tire size CADILLAC CT4 2021 Owner's Manual

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
58 SEATS AND RESTRAINTS
Adding Equipment to the
Airbag-Equipped Vehicle
Adding accessories that change the
vehicle's frame, bumper system,
height, front end, or side sheet metal
may keep the airbag system from
working properly.
The operation of the airbag system
can also be affected by changing,
including improperly repairing or
replacing, any parts of the following:
.Airbag system, including airbag
modules, front or side impact
sensors, sensing and diagnostic
module, or airbag wiring
.Front seats, including stitching,
seams or zippers
.Seat belts
.Steering wheel, instrument panel,
overhead console, ceiling trim,
or pillar garnish trim
.Inner door seals, including speakers
Your dealer and the service manual
have information about the location of
the airbag modules and sensors, sensing and diagnostic module, and
airbag wiring along with the proper
replacement procedures.
In addition, the vehicle has a
passenger sensing system for the front
outboard passenger position, which
includes sensors that are part of the
passenger seat. The passenger sensing
system may not operate properly if
the original seat trim is replaced with
non-GM covers, upholstery, or trim; or
with GM covers, upholstery, or trim
designed for a different vehicle. Any
object, such as an aftermarket seat
heater or a comfort-enhancing pad or
device, installed under or on top of
the seat fabric, could also interfere
with the operation of the passenger
sensing system. This could either
prevent proper deployment of the
passenger airbag(s) or prevent the
passenger sensing system from
properly turning off the passenger
airbag(s). See
Passenger Sensing
System 053.
If the vehicle has rollover roof-rail
airbags, see Different Size Tires and
Wheels 0356 for additional important
information. If the vehicle must be modified
because you have a disability and have
questions about whether the
modifications will affect the vehicle's
airbag system, or if you have
questions about whether the airbag
system will be affected if the vehicle is
modified for any other reason, call
Customer Assistance. See
Customer
Assistance Offices 0401.
Airbag System Check
The airbag system does not need
regularly scheduled maintenance or
replacement. Make sure the airbag
readiness light is working. See Airbag
Readiness Light 096.
Caution
If an airbag covering is damaged,
opened, or broken, the airbag may
not work properly. Do not open or
break the airbag coverings. If there
are any opened or broken airbag
coverings, have the airbag covering
and/or airbag module replaced. For
the location of the airbags, see
Where Are the Airbags? 049. See
your dealer for service.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
DRIVING AND OPERATING 203
Automatic EmergencyBraking (AEB) . . . . . . . . . . . . . . . . . . . 285
Front Pedestrian Braking (FPB) System . . . . . . . . . . . . . . . . . . . . . . . . . . 287
Side Blind Zone Alert (SBZA) . . . . 289
Lane Change Alert (LCA) . . . . . . . . 289
Lane Keep Assist (LKA) . . . . . . . . . . 291
Fuel
Top Tier Fuel . . . . . . . . . . . . . . . . . . . . . 293
Recommended Fuel (LSY 2.0L L4
Turbo Engine) . . . . . . . . . . . . . . . . . . . 293
Recommended Fuel (L3B 2.7L L4 Turbo Engine) . . . . . . . . . . . . . . . . . . . 294
Prohibited Fuels . . . . . . . . . . . . . . . . . . 294
Fuels in Foreign Countries . . . . . . . 294
Fuel Additives . . . . . . . . . . . . . . . . . . . . 294
Filling the Tank . . . . . . . . . . . . . . . . . . 295
Filling a Portable Fuel Container . . . . . . . . . . . . . . . . . . . . . . . . 296
Trailer Towing
General Towing Information . . . . 297
Driving Characteristics andTowing Tips . . . . . . . . . . . . . . . . . . . . . 297
Trailer Towing (LSY 2.0L L4 Engine) . . . . . . . . . . . . . . . . . . . . . . . . . . 300
Towing Equipment . . . . . . . . . . . . . . . 302
Conversions and Add-Ons
Add-On Electrical Equipment . . . 303
Driving Information
Driving for Better Fuel
Economy
Driving habits can affect fuel mileage.
Here are some driving tips to get the
best fuel economy possible:
.Set the climate controls to the
desired temperature after the engine
is started, or turn them off when
not required.
.Avoid fast starts and accelerate
smoothly.
.Brake gradually and avoid abrupt
stops.
.Avoid idling the engine for long
periods of time.
.When road and weather conditions
are appropriate, use cruise control.
.Always follow posted speed limits or
drive more slowly when conditions
require.
.Keep vehicle tires properly inflated.
.Combine several trips into a
single trip.
.Replace the vehicle's tires with the
same TPC Spec number molded into
the tire's sidewall near the size.
.Follow recommended scheduled
maintenance.
Distracted Driving
Distraction comes in many forms and
can take your focus from the task of
driving. Exercise good judgment and
do not let other activities divert your
attention away from the road. Many
local governments have enacted laws
regarding driver distraction. Become
familiar with the local laws in
your area.
To avoid distracted driving, keep your
eyes on the road, keep your hands on
the steering wheel, and focus your
attention on driving.
.Do not use a phone in demanding
driving situations. Use a hands-free
method to place or receive
necessary phone calls.
.Watch the road. Do not read, take
notes, or look up information on
phones or other electronic devices.
.Designate a front seat passenger to
handle potential distractions.

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DRIVING AND OPERATING 215
Warning (Continued)
This could cause loss of control
and a crash. Overloading can
also reduce stopping
performance, damage the tires,
and shorten the life of the
vehicle.
Tire and Loading Information
Label
Label Example
A vehicle-specific Tire and
Loading Information label is
attached to the vehicle's center pillar (B-pillar). The Tire and
Loading Information label shows
the number of occupant seating
positions (1), and the maximum
vehicle capacity weight (2) in
kilograms and pounds.
The Tire and Loading Information
label also shows the tire size of
the original equipment tires (3)
and the recommended cold tire
inflation pressures (4). For more
information on tires and inflation
see
Tires 0339 and
Tire Pressure 0346.
There is also important loading
information on the Certification
label. It may show the Gross
Vehicle Weight Rating (GVWR)
and the Gross Axle Weight Rating
(GAWR) for the front and rear
axle. See “Certification Label” later
in this section. “Steps for Determining Correct
Load Limit–
1.Locate the statement "The
combined weight of occupants
and cargo should never exceed
XXX kg or XXX lbs." on your
vehicle’s placard.
2.Determine the combined weight
of the driver and passengers
that will be riding in your
vehicle.
3.Subtract the combined weight
of the driver and passengers
from XXX kg or XXX lbs.
4.The resulting figure equals the
available amount of cargo and
luggage load capacity. For
example, if the "XXX" amount
equals 1400 lbs. and there will
be five 150 lb passengers in
your vehicle, the amount of
available cargo and luggage
load capacity is 650 lbs.
(1400-750 (5 x 150) = 650 lbs.)

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DRIVING AND OPERATING 289
{Warning
FPB may alert or automatically
brake the vehicle suddenly in
situations where it is unexpected
and undesired. It could falsely alert
or brake for objects similar in shape
or size to pedestrians, including
shadows. This is normal operation
and the vehicle does not need
service. To override Automatic
Braking, firmly press the accelerator
pedal, if it is safe to do so.
Automatic Braking can be disabled
through vehicle personalization. See
“Front Pedestrian Detection ”in
“Collision/Detection Systems” under
Vehicle Personalization 0117.
{Warning
Using the Front Pedestrian Braking
system while towing a trailer could
cause you to lose control of the
vehicle and crash. Turn the system
to Alert or Off when towing a
trailer.
Cleaning the System
If FPB does not seem to operate
properly, cleaning the outside of the
windshield in front of the rearview
mirror may correct the issue.
Side Blind Zone
Alert (SBZA)
If equipped, the SBZA system is a
lane-changing aid that assists drivers
with avoiding crashes that occur with
moving vehicles in the side blind
zone, or blind spot areas. When the
vehicle is in a forward gear, the left or
right side mirror display will light up
if a moving vehicle is detected in that
blind zone. If the turn signal is
activated and a vehicle is also
detected on the same side, the display
will flash as an extra warning not to
change lanes. Since this system is part
of the Lane Change Alert (LCA)
system, read the entire LCA section
before using this feature.
Lane Change Alert (LCA)
If equipped, the LCA system is a
lane-changing aid that assists drivers
with avoiding lane change crashes
that occur with moving vehicles in the
side blind zone (or spot) areas or with
vehicles rapidly approaching these
areas from behind. The LCA warning
display will light up in the
corresponding outside mirror and will
flash if the turn signal is on.
{Warning
LCA does not alert the driver to
vehicles outside of the system
detection zones, pedestrians,
bicyclists, or animals. It may not
provide alerts when changing lanes
under all driving conditions. Failure
to use proper care when changing
lanes may result in injury, death,
or vehicle damage. Before making a
lane change, always check mirrors,
glance over your shoulder, and use
the turn signals.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
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304 VEHICLE CARE
Vehicle Care
General Information
General Information . . . . . . . . . . . . . 305
California Proposition65 Warning . . . . . . . . . . . . . . . . . . . . . 305
California Perchlorate Materials Requirements . . . . . . . . . . . . . . . . . . . 306
Accessories and Modifications . . . . . . . . . . . . . . . . . . . 306
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . . . . . . 306
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . . . . . . 309
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . 312
Engine Oil Life System . . . . . . . . . . . 314
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315
Engine Air Filter Life System . . . . 315
Engine Air Cleaner/Filter . . . . . . . . . 316
Cooling System . . . . . . . . . . . . . . . . . . . 317
Engine Overheating . . . . . . . . . . . . . . 322
Washer Fluid . . . . . . . . . . . . . . . . . . . . . 323
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323 Brake Pad Life System (If
Equipped) . . . . . . . . . . . . . . . . . . . . . . . 324
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . 325
Battery - North America . . . . . . . . . 326
All-Wheel Drive . . . . . . . . . . . . . . . . . . 327
Park Brake and P (Park) Mechanism Check . . . . . . . . . . . . . . 327
Wiper Blade Replacement . . . . . . . 327
Windshield Replacement . . . . . . . . 328
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . 328
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . 329
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . 329
Halogen Bulbs . . . . . . . . . . . . . . . . . . . . 330
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . . . . . . . . . . . . . 330
LED Lighting . . . . . . . . . . . . . . . . . . . . . 330
Front Turn Signal Lamps . . . . . . . . 330
Electrical System
Electrical System Overload . . . . . . 330
Fuses and Circuit Breakers . . . . . . 331
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
Instrument Panel Fuse Block . . . . 334
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339
All-Season Tires . . . . . . . . . . . . . . . . . . 339
Winter Tires . . . . . . . . . . . . . . . . . . . . . . 340
Run-Flat Tires . . . . . . . . . . . . . . . . . . . . 340
Self-Sealing Tires . . . . . . . . . . . . . . . . . 341
Low-Profile Tires . . . . . . . . . . . . . . . . . 341
Summer Tires . . . . . . . . . . . . . . . . . . . . 341
Tire Sidewall Labeling . . . . . . . . . . . 342
Tire Designations . . . . . . . . . . . . . . . . . 343
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . . . . . . . 344
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . 346
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . . . . . . 347
Tire Pressure Monitor System . . . 348
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . . . . . . 349
Tire Inspection . . . . . . . . . . . . . . . . . . . 352
Tire Rotation . . . . . . . . . . . . . . . . . . . . . 352
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353
Buying New Tires . . . . . . . . . . . . . . . . 354
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . . . . . 356
Uniform Tire Quality Grading . . . 356
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . . . . . . 357

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
340 VEHICLE CARE
all-season tires can be identified by
the last two characters of this TPC
code, which will be“MS.”
Consider installing winter tires on the
vehicle if frequent driving on snow or
ice-covered roads is expected.
All-season tires provide adequate
performance for most winter driving
conditions, but they may not offer the
same level of traction or performance
as winter tires on snow or ice-covered
roads. See Winter Tires 0340.
Winter Tires
This vehicle was not originally
equipped with winter tires. Winter
tires are designed for increased
traction on snow and ice-covered
roads. Consider installing winter tires
on the vehicle if frequent driving on
ice or snow covered roads is expected.
See your dealer for details regarding
winter tire availability and proper tire
selection. Also, see Buying New Tires
0 354.
With winter tires, there may be
decreased dry road traction, increased
road noise, and shorter tread life. After changing to winter tires, be alert
for changes in vehicle handling and
braking.
If using winter tires:
.Use tires of the same brand and
tread type on all four wheel
positions.
.Use only radial ply tires of the same
size, load range, and speed rating as
the original equipment tires.
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. If winter
tires with a lower speed rating are
chosen, never exceed the tire's
maximum speed capability.
Run-Flat Tires
This vehicle, when new, may have had
run-flat tires. There is no spare tire,
no tire changing equipment, and no
place to store a tire in the vehicle.
{Warning
While driving with run-flat tires at
a reduced inflation pressure, avoid
making sudden stops or severe
maneuvers as the handling
capabilities of the tires will be
reduced. Driving too fast could
cause loss of control and you or
others could be injured. Do not
drive over 80 km/h (50 mph) with
the tire operating at low pressure.
Drive cautiously and check the tire
pressure as soon as possible.
Run-flat tires can be driven up to
80 km (50 mi) at speeds less than
80 km/h (50 mph) after a loss of
inflation pressure has occurred. There
is no need to stop on the side of the
road to change the tire. The possible
driving range after a pressure loss will
vary based on the vehicle load and
driving conditions. As soon as
possible, contact the nearest
authorized GM or run-flat servicing
facility for inspection and repair or
replacement.

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VEHICLE CARE 341
When driving on a deflated run-flat
tire, avoid potholes and other road
hazards that could damage the tire
and/or wheel beyond repair. When a
tire has been damaged, or if driven
any distance while deflated, check
with an authorized run-flat tire
service center to determine whether
the tire can be repaired or should be
replaced. To maintain the run-flat
feature, all replacement tires must be
run-flat tires.
To locate the nearest GM or run-flat
servicing facility, call Customer
Assistance.
Self-Sealing Tires
This vehicle may have self-sealing
tires. These tires have a material
inside that can seal punctures from
common road hazards, such as nails
and screws, in the tread area. The tire
may lose air pressure if the sidewall is
damaged or the tread puncture is too
large. If the Tire Pressure Monitor
System indicates the tire pressure is
low, inspect the tire for damage and
inflate it to the recommended
pressure. If the tire is unable to
maintain the recommended pressure,contact the nearest authorized GM
servicing facility immediately for
inspection and repair or replacement.
To locate the nearest GM servicing
facility, call GM Customer Assistance.
Caution
Do not drive on a deflated
self-sealing tire as this could
damage the tire. Make sure the tire
is inflated to the recommended
pressure or have it immediately
repaired or replaced.
When tire replacement is needed
replace with a self-sealing tire,
because the vehicle does not come
with a spare tire or tire changing
equipment.
Low-Profile Tires
If the vehicle has 225/45R17 91V,
235/40R18 91V, 235/40R18 XL
95Y, or 235/35R19 XL 91V size
tires, they are classified as
low-profile tires. Caution
Low-profile tires are more
susceptible to damage from road
hazards or curb impact than
standard profile tires. Tire and/or
wheel assembly damage can occur
when coming into contact with
road hazards like potholes, or sharp
edged objects, or when sliding into
a curb. The warranty does not cover
this type of damage. Keep tires set
to the correct inflation pressure and
when possible, avoid contact with
curbs, potholes, and other road
hazards.
Summer Tires
High Performance Summer Tires
This vehicle may come with
235/40R18 XL 95Y high performance
summer tires. These tires have a
special tread and compound that are
optimized for maximum dry and wet
road performance. This special tread
and compound will have decreased
performance in cold climates, and on
ice and snow. It is recommended that
winter tires be installed on the vehicle

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
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342 VEHICLE CARE
if frequent driving at temperatures
below approximately 5 °C (40 °F) or on
ice or snow covered roads is expected.
SeeWinter Tires 0340.
Caution
High performance summer tires
have rubber compounds that lose
flexibility and may develop surface
cracks in the tread area at
temperatures below −7 °C (20 °F).
Always store high performance
summer tires indoors and at
temperatures above −7 °C (20 °F)
when not in use. If the tires have
been subjected to −7 °C (20 °F) or
less, let them warm up in a heated
space to at least 5 °C (40 °F) for
24 hours or more before being
installed or driving a vehicle on
which they are installed. Do not
apply heat or blow heated air
directly on the tires. Always inspect
tires before use. See Tire Inspection
0 352.
Tire Sidewall Labeling
Useful information about a tire is
molded into its sidewall. The
example shows a typical passenger
tire sidewall.
Passenger (P-Metric) Tire Example
(1) Tire Size:The tire size is a
combination of letters and
numbers used to define a
particular tire's width, height,
aspect ratio, construction type,
and service description. See the
“Tire Size ”illustration later in this
section. (2) TPC Spec (Tire Performance
Criteria Specification)
:Original
equipment tires designed to GM's
specific tire performance criteria
have a TPC specification code
molded onto the sidewall. GM's
TPC specifications meet or exceed
all federal safety guidelines.
(3) DOT (Department of
Transportation)
:The
Department of Transportation
(DOT) code indicates that the tire
is in compliance with the U.S.
Department of Transportation
Motor Vehicle Safety Standards.
DOT Tire Date of Manufacture
:
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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VEHICLE CARE 343
(4) Tire Identification Number
(TIN)
:The letters and numbers
following the DOT code are the
Tire Identification Number (TIN).
The TIN shows the manufacturer
and plant code, tire size, and date
the tire was manufactured. The
TIN is molded onto both sides of
the tire, although only one side
may have the date of
manufacture.
(5) Tire Ply Material
:The type
of cord and number of plies in the
sidewall and under the tread.
(6) Uniform Tire Quality
Grading (UTQG)
:Tire
manufacturers are required to
grade tires based on three
performance factors: treadwear,
traction, and temperature
resistance. For more information
see Uniform Tire Quality Grading
0 356. (7) Maximum Cold Inf lation
Load Limit
:Maximum load that
can be carried and the maximum
pressure needed to support
that load.
Tire Designations
Tire Size
The example shows a typical
passenger vehicle tire size.
Passenger (P-Metric) Tire
(1) Passenger (P-Metric) Tire:
The United States version of a
metric tire sizing system. The
letter "P" as the first character in
the tire size means a passenger
vehicle tire engineered to
standards set by the U.S. Tire and
Rim Association. (2) Tire Width
:The 3-digit
number indicates the tire section
width in millimeters from sidewall
to sidewall.
(3) Aspect Ratio
:A 2-digit
number that indicates the tire
height-to-width measurements.
For example, if the tire size aspect
ratio is 75, as shown in item (3) of
the illustration, it would mean
that the tire's sidewall is
75 percent as high as it is wide.
(4) Construction Code
:A letter
code is used to indicate the type
of ply construction in the tire. The
letter "R" means radial ply
construction; the letter "D" means
diagonal or bias ply construction.
(5) Rim Diameter
:Diameter of
the wheel in inches.
(6) Service Description
:These
characters represent the load
index and speed rating of the tire.
The load index represents the load
carrying capacity a tire is certified

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346 VEHICLE CARE
treadwear. Ratings are determined
by tire manufacturers using
government testing procedures.
The ratings are molded into the
sidewall of the tire. SeeUniform
Tire Quality Grading 0356.
Vehicle Capacity Weight
:The
number of designated seating
positions multiplied by
68 kg (150 lb) plus the rated cargo
load. See Vehicle Load Limits 0214.
Vehicle Maximum Load on the
Tire
:Load on an individual tire
due to curb weight, accessory
weight, occupant weight, and
cargo weight.
Vehicle Placard
:A label
permanently attached to a vehicle
showing the vehicle capacity
weight and the original equipment
tire size and recommended
inflation pressure. See “Tire and
Loading Information Label” under
Vehicle Load Limits 0214.
Tire Pressure
Tires need the correct amount of
air pressure to operate effectively.
{Warning
Neither tire underinflation nor
overinflation is good.
Underinflated tires, or tires that
do not have enough air, can
result in:
.Tire overloading and
overheating, which could lead
to a blowout.
.Premature or irregular wear.
.Poor handling.
.Reduced fuel economy.
Overinflated tires, or tires that
have too much air, can result in:
.Unusual wear.
.Poor handling.
.Rough ride.
.Needless damage from road
hazards. The Tire and Loading Information
label on the vehicle indicates the
original equipment tires and the
correct cold tire inflation
pressures. The recommended
pressure is the minimum air
pressure needed to support the
vehicle's maximum load carrying
capacity. See
Vehicle Load Limits
0 214.
How the vehicle is loaded affects
vehicle handling and ride comfort.
Never load the vehicle with more
weight than it was designed to
carry.
When to Check
Check the pressure of the tires
once a month or more.
How to Check
Use a good quality pocket-type
gauge to check tire pressure.
Proper tire inflation cannot be
determined by looking at the tire.
Check the tire inflation pressure
when the tires are cold, meaning