2021 CADILLAC CT4 service

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Keys, Doors, and Windows . . . . . . . . . . 6
Seats and Restraints . . . . . . . . . . . . . . . 30
Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Instruments and Controls . . . . . . . . . . 81
Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Infotainment System . . . . . . . . . . . . . 134
Climate Controls . . . . . . . . . . . . . . . . . . 196
Driving and Operating . . . . . . . . . . . . 202
Vehicle Care . . . . . . . . . . . . . . . . . . . . . . . 304
Service and Maintenance . . . . . . . . . 379
Technical Data . . . . . . . . . . . . . . . . . . . . 395
Customer Information . . . . . . . . . . . . 399
Reporting Safety Defects . . . . . . . . . 409
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413
Connected Services . . . . . . . . . . . . . . . 418
Index . . . . . . . . . . . . . . . . . . . . . . . . 421
Introduction
The names, logos, emblems, slogans,
vehicle model names, and vehicle
body designs appearing in this manual
including, but not limited to, GM, the
GM logo, the CADILLAC Emblem, and
CADILLAC CT4 are trademarks and/or
service marks of General Motors LLC,
its subsidiaries, affiliates, or licensors.
For vehicles first sold in Canada,
substitute the name“General Motors
of Canada Company ”for Cadillac
Motor Car Division wherever it
appears in this manual.
This manual describes features that
may or may not be on the vehicle
because of optional equipment that
was not purchased on the vehicle,
model variants, country specifications, features/applications that may not be
available in your region, or changes
subsequent to the printing of this
owner’s manual.
Refer to the purchase documentation
relating to your specific vehicle to
confirm the features.
Keep this manual in the vehicle for
quick reference.
Canadian Vehicle Owners
A French language manual can be
obtained from your dealer, at
www.helminc.com, or from:
Propriétaires Canadiens
On peut obtenir un exemplaire de ce
guide en français auprès du
concessionnaire ou à l'adresse
suivante:
Helm, Incorporated
Attention: Customer Service
47911 Halyard Drive
Plymouth, MI 48170
USA
Litho in U.S.A.
Part No. 84432194 B Second Printing©2020 General Motors LLC. All Rights Reserved.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
2 INTRODUCTION
Using this Manual
To quickly locate information about
the vehicle, use the Index in the back
of the manual. It is an alphabetical
list of what is in the manual and the
page number where it can be found.
Danger, Warning, and
Caution
Warning messages found on vehicle
labels and in this manual describe
hazards and what to do to avoid or
reduce them.
{Danger
Danger indicates a hazard with a
high level of risk which will result
in serious injury or death.
{Warning
Warning indicates a hazard that
could result in injury or death.
Caution
Caution indicates a hazard that
could result in property or vehicle
damage.
A circle with a slash through it is a
safety symbol which means“Do not,”
“Do not do this,” or“Do not let this
happen.”
Symbols
The vehicle has components and
labels that use symbols instead of
text. Symbols are shown along with
the text describing the operation or
information relating to a specific
component, control, message, gauge,
or indicator.
M: Shown when the owner’s manual
has additional instructions or
information.
*: Shown when the service manual
has additional instructions or
information.
0: Shown when there is more
information on another page —
“see page.”
Vehicle Symbol Chart
Here are some additional symbols that
may be found on the vehicle and what
they mean. See the features in this
manual for information.
u: Air Conditioning System
G:Air Conditioning Refrigerant Oil
9:Airbag Readiness Light
!:Antilock Brake System (ABS)
$:Brake System Warning Light
9:Dispose of Used Components
Properly
P: Do Not Apply High Pressure
Water
B: Engine Coolant Temperature
_:Flame/Fire Prohibited

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
KEYS, DOORS, AND WINDOWS 7
The mechanical key, inside the remote
key, is used for the driver door and
glove box.To remove the mechanical key, press
the button on the side of the remote
key near the bottom, and pull the
mechanical key out. Never pull the
mechanical key out without pressing
the button.
If it becomes difficult to turn the key,
inspect the key blade for debris.
Periodically clean with a brush
or pick.
See your dealer if a new mechanical
key is needed.
Contact Roadside Service if locked out
of the vehicle. See
Roadside Service
0 403.
With an active OnStar or connected
service plan, an OnStar Advisor may
remotely unlock the vehicle. See
OnStar Overview 0413.
Remote Keyless Entry
(RKE) System
See Radio Frequency Statement 0409.
If there is a decrease in the remote
key operating range:
.Check the distance. The remote key
may be too far from the vehicle.
.Check the location. Other vehicles
or objects may be blocking the
signal.
.Check the remote key battery. See
“Battery Replacement ”later in this
section.
.If the remote key is still not working
correctly, see your dealer or a
qualified technician for service.
Remote Keyless Entry
(RKE) System Operation
The Keyless Access system allows for
vehicle entry when the remote key is
within 1 m (3 ft). See “Keyless Access
Operation ”later in this section.
The remote key functions may work
up to 60 m (197 ft) away from the
vehicle.
Other conditions can impact the
performance of the remote key. See
Remote Keyless Entry (RKE) System
0 7.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
KEYS, DOORS, AND WINDOWS 23
Immobilizer Operation
This vehicle has a passive
theft-deterrent system.
The system does not have to be
manually armed or disarmed.
The vehicle is automatically
immobilized when the vehicle is
turned off.
The immobilization system is
disarmed when the ignition is turned
on or to ACC/ACCESSORY and a valid
remote key is present in the vehicle.
The security light, in the instrument
cluster, comes on if there is a problem
with arming or disarming the
theft-deterrent system.
The system has one or more remote
keys matched to an immobilizer
control unit in the vehicle. Only a
correctly matched remote key willstart the vehicle. If the remote key is
ever damaged, you may not be able to
start your vehicle.
When trying to start the vehicle, the
security light may come on briefly.
If the engine does not start and the
security light stays on, there is a
problem with the system. Turn the
ignition off and try again.
If the vehicle will not change ignition
modes (ACC/ACCESSORY, on, off), and
the remote key appears to be
undamaged, try another remote key.
Or, you may try placing the remote
key in the backup location. See
Remote Keyless Entry (RKE) System
Operation
07.
If the ignition modes will not change
with the other remote key or in the
backup location, the vehicle needs
service. If the ignition does change
modes, the first remote key may be
faulty. See your dealer.
It is possible for the immobilizer
system to learn new or replacement
remote keys. Up to eight remote keys
can be programmed for the vehicle. To
program additional remote keys, see “Programming Remote Keys to the
Vehicle
”under Remote Keyless Entry
(RKE) System Operation 07.
Do not leave the remote key or device
that disarms or deactivates the
theft-deterrent system in the vehicle.
Exterior Mirrors
Convex Mirrors
{Warning
A convex mirror can make things,
like other vehicles, look farther
away than they really are. If you cut
too sharply into the right lane, you
could hit a vehicle on the right.
Check the inside mirror or glance
over your shoulder before changing
lanes.
The passenger side mirror is convex
shaped. A convex mirror's surface is
curved so more can be seen from the
driver seat.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
SEATS AND RESTRAINTS 53
{Warning
When an airbag inflates, there may
be dust in the air. This dust could
cause breathing problems for
people with a history of asthma or
other breathing trouble. To avoid
this, everyone in the vehicle should
get out as soon as it is safe to do
so. If you have breathing problems
but cannot get out of the vehicle
after an airbag inflates, then get
fresh air by opening a window or a
door. If you experience breathing
problems following an airbag
deployment, you should seek
medical attention.
The vehicle has a feature that may
automatically unlock the doors, turn
on the interior lamps and hazard
warning flashers, and shut off the fuel
system after the airbags inflate. The
feature may also activate, without
airbag inflation, after an event that
exceeds a predetermined threshold.
After turning the ignition off and then
on again, the fuel system will return
to normal operation; the doors can be locked, the interior lamps can be
turned off, and the hazard warning
flashers can be turned off using the
controls for those features. If any of
these systems are damaged in the
crash they may not operate as normal.
{Warning
A crash severe enough to inflate the
airbags may have also damaged
important functions in the vehicle,
such as the fuel system, brake and
steering systems, etc. Even if the
vehicle appears to be drivable after
a moderate crash, there may be
concealed damage that could make
it difficult to safely operate the
vehicle.
Use caution if you should attempt
to restart the engine after a crash
has occurred.
In many crashes severe enough to
inflate the airbag, windshields are
broken by vehicle deformation.
Additional windshield breakage may
also occur from the front outboard
passenger airbag.
.Airbags are designed to inflate only
once. After an airbag inflates, you
will need some new parts for the
airbag system. If you do not get
them, the airbag system will not be
there to help protect you in another
crash. A new system will include
airbag modules and possibly other
parts. The service manual for the
vehicle covers the need to replace
other parts.
.The vehicle has a crash sensing and
diagnostic module which records
information after a crash. See
Vehicle Data Recording and Privacy
0 410 and
Event Data Recorders 0411.
.Let only qualified technicians work
on the airbag system. Improper
service can mean that an airbag
system will not work properly. See
your dealer for service.
Passenger Sensing System
The vehicle has a passenger sensing
system for the front outboard
passenger position. The passenger
airbag status indicator will light on
the overhead console when the vehicle
is started.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
SEATS AND RESTRAINTS 55
The passenger sensing system is
designed to turn off the front
outboard passenger frontal airbag and
knee airbag if:
.The front outboard passenger seat
is unoccupied.
.The system determines an infant is
present in a child restraint.
.A front outboard passenger takes
his/her weight off of the seat for a
period of time.
When the passenger sensing system
has turned off the front outboard
passenger frontal airbag and knee
airbag, the OFF indicator will light and
stay lit as a reminder that the airbags
are off. See Passenger Airbag Status
Indicator 096.
The passenger sensing system is
designed to turn on the front
outboard passenger frontal airbag and
knee airbag, anytime the system
senses that a person of adult size is
sitting properly in the front outboard
passenger seat. When the passenger sensing system
has allowed the airbags to be enabled,
the ON indicator will light and stay lit
as a reminder that the airbags are
active.
For some children, including children
in child restraints, and for very small
adults, the passenger sensing system
may or may not turn off the front
outboard passenger frontal airbag and
knee airbag, depending upon the
person's seating posture and body
build. Everyone in the vehicle who has
outgrown child restraints should wear
a seat belt properly
—whether or not
there is an airbag for that person.
{Warning
If the airbag readiness light ever
comes on and stays on, it means
that something may be wrong with
the airbag system. To help avoid
injury to yourself or others, have
the vehicle serviced right away. See
Airbag Readiness Light 096 for more
information, including important
safety information.
If the On Indicator Is Lit for a
Child Restraint
The passenger sensing system is
designed to turn off the front
outboard passenger frontal airbag and
knee airbag, if the system determines
that an infant is present in a child
restraint. If a child restraint has been
installed and the ON indicator is lit:
1. Turn the vehicle off.
2. Remove the child restraint from the vehicle.
3. Remove any additional items from the seat such as blankets, cushions,
seat covers, seat heaters, or seat
massagers.
4. Reinstall the child restraint following the directions provided
by the child restraint manufacturer
and refer to Securing Child
Restraints (With the Seat Belt in the
Front Seat) 074 or
Securing Child Restraints (With the
Seat Belt in the Rear Seat) 072.
Make sure the seat belt retractor is
locked by pulling the shoulder belt
all the way out of the retractor
when installing the child restraint,

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
SEATS AND RESTRAINTS 57
{Warning
If the front outboard passenger
airbag is turned off for an
adult-sized occupant, the airbag will
not be able to inflate and help
protect that person in a crash,
resulting in an increased risk of
serious injury or even death. An
adult-sized occupant should not
ride in the front outboard passenger
seat, if the passenger airbag OFF
indicator is lit.
Additional Factors Affecting
System Operation
Seat belts help keep the passenger in
position on the seat during vehicle
maneuvers and braking, which helps
the passenger sensing system
maintain the passenger airbag status.
See“Seat Belts” and“Child Restraints”
in the Index for additional
information about the importance of
proper restraint use.
A thick layer of additional material,
such as a blanket or cushion,
or aftermarket equipment such as seat
covers, seat heaters, and seat massagers can affect how well the
passenger sensing system operates.
We recommend that you not use seat
covers or other aftermarket equipment
except when approved by GM for your
specific vehicle. See
Adding Equipment
to the Airbag-Equipped Vehicle 058 for
more information about modifications
that can affect how the system
operates.
The ON indicator may be lit if an
object, such as a briefcase, handbag,
grocery bag, laptop, or other electronic
device, is put on an unoccupied seat.
If this is not desired, remove the
object from the seat.{Warning
Stowing articles under the
passenger seat or between the
passenger seat cushion and
seatback may interfere with the
proper operation of the passenger
sensing system.
Servicing the
Airbag-Equipped Vehicle
Airbags affect how the vehicle should
be serviced. There are parts of the
airbag system in several places around
the vehicle. Your dealer and the
service manual have information
about servicing the vehicle and the
airbag system. To purchase a service
manual, see Publication Ordering
Information 0408.
{Warning
For up to 10 seconds after the
vehicle is turned off and the battery
is disconnected, an airbag can still
inflate during improper service. You
can be injured if you are close to an
airbag when it inflates. Avoid
yellow connectors. They are
probably part of the airbag system.
Be sure to follow proper service
procedures, and make sure the
person performing work for you is
qualified to do so.

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.