2021 CADILLAC CT4 wheel

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
VEHICLE CARE 335
To install the end cover, insert the
tabs on the back of the cover into the
slots in the instrument panel at the
points shown. Align the clips with the
slots in the instrument panel, and
press the cover into place.
The vehicle may not be equipped with
all of the fuses and relays shown.
FusesUsage
1 –
2 HVAC blower
3 –
4 –
5 Theft deterrent/ Universal garage door
opener/Overhead
console/Rain sensor Fuses
Usage
6 –
7 Air quality ionizer
8 Heated steering wheel
9 –
10 Electronic steering column lock 1
11 –
12 –

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
336 VEHICLE CARE
FusesUsage
13 –
14 –
15 –
16 –
17 –
18 Display/Infotainment/ USB/Multi-function
control module
19 Airbag/ Automatic occupant sensing /
Data link connection/
Wireless charging
module/ Virtual key
module
20 Power steering column module/
Electronic steering
column lock 2
21 Driver monitor system/Performance
data recorder
22 –
23 –
24 – Fuses
Usage
25 USB
26 –
27 –
28 –
29 –
30 –
31 Headlamp level
32 –
33 Body ignition/IP ignition
34 Exhaust valve
35 Transmission control module ignition/
Engine control
module ignition/Shift
ignition/Brake
ignition
36 Shift module
37 Body control module 1/Electronic
park brake switch
38 Center stack module Fuses
Usage
39 Steering wheel controls
40 Body control module 2
41 Body control module 3
42 Body control module 4
Circuit
Breakers Usage
CB1 Auxiliary power outlet 1
CB2 Auxiliary power outlet 2
Relays Usage
1 Run after park/ Accessory
2 Run crank
3 –
4 –
5 –

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
VEHICLE CARE 339
Wheels and Tires
Tires
Every new GM vehicle has
high-quality tires made by a
leading tire manufacturer. See the
warranty manual for information
regarding the tire warranty and
where to get service. For
additional information refer to the
tire manufacturer.
{Warning
.Poorly maintained and
improperly used tires are
dangerous.
.Overloading the tires can
cause overheating as a result
of too much flexing. There
could be a blowout and a
serious crash. SeeVehicle
Load Limits 0214.
.Underinflated tires pose the
same danger as overloaded
tires. The resulting crash
(Continued)
Warning (Continued)
could cause serious injury.
Check all tires frequently to
maintain the recommended
pressure. Tire pressure should
be checked when the tires
are cold.
.Overinflated tires are more
likely to be cut, punctured,
or broken by a sudden impact
— such as when hitting a
pothole. Keep tires at the
recommended pressure.
.Worn or old tires can cause a
crash. If the tread is badly
worn, replace them.
.Replace any tires that have
been damaged by impacts
with potholes, curbs, etc.
.Improperly repaired tires can
cause a crash. Only the dealer
or an authorized tire service
(Continued)
Warning (Continued)
center should repair, replace,
dismount, and mount the
tires.
.Do not spin the tires in
excess of 56 km/h (35 mph)
on slippery surfaces such as
snow, mud, ice, etc. Excessive
spinning may cause the tires
to explode.
See Tire Pressure for High-Speed
Operation 0347 for inflation
pressure adjustment for
high-speed driving.
All-Season Tires
This vehicle may come with all-season
tires. These tires are designed to
provide good overall performance on
most road surfaces and weather
conditions. Original equipment tires
designed to GM's specific tire
performance criteria have a TPC
specification code molded onto the
sidewall. Original equipment

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.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
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) -
2021 - CRC - 11/23/20
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

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
VEHICLE CARE 349
soon as possible, and inflate them to
the proper pressure. Driving on a
significantly under-inflated tire causes
the tire to overheat and can lead to
tire failure. Under-inflation 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 responsibility to
maintain correct tire pressure, even if
under-inflation has not reached the
level to trigger illumination of the
TPMS low tire pressure 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 system detects a
malfunction, the telltale will flash for
approximately one minute and then
remain continuously illuminated. This
sequence will continue upon
subsequent vehicle start-ups as long
as the malfunction exists.When the malfunction indicator is
illuminated, 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 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.
See
Tire Pressure Monitor Operation
0 349.
See Radio Frequency Statement 0409.
Tire Pressure Monitor
Operation
This vehicle may have a Tire Pressure
Monitor System (TPMS). The TPMS is
designed to warn the driver when a
low tire pressure condition exists. TPMS sensors are mounted onto each
tire and wheel assembly, excluding the
spare tire and wheel assembly. The
TPMS sensors monitor the air
pressure in the tires and transmit the
tire pressure readings to a receiver
located in the vehicle.
When a low tire pressure condition is
detected, the TPMS illuminates the
low tire pressure warning light located
on the instrument cluster. If the
warning light comes on, stop as soon
as possible and inflate the tires to the
recommended pressure shown on the
Tire and Loading Information label.
See
Vehicle Load Limits 0214.
A message to check the pressure in a
specific tire displays in the Driver
Information Center (DIC). The low tire
pressure warning light and the DIC
warning message come on at each
ignition cycle until the tires are
inflated to the correct inflation

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
VEHICLE CARE 351
message should go off after
successfully completing the sensor
matching process. See "TPMS
Sensor Matching Process" later in
this section.
.One or more TPMS sensors are
missing or damaged. The
malfunction light and the DIC
message should go off when the
TPMS sensors are installed and the
sensor matching process is
performed successfully. See your
dealer for service.
.Replacement tires or wheels do not
match the original equipment tires
or wheels. Tires and wheels other
than those recommended could
prevent the TPMS from functioning
properly. SeeBuying New Tires
0 354.
.Operating electronic devices or
being near facilities using radio
wave frequencies similar to the
TPMS could cause the TPMS
sensors to malfunction.
If the TPMS is not functioning
properly it cannot detect or signal a
low tire pressure condition. See your dealer for service if the TPMS
malfunction light and DIC message
come on and stay on.
Tire Fill Alert (If Equipped)
This feature provides visual and
audible alerts outside the vehicle to
help when inflating an underinflated
tire to the recommended cold tire
pressure.
When the low tire pressure warning
light comes on:
1. Park the vehicle in a safe, level place.
2. Set the parking brake firmly.
3. Place the vehicle in P (Park).
4. Add air to the tire that is underinflated. The turn signal lamp
will flash.
When the recommended pressure
is reached, the horn sounds once
and the turn signal lamp will stop
flashing and briefly turn solid.
Repeat these steps for all
underinflated tires that have
illuminated the low tire pressure
warning light.
{Warning
Overinflating a tire could cause the
tire to rupture and you or others
could be injured. Do not exceed the
maximum pressure listed on the
tire sidewall. See Tire Sidewall
Labeling 0342 and
Vehicle Load Limits 0214.
If the tire is overinflated by more than
35 kPa (5 psi), the horn will sound
multiple times and the turn signal
lamp will continue to flash for several
seconds after filling stops. To release
and correct the pressure, while the
turn signal lamp is still flashing,
briefly press the center of the valve
stem. When the recommended
pressure is reached, the horn
sounds once.
If the turn signal lamp does not flash
within 15 seconds after starting to
inflate the tire, the tire fill alert has
not been activated or is not working.
If the hazard warning flashers are on,
the tire fill alert visual feedback will
not work properly.