2023 CADILLAC CT4 light

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
408 Vehicle Care
Fuses Usage
1 Long Range RadarFront Sensor
2 Park/Daytime Running Lamps
3 Exterior Lighting Module 4
4 Exterior Lighting Module 7
5 Headlamp Level
6 –
Fuses Usage
7 Electronic Brake
Control Module
8 Washer Pump
9 –
10 –
11 –
12 Horn
13 Front Wiper
Fuses Usage
14 Exterior Lighting Module 6
15 Exterior Lighting Module 1
16 Exterior Lighting Module 5
17 Exterior Lighting Module 3
18 Aero Shutter
19 –
20 –
21 Virtual Key System/ Power Sounder
Module
22 Engine Control Module Battery
23 Transmission Control Module
24 Active Engine Mount
25 –
26 Engine Control Module
27 Injectors/Ignition 2
28 Charged Air Cooler/ Not Used
29 Transmission Aux Oil Pump/Transmission
Reverse Lock Out

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Vehicle Care 413
Fuses Usage
35 Hands Free ClosureRelease
36 Exterior Lighting Module 2
37 Passenger Memory Seat Module
38 –
39 Right Front/Right Rear Window
40 –
41 –
42 Amplifier
43 Park Assist Module
44 Driver Memory Seat Module
45 OnStar
46 –
47 –
48 –
49 –
50 Driver Seat 51 Left Front/Left Rear Window
52 Passenger Seat
Relays Usage
53 –
54 –
55 Run
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
(Continued)
Warning (Continued) flexing. There could be
a blowout and a serious
crash. See Vehicle Load
Limits 0255.
.Underinflated tires
pose the same danger
as overloaded tires. The
resulting crash 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.
(Continued)

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
420 Vehicle Care
DOT Markings:A code
molded into the sidewall of
a tire signifying that the
tire is in compliance with
the U.S. Department of
Transportation (DOT)
Motor Vehicle Safety
Standards. The DOT code
includes the Tire
Identification Number (TIN),
an alphanumeric designator
which can also identify the
tire manufacturer,
production plant, brand,
and date of production.
GVWR
:Gross Vehicle
Weight Rating. See Vehicle
Load Limits 0255.
GAWR FRT
:Gross Axle
Weight Rating for the front
axle. See Vehicle Load
Limits 0255.
GAWR RR
:Gross Axle
Weight Rating for the rear
axle. See Vehicle Load
Limits 0255. Intended Outboard
Sidewall
:The side of an
asymmetrical tire, that
must always face outward
when mounted on a vehicle.
Kilopascal (kPa)
:The
metric unit for air pressure.
Light Truck (LT-Metric)
Tire
:A tire used on light
duty trucks and some
multipurpose passenger
vehicles.
Load Index
:An assigned
number ranging from 1 to
279 that corresponds to
the load carrying capacity
of a tire.
Maximum Inflation
Pressure
:The maximum
air pressure to which a cold
tire can be inflated. The
maximum air pressure is
molded onto the sidewall. Maximum Load Rating
:
The load rating for a tire at
the maximum permissible
inflation pressure for
that tire.
Occupant Distribution
:
Designated seating
positions.
Outward Facing Sidewall
:
The side of an
asymmetrical tire that has
a particular side that faces
outward when mounted on
a vehicle. The side of the
tire that contains a
whitewall, bears white
lettering, or bears
manufacturer, brand, and/
or model name molding
that is higher or deeper
than the same moldings on
the other sidewall of
the tire.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Vehicle Care 421
Passenger (P-Metric)
Tire
:A tire used on
passenger cars and some
light duty trucks and
multipurpose vehicles.
Recommended Inflation
Pressure
:Vehicle
manufacturer's
recommended tire inflation
pressure as shown on the
tire placard. See Tire
Pressure 0422 and
Vehicle Load Limits 0255.
Radial Ply Tire
:A
pneumatic tire in which the
ply cords that extend to
the beads are laid at
90 degrees to the
centerline of the tread.
Rim
:A metal support for a
tire and upon which the tire
beads are seated.
Sidewall
:The portion of a
tire between the tread and
the bead. Speed Rating
:An
alphanumeric code
assigned to a tire indicating
the maximum speed at
which a tire can operate.
Traction
:The friction
between the tire and the
road surface. The amount
of grip provided.
Tread
:The portion of a
tire that comes into
contact with the road.
Treadwear Indicators
:
Narrow bands, sometimes
called wear bars, that show
across the tread of a tire
when only 1.6 mm (1/16 in)
of tread remains. See
When It Is Time for New
Tires 0431.
UTQGS (Uniform Tire
Quality Grading
Standards)
:A tire
information system that
provides consumers with
ratings for a tire's traction, temperature, and
treadwear. Ratings are
determined by tire
manufacturers using
government testing
procedures. The ratings
are molded into the
sidewall of the tire. See
Uniform Tire Quality
Grading
0434.
Vehicle Capacity Weight
:
The number of designated
seating positions multiplied
by 68 kg (150 lbs) plus the
rated cargo load. See
Vehicle Load Limits 0255.
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's capacity weight

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
426 Vehicle Care
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 Limits0255.
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 pressure.
Using the DIC, tire pressure
levels can be viewed. For
additional information and
details about the DIC
operation and displays see
Driver Information Center
(DIC) (Base Level)
0129 or
Driver Information Center
(DIC) (Uplevel) 0132.
The low tire pressure warning
light may come on in cool
weather when the vehicle is
first started, and then turn off
as the vehicle is driven. This
could be an early indicator
that the air pressure is getting
low and needs to be inflated to
the proper pressure.
A Tire and Loading
Information label, attached to
your vehicle, shows the size of
the original equipment tires
and the correct inflation
pressure for the tires when
they are cold. See Vehicle
Load Limits 0255, for an
example of the Tire and Loading Information label and
its location. Also see Tire
Pressure
0422.
The TPMS can warn about a
low tire pressure condition but
it does not replace normal tire
maintenance. See Tire
Inspection 0429, Tire Rotation
0 429, and Tires 0413.Caution
Tire sealant materials are
not all the same.
A non-approved tire sealant
could damage the TPMS
sensors. TPMS sensor
damage caused by using an
incorrect tire sealant is not
covered by the vehicle
warranty. Always use only
the GM approved tire
sealant available through
your dealer or included in
the vehicle.
Factory-installed Tire Inflator
Kits use a GM-approved liquid
tire sealant. Using
non-approved tire sealants

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Vehicle Care 427
could damage the TPMS
sensors. See Tire Sealant and
Compressor Kit0439 for
information regarding the
inflator kit materials and
instructions.
TPMS Malfunction Light
and Message
The TPMS will not function
properly if one or more of the
TPMS sensors are missing or
inoperable. When the system
detects a malfunction, the low
tire pressure warning light
flashes for about one minute
and then stays on for the
remainder of the ignition cycle.
A DIC warning message also
displays. The malfunction light
and DIC warning message
come on at each ignition cycle
until the problem is corrected.
Some of the conditions that
can cause these to come
on are:
.One of the road tires has
been replaced with the
spare tire. The spare tire
does not have a TPMS sensor. The malfunction light
and DIC message should go
off after the road tire is
replaced and the sensor
matching process is
performed successfully. See
“TPMS Sensor Matching
Process”
later in this section.
.The TPMS sensor matching
process was not done or not
completed successfully after
rotating the tires. The
malfunction light and the DIC
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. See
Buying New Tires
0432.
.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.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
428 Vehicle Care
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 (Continued)
Warning (Continued)
maximum pressure listed on
the tire sidewall. See Tire
Sidewall Labeling 0417 and
Vehicle Load Limits 0255.
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.
The TPMS will not activate the
tire fill alert properly under the
following conditions:
.There is interference from
an external device or
transmitter.
.The air pressure from the
inflation device is not
sufficient to inflate the tire.
.There is a malfunction in
the TPMS.
.There is a malfunction in the
horn or turn signal lamps.
.The identification code of
the TPMS sensor is not
registered to the system.
.The battery of the TPMS
sensor is low.
If the tire fill alert does not
operate due to TPMS
interference, move the vehicle
about 1 m (3 ft) back or
forward and try again. If the

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
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.