warning (Continued)
cause injury or death.
Only your dealer or
authorized tire service
center should mount or
dismount the tires.
{Warning
Mixing tires of different
sizes (other than those
originally installed on the
vehicle), brands, tread
patterns, or types may
cause loss of vehicle
control, resulting in a
crash or other vehicle
damage. Use the correct
size, brand, and type of
tire on all wheels.
{Warning
Using bias-ply tires on
the vehicle may cause the
wheel rim flanges to
develop cracks after
many miles of driving.
A tire and/or wheel could
fail suddenly and cause a
crash. Use only radial-ply
tires with the wheels on
the vehicle.
Winter tires with the same
speed rating as the original
equipment tires may not be
available for H, V, W, Y and
ZR speed rated tires. Never
exceed the winter tires’
maximum speed capability
when using winter tires
with a lower speed rating.
If the vehicle tires must be
replaced with a tire that
does not have a TPC Spec
number, make sure they
are the same size, load range, speed rating, and
construction (radial) as the
original tires.
The Tire and Loading
Information label indicates
the original equipment tires
on the vehicle. See Vehicle
Load Limits
0255.
Different Size Tires
and Wheels
If wheels or tires are installed
that are a different size than
the original equipment wheels
and tires, vehicle performance,
including its braking, ride and
handling characteristics,
stability, and resistance to
rollover may be affected. If the
vehicle has electronic systems
such as antilock brakes,
rollover airbags, traction
control, electronic stability
control, or All-Wheel Drive, the
performance of these systems
can also be affected.
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434 Vehicle Care
{Warning
If different sized wheels are
used, there may not be an
acceptable level of
performance and safety if
tires not recommended for
those wheels are selected.
This increases the chance of
a crash and serious injury.
Only use GM specific wheel
and tire systems developed
for the vehicle, and have
them properly installed by a
GM certified technician.
See Buying New Tires 0432
and
Accessories and Modifications
0 370.
Uniform Tire Quality
Grading
The following information
relates to the system
developed by the United
States National Highway
Traffic Safety Administration (NHTSA),
which grades tires by
treadwear, traction, and
temperature performance.
This applies only to
vehicles sold in the United
States. The grades are
molded on the sidewalls of
most passenger car tires.
The Uniform Tire Quality
Grading (UTQG) system
does not apply to deep
tread, winter tires, compact
spare tires, tires with
nominal rim diameters of
10 to 12 inches
(25 to 30 cm), or to some
limited-production tires.
While the tires available on
General Motors passenger
cars and light trucks may
vary with respect to these
grades, they must also
conform to federal safety
requirements and
additional General Motors
Tire Performance Criteria
(TPC) standards.
Quality grades can be
found where applicable on
the tire sidewall between
tread shoulder and
maximum section width.
For example:
Treadwear 200 Traction AA
Temperature A
All Passenger Car Tires
Must Conform to Federal
Safety Requirements In
Addition To These Grades.
Treadwear
The treadwear grade is a
comparative rating based
on the wear rate of the tire
when tested under
controlled conditions on a
specified government test
course. For example, a tire
graded 150 would wear one
and one-half (1½) times as
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Vehicle Care 435
well on the government
course as a tire graded
100. The relative
performance of tires
depends upon the actual
conditions of their use,
however, and may depart
significantly from the norm
due to variations in driving
habits, service practices
and differences in road
characteristics and climate.
Traction
The traction grades, from
highest to lowest, are AA,
A, B, and C. Those grades
represent the tire's ability
to stop on wet pavement
as measured under
controlled conditions on
specified government test
surfaces of asphalt and
concrete. A tire marked C
may have poor traction
performance. Warning: The
traction grade assigned tothis tire is based on
straight-ahead braking
traction tests, and does not
include acceleration,
cornering, hydroplaning,
or peak traction
characteristics.
Temperature
The temperature grades
are A (the highest), B, and
C, representing the tire's
resistance to the
generation of heat and its
ability to dissipate 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
temperature can lead to
sudden tire failure. The
grade C corresponds to a
level of performance whichall passenger car tires must
meet under the Federal
Motor Safety Standard
No. 109. Grades B and A
represent higher levels of
performance on the
laboratory test wheel than
the minimum required by
law. Warning: The
temperature grade for this
tire is established for a tire
that is properly inflated and
not overloaded. Excessive
speed, underinflation,
or excessive loading, either
separately or in
combination, can cause
heat buildup and possible
tire failure.
Wheel Alignment and
Tire Balance
The tires and wheels were
aligned and balanced at the
factory to provide the longest
tire life and best overall
performance. Adjustments to
wheel alignment and tire
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436 Vehicle Care
balancing are not necessary
on a regular basis. Consider an
alignment check if there is
unusual tire wear or the
vehicle is significantly pulling
to one side or the other. Some
slight pull to the left or right,
depending on the crown of the
road and/or other road
surface variations such as
troughs or ruts, is normal.
If the vehicle is vibrating when
driving on a smooth road, the
tires and wheels may need to
be rebalanced. See your
dealer for proper diagnosis.
Wheel Replacement
Replace any wheel that is
bent, cracked, or badly rusted
or corroded. If wheel nuts
keep coming loose, the wheel,
wheel bolts, and wheel nuts
should be replaced. If the
wheel leaks air, replace it.
Some aluminum wheels can be
repaired. See your dealer if
any of these conditions exist.
Your dealer will know the kind
of wheel that is needed.Each new wheel should have
the same load-carrying
capacity, diameter, width,
offset, and be mounted the
same way as the one it
replaces.
Replace wheels, wheel bolts,
wheel nuts, or Tire Pressure
Monitor System (TPMS)
sensors with new GM original
equipment parts.
{Warning
Using the wrong
replacement wheels, wheel
bolts, or wheel nuts can be
dangerous. It could affect
the braking and handling of
the vehicle. Tires can lose air
and cause loss of control,
resulting in a crash. Always
use the correct wheel, wheel
bolts, and wheel nuts for
replacement.
{Warning
Replacing a wheel with a
used one is dangerous. How
it has been used or how far
it has been driven may be
unknown. It could fail
suddenly and cause a crash.
When replacing wheels, use
a new GM original
equipment wheel.
Caution
The wrong wheel can also
cause problems with bearing
life, brake cooling,
speedometer or odometer
calibration, headlamp aim,
bumper height, vehicle
ground clearance, and tire or
tire chain clearance to the
body and chassis.