maintenance CADILLAC CT4 2021 Owner's Manual

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
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
INSTRUMENTS AND CONTROLS 91
.Info Tiles Selection/Trip Computer/
Maintenance: The selected Driver
Information Center (DIC) displays
can be viewed. SeeDriver
Information Center (DIC) (Base Level)
0 107 or
Driver Information Center (DIC)
(Uplevel) 0110.
.Performance (If Equipped)
.Driver Assistance
.Audio
.Phone
.Navigation
.Options
.Simplify
Performance
If equipped, press the thumbwheel to
enter the Performance menu. Scroll
through the available items.
Friction Bubble : A four quadrant
visual display, indicative of the four
corners of the car, with a “bubble”
showing where the most inertia is
being exerted on the vehicle. Performance Timer :
Press the
thumbwheel to enter the setup menu.
Use the thumbwheel to scroll to select
the desired speed segment, then press
the thumbwheel to enter the
submenu. Use the thumbwheel to
confirm the speed segment selection
or to reset the best time for that
segment. On the next acceleration, the
performance timer will record the
time. Pressing the thumbwheel while
the timer is running will cancel the
timer if done before reaching the end
of the segment.
Lap Timer : Press the thumbwheel
when Lap Timer is displayed to start,
stop, or reset the lap timer. Press the
thumbwheel while the Lap Timer page
is active to start the timer. If the lap
timer is active, pressing the
thumbwheel will stop the current lap
timer and start a new lap. Pressing the
thumbwheel within 10 seconds after
completing the last lap (Stop Lap
Timer option is displayed), the Lap
Timer will stop. Press the thumbwheel
after the lap timer is stopped to reset
the timer, or to view the lap history.
A maximum of 16 laps will be stored. Launch Control :
If equipped, the
Launch Control display allows the
driver to adjust the parameters of the
Launch Control System. See Track
Events and Competitive Driving (V-Series
Only) 0207.
Audio
In the Audio menu, use the
thumbwheel to scroll through audio
presets.
Phone
In the Phone menu, if there is no
active phone call, view recent calls,
or scroll through contacts. If there is
an active call, mute the phone or
switch to handset operation.
Navigation
If there is an active route, press the
thumbwheel to cancel or resume route
guidance, or turn the voice prompts
on or off.
Options
Use the thumbwheel to scroll through
items in the Options menu.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
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98 INSTRUMENTS AND CONTROLS
require service. The light should come
on to show that it is working when
the ignition is in Service Mode. See
Ignition Positions0219.
Malfunctions are often indicated by
the system before any problem is
noticeable. Being aware of the light
and seeking service promptly when it
comes on may prevent damage.
Caution
If the vehicle is driven continually
with this light on, the emission
control system may not work as
well, the fuel economy may be
lower, and the vehicle may not run
smoothly. This could lead to costly
repairs that might not be covered
by the vehicle warranty.
Caution
Modifications to the engine,
transmission, exhaust, intake,
or fuel system, or the use of
replacement tires that do not meet
the original tire specifications, can
cause this light to come on. This
could lead to costly repairs not
covered by the vehicle warranty.
This could also affect the vehicle’s
ability to pass an Emissions
Inspection/Maintenance test. See
Accessories and Modifications 0306.
If the light is f lashing : A
malfunction has been detected that
could damage the emission control
system and increase vehicle
emissions. Diagnosis and service may
be required.
To help prevent damage, reduce
vehicle speed and avoid hard
accelerations and uphill grades.
If towing a trailer, reduce the amount
of cargo being hauled as soon as
possible. If the light continues to flash, find a
safe place to park. Turn the vehicle off
and wait at least 10 seconds before
restarting the engine. If the light is
still flashing, follow the previous
guidelines and see your dealer for
service as soon as possible.
If the light is on steady :
A
malfunction has been detected.
Diagnosis and service may be
required.
Check the following:
.If fuel has been added to the vehicle
using the capless fuel funnel
adapter, make sure that it has been
removed. See “Filling the Tank with
a Portable Gas Can ”under Filling the
Tank 0295. The diagnostic system
can detect if the adapter has been
left installed in the vehicle, allowing
fuel to evaporate into the
atmosphere. A few driving trips with
the adapter removed may turn off
the light.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
INSTRUMENTS AND CONTROLS 99
.Poor fuel quality can cause
inefficient engine operation and
poor driveability, which may go
away once the engine is warmed up.
If this occurs, change the fuel
brand. It may require at least one
full tank of the proper fuel to turn
the light off. SeeRecommended Fuel
(LSY 2.0L L4 Turbo Engine) 0293 or
Recommended Fuel (L3B 2.7L L4
Turbo Engine) 0294.
If the light remains on, see your
dealer.
Emissions Inspection and
Maintenance Programs
If the vehicle requires an Emissions
Inspection/Maintenance test, the test
equipment will likely connect to the
vehicle's Data Link Connector (DLC).
The DLC is under the instrument
panel to the left of the steering wheel.
Connecting devices that are not used
to perform an Emissions Inspection/
Maintenance test or to service the
vehicle may affect vehicle operation.
See Add-On Electrical Equipment 0303.
See your dealer if assistance is needed.
The vehicle may not pass
inspection if:
.The light is on when the engine is
running.
.The light does not come on when
the ignition is in Service Mode.
.Critical emission control systems
have not been completely
diagnosed. If this happens, the
vehicle would not be ready for
inspection and might require
several days of routine driving
before the system is ready for
inspection. This can happen if the
12-volt battery has recently been
replaced or run down, or if the
vehicle has been recently serviced.
See your dealer if the vehicle will not
pass or cannot be made ready for
the test.
Brake System Warning
Light
MetricEnglish
This light should come on briefly
when the vehicle is turned on. If it
does not come on then, have it fixed
so it will be ready to warn you if there
is a problem.
If the light comes on and stays on at
start up, there is a brake problem.
Have the brake system inspected
right away.
If the light comes on while driving,
pull off the road and stop carefully.
The brake system has electric brake
boost. Vehicle speed may be limited
when the brake system warning light
comes on. The brake pedal might be
harder to push, or the brake pedal
may go closer to the floor. It could

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
104 INSTRUMENTS AND CONTROLS
This light comes on when Snow/Ice
Mode is selected.
This light comes on when Track Mode
is selected. SeeDriver Mode Control
0 241.
This light comes on when V Mode is
selected. See Driver Mode Control
0 241.
This light comes on when My Mode is
selected. See Driver Mode Control
0 241.
Tire Pressure Light
For vehicles with the Tire Pressure
Monitor System (TPMS), this light
comes on briefly when the engine is
started. It provides information about
tire pressures and the TPMS.
When the Light Is On Steady
This indicates that one or more of the
tires are significantly underinflated.
A Driver Information Center (DIC) tire
pressure message may also display.
Stop as soon as possible, and inflate the tires to the pressure value shown
on the Tire and Loading Information
label. See
Tire Pressure 0346.
When the Light Flashes First and
Then Is On Steady
If the light flashes for about a minute
and then stays on, there may be a
problem with the TPMS. If the
problem is not corrected, the light will
come on at every ignition cycle. See
Tire Pressure Monitor Operation 0349.
Engine Oil Pressure Light
Caution
Lack of proper engine oil
maintenance can damage the
engine. Driving with the engine oil
low can also damage the engine.
The repairs would not be covered
by the vehicle warranty. Check the
oil level as soon as possible. Add oil
if required, but if the oil level is
within the operating range and the
oil pressure is still low, have the
vehicle serviced. Always follow the
maintenance schedule for changing
engine oil.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
108 INSTRUMENTS AND CONTROLS
While in the Info Page Options menu,
the info pages can be restored to the
default factory settings by pressing
and holding
Ron the left steering
wheel controls and the thumbwheel
on the right steering wheel controls at
the same time.
Speed : Shows the vehicle speed in
either kilometers per hour (km/h) or
miles per hour (mph).
Trip 1 or Trip 2 and Average Fuel
Economy : The Trip display shows the
current distance traveled, in either
kilometers (km) or miles (mi), since
the trip odometer was last reset. The
trip odometer can be reset by pressing
Vand selecting yes or no while this
display is active.
The Average Fuel Economy display
shows the approximate average liters
per 100 kilometers (L/100 km) or
miles per gallon (mpg). This number
is calculated based on the number of
L/100 km (mpg) recorded since the
last time this menu item was reset.
This number reflects only the
approximate average fuel economy
that the vehicle has right now, and
will change as driving conditions change. The Average Fuel Economy
can be reset by pressing
Vand
selecting yes or no while this display
is active.
Fuel Range : Shows the approximate
distance the vehicle can be driven
without refueling. LOW will be
displayed when the vehicle is low on
fuel. The fuel range estimate is based
on an average of the vehicle's fuel
economy over recent driving history
and the amount of fuel remaining in
the fuel tank.
Oil Life : Shows an estimate of the
oil's remaining useful life.
If REMAINING OIL LIFE 99% is
displayed, that means 99% of the
current oil life remains.
When the remaining oil life is low, the
CHANGE ENGINE OIL SOON message
will appear on the display. The oil
should be changed as soon as
possible. See Engine Oil0312. In
addition to the engine oil life system
monitoring the oil life, additional
maintenance is recommended. See
Maintenance Schedule 0380. The Oil Life display must be reset
after each oil change. It will not reset
itself. Do not reset the Oil Life display
accidentally at any time other than
when the oil has just been changed.
It cannot be reset accurately until the
next oil change. See
Engine Oil Life
System 0314.
Air Filter Life : If equipped, Shows an
estimate of the engine air filter’s
remaining useful life and the state of
the system. Engine Air Filter Life 95%
means 95% of the current air filter life
remains. Messages will display based
on the engine air filter life and the
state of the system. When the
REPLACE AT NEXT OIL CHANGE
message displays, the engine air filter
should be replaced at the time of the
next oil change. When the REPLACE
SOON message displays, the engine air
filter should be replaced at the earliest
convenience.
The Air Filter Life display must be
reset after the engine air filter
replacement. To reset, see Engine Air
Filter Life System 0315.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
112 INSTRUMENTS AND CONTROLS
Current Drive Cycle :Displays
information in relation to the current
drive cycle including Distance
Traveled, Average Fuel Economy, and
the Total Time. They will reset after
the drive cycle is completed.
Driver Assistance : If equipped,
displays the states of all active safety
systems.
Oil Life : Displays an estimate of the
oil's remaining useful life.
If REMAINING OIL LIFE 99% is
displayed, that means 99% of the
current oil life remains.
When the remaining oil life is low, the
CHANGE ENGINE OIL SOON message
will appear on the display. The oil
should be changed as soon as
possible. See Engine Oil0312. In
addition to the engine oil life system
monitoring the oil life, additional
maintenance is recommended in the
Maintenance Schedule. See the
Maintenance Schedule booklet..
The Oil Life display must be reset
after each oil change. It will not reset
itself. Do not reset the Oil Life display
accidentally at any time other than
when the oil has just been changed. It cannot be reset accurately until the
next oil change. See
Engine Oil Life
System 0314.
Air Filter Life : If equipped, shows an
estimate of the engine air filter’s
remaining useful life and the state of
the system. Engine Air Filter Life 95%
means 95% of the current air filter life
remains. Messages will display based
on the engine air filter life and the
state of the system. When the
REPLACE AT NEXT OIL CHANGE
message displays, the engine air filter
should be replaced at the time of the
next oil change. When the REPLACE
NOW message displays, the engine air
filter should be replaced as soon as
possible.
Engine Hours : Displays the total
number of hours the engine has run.
The display also shows the engine idle
hours.
Lifetime Revs : The display also
shows total engine revolutions divided
by 10,000.
Brake Pad Life : If equipped, This
displays an estimate of the remaining
life of the front and rear brake pads.
Messages will display based on brake pad wear and the state of the system.
Reset the Brake Pad Life display after
replacing the brake pads. See
Brake
Pad Life System (If Equipped) 0324.
Head-Up Display (HUD)
{Warning
If the HUD image is too bright or
too high in your field of view, it
may take you more time to see
things you need to see when it is
dark outside. Be sure to keep the
HUD image dim and placed low in
your field of view.
If equipped with HUD, some
information concerning the operation
of the vehicle is projected onto the
windshield. The information is
projected through the HUD lens on
the driver side of the instrument
panel and focused out toward the
front of the vehicle.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
196 CLIMATE CONTROLS
Climate Controls
Climate Control Systems
Dual Automatic Climate ControlSystem . . . . . . . . . . . . . . . . . . . . . . . . . . 196
Air Vents
Air Vents . . . . . . . . . . . . . . . . . . . . . . . . . . 200
Maintenance
Passenger Compartment AirFilter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
Climate Control Systems
Dual Automatic Climate Control System
The climate control buttons on the center stack and on the climate control
display are used to adjust the heating, cooling, and ventilation system. Center
Stack Climate Controls
1. ON/OFF (Power)
2. AUTO (Automatic Operation)
3. Air Delivery Mode Control
4. Driver Temperature Controls
5. Fan Control
6. Passenger Temperature Controls7. A/C (Air Conditioning)
8. Recirculation
9. SYNC (Synchronized Temperature)
10. Defrost
11. Rear Window Defogger

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2021 - CRC - 11/23/20
CLIMATE CONTROLS 201
Move the slider knobs to change the
direction of or to close off the airf low.
Operation Tips
.Clear away any ice, snow, or leaves
from air inlets at the base of the
windshield that could block the
flow of air into the vehicle.
.Clear snow off the hood to improve
visibility and help decrease moisture
drawn into the vehicle.
.Keep the path under the front seats
clear of objects to help circulate the
air inside of the vehicle more
effectively.
.Use of non-GM approved hood
deflectors can adversely affect the
performance of the system. Check
with your dealer before adding
equipment to the outside of the
vehicle.
.Do not attach any devices to the air
vent slats. This restricts airf low and
may cause damage to the air vents.
Maintenance
Passenger Compartment
Air Filter
The filter reduces dust, pollen, and
other airborne irritants from outside
air that is pulled into the vehicle. The
filter should be replaced as part of
routine scheduled maintenance. See
Maintenance Schedule0380.
See your dealer regarding replacement
of the filter.
Service
All vehicles have a label underhood
that identifies the refrigerant used in
the vehicle. The refrigerant system
should only be serviced by trained and
certified technicians. The air
conditioning evaporator should never
be repaired or replaced by one from a
salvage vehicle. It should only be
replaced by a new evaporator to
ensure proper and safe operation. During service, all refrigerants should
be reclaimed with proper equipment.
Venting refrigerants directly to the
atmosphere is harmful to the
environment and may also create
unsafe conditions based on inhalation,
combustion, frostbite, or other
health-based concerns.
The air conditioning system requires
periodic maintenance. See
Maintenance Schedule
0380.