ECU CADILLAC CT4 2023 Repair Manual

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/5/22
Customer Information 497
electronic access, detecting
possible malicious activity in
related networks, and
responding to suspected
cybersecurity incidents in a
timely, coordinated and
effective manner. Security
incidents could impact your
safety or compromise your
private data. To minimize
security risks, please do not
connect your vehicle
electronic systems to
unauthorized devices or
connect your vehicle to any
unknown or untrusted
networks (such as Bluetooth,
WIFI or similar technology). In
the event you suspect any
security incident impacting
your data or the safe
operation of your vehicle,
please stop operating your
vehicle and contact your
dealer.Event Data Recorders
This vehicle is equipped with
an Event Data Recorder (EDR).
The main purpose of an EDR is
to record, in certain crash or
near crash-like situations, such
as an air bag deployment or
hitting a road obstacle, data
that will assist in
understanding how a vehicle’s
systems performed. The EDR
is designed to record data
related to vehicle dynamics
and safety systems for a short
period of time, typically
30 seconds or less. The EDR in
this vehicle is designed to
record such data as:
.How various systems in your
vehicle were operating;
.Whether or not the driver
and passenger safety belts
were buckled/fastened;
.How far (if at all) the driver
was depressing the
accelerator and/or brake
pedal; and,
.How fast the vehicle was
traveling.These data can help provide a
better understanding of the
circumstances in which
crashes and injuries occur.
Note
EDR data are recorded by
your vehicle only if a non-trivial
crash situation occurs; no data
are recorded by the EDR
under normal driving
conditions and no personal
data (e.g., name, gender, age,
and crash location) are
recorded. However, other
parties, such as law
enforcement, could combine
the EDR data with the type of
personally identifying data
routinely acquired during a
crash investigation.
To read data recorded by an
EDR, special equipment is
required, and access to the
vehicle or the EDR is needed.
In addition to the vehicle
manufacturer, other parties,
such as law enforcement, that
have the special equipment,

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
OnStar 499
OnStar
OnStar Overview
OnStar Overview . . . . . . . . . . 499
OnStar Services
Emergency . . . . . . . . . . . . . . . . . . 500
Security . . . . . . . . . . . . . . . . . . . . . . . 501
OnStar Additional
Information
OnStar AdditionalInformation . . . . . . . . . . . . . . . . . 501
OnStar Overview
=Voice Command Button
QBlue OnStar Button
>Red Emergency Button
This vehicle may be equipped
with a comprehensive,
in-vehicle system that can
connect to an OnStar Advisor
for Emergency, Security,
Navigation, Connections, and
Diagnostics Services. OnStar
services may require a paid
service plan and data plan.
OnStar requires the vehicle
battery and electrical system,
cellular service, and GPS
satellite signals to be available
and operating. OnStar acts as
a link to existing emergency
service providers. OnStar may
collect information about you and your vehicle, including
location information. See
OnStar User Terms, Privacy
Statement, and Software
Terms for more details
including system limitations at
www.onstar.com (U.S.) or
www.onstar.ca (Canada).
The OnStar system status
light is next to the OnStar
buttons. If the status light is:.Solid Green: System is ready.
.Flashing Green: On a call.
.Red: Indicates a problem.
.Off: System is off. PressQ
twice to speak with an
OnStar Advisor.
Press
Qor call
1-888-4ONSTAR
(1-888-466-7827) to speak to
an Advisor.
Functionality of the Voice
Command button may vary by
vehicle and region.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
500 OnStar
Press=to:
.Open the OnStar app on the
infotainment display.
If equipped, the infotainment
system has OnStar controls
in the embedded OnStar app
on the Home Page. Most
OnStar functions that can be
performed with the buttons
can be done using the app.
To open the app, touch the
OnStar icon on the Home
Page. App updates require a
corresponding service plan.
Features vary by region and
model. Features are subject
to change. For more
information, see
my.cadillac.com/learn or
press
Q.
Or
.Give OnStar Turn-by-Turn
Navigation voice commands.
.Obtain and customize the
Wi-Fi hotspot name or SSID
and password, if equipped. Press
Qto connect to an
Advisor to:
.Verify account information
or update contact
information.
.Get driving directions.
.Receive a Diagnostic check
of the vehicle's key
operating systems.
.Receive Roadside
Assistance.
.Manage Wi-Fi Settings,
if equipped.
Press
>to get a priority
connection to an OnStar
Advisor available 24/7 to:
.Get help for an emergency.
.Be a Good Samaritan or
respond to an AMBER Alert.
.Get assistance in severe
weather or other crisis
situations and find
evacuation routes.
OnStar Services
Emergency
Emergency Services require
an active safety and security
plan. With Automatic Crash
Response, built-in sensors can
automatically alert a specially
trained OnStar Advisor who is
immediately connected in to
the vehicle to help.
Press
>for a priority
connection to an OnStar
Advisor who can contact
emergency service providers,
direct them to your exact
location, and relay important
information.
With OnStar Crisis Assist,
specially trained Advisors are
available 24 hours a day,
7 days a week, to provide a
central point of contact,
assistance, and information
during a crisis.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
OnStar 501
With Roadside Assistance,
Advisors can locate a nearby
service provider to help with a
flat tire, a battery jump, or an
empty gas tank.
Security
If equipped, OnStar provides
these services:
.With Stolen Vehicle
Assistance, OnStar Advisors
can use GPS to pinpoint the
vehicle and help authorities
quickly recover it.
.With Remote Ignition Block,
if equipped, OnStar can
block the vehicle from being
restarted.
.With Stolen Vehicle
Slowdown, if equipped,
OnStar can work with law
enforcement to gradually
slow the vehicle down.
Theft Alarm Notification
If equipped, if the doors are
locked and the vehicle alarm
sounds, a notification by text,
e-mail, or phone call will besent. If the vehicle is stolen, an
OnStar Advisor can work with
authorities to recover the
vehicle.
OnStar Additional
Information
In-Vehicle Audio
Messages
Audio messages may play
important information at the
following times:
.Prior to vehicle purchase.
Press
Qto set up an
account.
.After change in ownership
and at 90 days.
Transferring Service
PressQto request account
transfer eligibility information.
The Advisor can cancel or
change account information.
Selling/Transferring the
Vehicle
Call 1-888-4ONSTAR
(1-888-466-7827) immediately
to terminate your OnStar or
connected services if the
vehicle is disposed of, sold,
transferred, or if the
lease ends.
Reactivation for
Subsequent Owners
PressQand follow the
prompts to speak to an
Advisor as soon as possible.
The Advisor will update vehicle
records and explain OnStar or
connected service options.
How OnStar Service
Works
Automatic Crash Response,
Emergency Services, Crisis
Assist, Stolen Vehicle
Assistance, Remote Services,
and Roadside Assistance are
available on most vehicles. Not
all OnStar services are
available everywhere or on all

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
504 OnStar
Unable to Connect to
OnStar Message
If there is limited cellular
coverage or the cellular
network has reached
maximum capacity, this
message may come on. Press
Qto try the call again or try
again after driving a few miles
into another cellular area.
Vehicle and Power Issues
OnStar services require a
vehicle electrical system,
wireless service, and GPS
satellite technologies to be
available and operating for
features to function properly.
These systems may not
operate if the battery is
discharged or disconnected.
Add-on Electrical
Equipment
The OnStar system is
integrated into the electrical
architecture of the vehicle. Do
not add any electrical equipment. See Add-On
Electrical Equipment
0366.
Added electrical equipment
may interfere with the
operation of the OnStar
system and cause it to not
operate.
Vehicle Software Updates
OnStar or GM may remotely
deliver software updates or
changes to the vehicle without
further notice or consent.
These updates or changes
may enhance or maintain
safety, security, or the
operation of the vehicle or the
vehicle systems. Software
updates or changes may
affect or erase data or
settings that are stored in the
vehicle, such as saved
navigation destinations or
pre-set radio stations. Neither
OnStar nor GM is responsible
for any affected or erased
data or settings. These
updates or changes may also
collect personal information.
Such collection is described in the OnStar privacy statement
or separately disclosed at the
time of installation. These
updates or changes may also
cause a system to
automatically communicate
with GM servers to collect
information about vehicle
system status, identify
whether updates or changes
are available, or deliver
updates or changes. An active
OnStar agreement constitutes
consent to these software
updates or changes and
agreement that either OnStar
or GM may remotely deliver
them to the vehicle.
Privacy
The complete OnStar Privacy
Statement may be found at
www.onstar.com (U.S.),
or www.onstar.ca (Canada).
We recommend that you
review it. If you have any
questions, call
1-888-4ONSTAR
(1-888-466-7827) or press
Q
to speak with an Advisor.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Connected Services 507
if equipped. After the call
ends, the navigation screen
will provide prompts to begin
driving directions. Routes that
are sent to the navigation
screen can only be canceled
through the navigation
system.
See www.onstar.com (U.S.) or
www.onstar.ca (Canada).
Connections
The following services help
with staying connected.
For coverage maps, see
www.onstar.com (U.S.) or
www.onstar.ca (Canada).
Ensuring Security
.Change the default
passwords for the Wi-Fi
hotspot and myCadillac
mobile app. Make these
passwords different from
each other and use a
combination of letters and
numbers to increase the
security.
.Change the default name of
the SSID (Service Set
Identifier). This is the
network name that is visible
to other wireless devices.
Choose a unique name and
avoid family names or vehicle
descriptions.
Wi-Fi Hotspot (If Equipped)
The vehicle may have a built-in
Wi-Fi hotspot that provides
access to the Internet and
web content at 4G LTE speed.
Up to seven mobile devices
can be connected. A data plan
is required. Use the in-vehicle
controls only when it is safe to
do so. 1. To retrieve Wi-Fi hotspot information, press
=to
open the OnStar app on
the infotainment display,
then select Wi-Fi Hotspot.
On some vehicles, touch
Wi-Fi or Wi-Fi Settings on
the screen.
2. The Wi-Fi settings will display the Wi-Fi hotspot
name (SSID), password, and on some vehicles, the
connection type (no
Internet connection, 3G,
4G, 4G LTE), and signal
quality (poor, good,
excellent). The LTE icon
shows connection to Wi-Fi.
It is possible that the icon
may not illuminate even
though the vehicle has an
active connection.
3. To change the SSID or password, press
Qor call
1-888-4ONSTAR to
connect with an Advisor.
On some vehicles, the SSID
and password can be
changed in the Wi-Fi
Hotspot menu.
After initial set-up, your
vehicle’s Wi-Fi hotspot will
connect automatically to your
mobile devices. Manage data
usage by turning Wi-Fi on or
off on your mobile device, by
using the myCadillac mobile
app, or by contacting an
OnStar Advisor. On some

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/10/22
INDEX 509
IndexA
Accessories andModifications . . . . . . . . . . . . . . . . 370
Accessory Power . . . . . . . . . . . .267
Active Rev Match . . . . . . . . . . . . . . . . . . . 285
Adaptive Cruise Control . . . . . . . . . . . . . . 304
Add-On Electrical Equipment . . . . . . . . . . . . . . . . . . . 366
Additional OnStar Information . . . . . . . . 501
Adjustments Lumbar, Front Seats . . . . . . . 40
Thigh Support . . . . . . . . . . . . . . . . 39
Agreements Trademarks andLicense . . . . . . . . . . . . . . . . . . . . . . 215
Air
Cleaner/Filter, Engine . . . . 384
Conditioning . . . . . . . . . . . . . . . . 225
Filter Life System . . . . . . . . . 383
Filter, PassengerCompartment . . . . . . . . . . . . . . 231
Vents . . . . . . . . . . . . . . . . . . . . . . . . . . 230
Airbag System . . . . . . . . . . . . . . . . . 59 Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 Airbag System (cont'd)
How Does an Airbag
Restrain? . . . . . . . . . . . . . . . . . . . . . 64
Passenger Sensing System . . . . . . . . . . . . . . . . . . . . . . . . 66
What Makes an Airbag Inflate? . . . . . . . . . . . . . . . . . . . . . . . . 63
What Will You See after an Airbag
Inflates? . . . . . . . . . . . . . . . . . . . . . . 64
When Should an Airbag Inflate? . . . . . . . . . . . . . . . . . . . . . . . . 62
Where Are the Airbags? . . . . . . . . . . . . . . . . . . . . . . . 61
Airbags Adding Equipment to
the Vehicle . . . . . . . . . . . . . . . . . . . 70
Passenger Status Indicator . . . . . . . . . . . . . . . . . . . . . . 117
Readiness Light . . . . . . . . . . . . . 116
Replacing System Parts after a Crash . . . . . . . 72
Servicing Airbag-Equipped
Vehicles . . . . . . . . . . . . . . . . . . . . . . 70
Alarm
Vehicle Security . . . . . . . . . . . . . 24

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/10/22
INDEX 511
Bulb Replacement (cont'd)High Intensity
Discharge (HID)
Lighting . . . . . . . . . . . . . . . . . . . . . 403
Buying New Tires . . . . . . . . . . . . 432
C
Calibration Compass . . . . . . . . . . . . . . . . . . . . . . 101
California Perchlorate MaterialsRequirements . . . . . . . . . . . . . 370
California Proposition 65 Warning . . . . . . . . . . . . . . . . 1, 447
Camera Rear Vision (RVC) . . . . . . . . . 335
Canadian Vehicle Owners . . . . 2
Capacities and
Specifications . . . . . . . . . . . . . . . 480
Carbon Monoxide Engine Exhaust . . . . . . . . . . . . . 271
Trunk . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Winter Driving . . . . . . . . . . . . . . 253
Cargo Management System . . . . . . 96
Tie-Downs . . . . . . . . . . . . . . . . . . . . . 96
Caution, Danger, and Warning . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Center Console
Storage . . . . . . . . . . . . . . . . . . . . . . . . 95
Chains, Tire . . . . . . . . . . . . . . . . . . . 437
Charging System Light . . . . . . . . . . . . . . . . . 117
Wireless . . . . . . . . . . . . . . . . . . . . . . . 102
Check Engine Light
(Malfunction Indicator) . . . . .118
Child Restraints Infants and YoungChildren . . . . . . . . . . . . . . . . . . . . . . . 74
Lower Anchors and Tethers for Children . . . . . . 80
Older Children . . . . . . . . . . . . . . . . 72
Securing . . . . . . . . . . . . . . . . . . 88, 90
Systems . . . . . . . . . . . . . . . . . . . . . . . . 77
Child Safety Locks . . . . . . . . . . . . 22
Circuit Breakers . . . . . . . . . . . . . 406
Cleaning Exterior Care . . . . . . . . . . . . . . . 455
Interior Care . . . . . . . . . . . . . . . . . 461
Climate Control Systems Dual Automatic . . . . . . . . . . . . . 225
Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Cluster, Instrument . . . 106, 108
Clutch, Hydraulic . . . . . . . . . . . . 383
Collision Damage Repair . . . 491 Compartments
Storage . . . . . . . . . . . . . . . . . . . . . . . . 94
Compass . . . . . . . . . . . . . . . . . . . . . . . . 101
Competitive Driving Mode . . . . . . . . . . . . . . . . 298
Composite Materials . . . . . . . 260
Compressor Kit, Tire Sealant . . . . . . . . . . . . . . . . . . . . . . . . 439
Connected Services Connections . . . . . . . . . . . . . . . . 507
Diagnostics . . . . . . . . . . . . . . . . . . 508
Navigation . . . . . . . . . . . . . . . . . . . 506
Connections Connected Services . . . . . . 507
Control Traction and
Electronic Stability . . . . . . 290
Control of a Vehicle . . . . . . . . 235
Controls Steering Wheel . . . . . . . . . . . . . 158
Convex Mirrors . . . . . . . . . . . . . . . . 28
Coolant
EngineTemperature
Gauge . . . . . . . . . . . . . . . . . . . 114, 115
Engine Temperature Warning Light . . . . . . . . . . . . . . 124

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/10/22
512 INDEX
Cooling . . . . . . . . . . . . . . . . . . . . . . . . . 225
Cooling System . . . . . . . . . . . . . . 386
Cornering Lamps . . . . . . . . . . . . . 149
Courtesy Lamps . . . . . . . . . . . . . . 150
CourtesyTransportation
Program . . . . . . . . . . . . . . . . . . . . . . 490
Coverage Explanations . . . . . 185
Cruise Control . . . . . . . . . . . . . . . . . 301 Adaptive . . . . . . . . . . . . . . . . . . . . . 304
Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
Super . . . . . . . . . . . . . . . . . . . . . . . . . . 316
Cupholders . . . . . . . . . . . . . . . . . . . . . . 94
Customer Assistance Offices . . . . . . . . . . . . . . . . . . . . . . . . 485
Text Telephone (TTY)Users . . . . . . . . . . . . . . . . . . . . . . . . 486
Customer Information Publications OrderingInformation . . . . . . . . . . . . . . . . 494
Customer Satisfaction
Procedure . . . . . . . . . . . . . . . . . . . 483
Cybersecurity . . . . . . . . . . . . . . . . 496D
Damage Repair, Collision . . . . . . . . . . . . . . . . . . . . . . . . 491
Danger, Warning, and Caution . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Dashboard . . . . . . . . . . . . . . . . . . . . . . . . . 5
Data Collection Infotainment System . . . . . 498
OnStar . . . . . . . . . . . . . . . . . . . . . . . . 498
Data Recorder
Performance . . . . . . . . . . . . . . . . . 192
Data Recorders, Event . . . . 497
Database Coverage Explanations . . . . . . . . . . . . . . . . . 185
Daytime Running Lamps (DRL) . . . . . . . . . . . . . . . . . 147
Defensive Driving . . . . . . . . . . . . 235
Delayed Locking . . . . . . . . . . . . . . . 20
Destination . . . . . . . . . . . . . . . . . . . . . 176
Diagnostics Connected Services . . . . . . 508
Differential, Limited-Slip . . . . 301
Disabled Vehicle Transporting . . . . . . . . . 450, 452
Distracted Driving . . . . . . . . . . . 234
Dome Lamps . . . . . . . . . . . . . . . . . . . 150 Door
Ajar Light . . . . . . . . . . . . . . . . . . . . . 129
Delayed Locking . . . . . . . . . . . . . 20
Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Power Locks . . . . . . . . . . . . . . . . . . 20
Drive Belt Routing, Engine . . . . . . . . . . . . . . . . . . . . . . . . . 482
Drive Systems All-Wheel Drive . . . . . . 286, 400
Driver Assistance Systems . . . . . . 333
Information
Center (DIC) . . . . . . . . . . 129, 132
Mode Control . . . . . . . . . . . . . . . 292
Mode Control Light . . . . . . . . 125
Teen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211
Driving Assistance Systems . . . . . . 342
Better Fuel Economy . . . . . 234
Characteristics andTowing Tips . . . . . . . . . . . . . . . 358
Competitive . . . . . . . . . . . . . . . . . 298
Defensive . . . . . . . . . . . . . . . . . . . . 235
Distracted . . . . . . . . . . . . . . . . . . . 234
Hill and Mountain Roads . . . . . . . . . . . . . . . . . . . . . . . 252
If the Vehicle is Stuck . . . . 255
Impaired . . . . . . . . . . . . . . . . . . . . . . 235

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/10/22
516 INDEX
LATCH, Lower Anchorsand Tethers for
Children . . . . . . . . . . . . . . . . . . . . . . . . . 80
LED Lighting . . . . . . . . . . . . . . . . . . 403
Lighting Entry . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
Exit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
Illumination Control . . . . . . . . 150
LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . 403
Lights Airbag Readiness . . . . . . . . . . . 116
Antilock Brake System
(ABS) Warning . . . . . . . . . . . . . . 121
Automatic Emergency Braking (AEB)
Disabled . . . . . . . . . . . . . . . . . . . . . 123
Automatic Vehicle Hold . . . . . . . . . . . . . . . . 122
Brake System Warning . . . . . . . . . . . . . . . . . . . . . 120
Charging System . . . . . . . . . . . . 117
Check Engine
(Malfunction
Indicator) . . . . . . . . . . . . . . . . . . . . 118
Cruise Control Light . . . . . . . 128
Door Ajar . . . . . . . . . . . . . . . . . . . . . . 129
Driver Mode Control . . . . . . . 125
Electric Parking Brake . . . . . 121 Lights (cont'd)
Engine Coolant
Temperature
Warning . . . . . . . . . . . . . . . . . . . . . 124
Engine Oil Pressure . . . . . . . . 127
Gauges and Indicators . . . . 105
High-Beam On . . . . . . . . . . . . . . . 128
Lane Keep Assist . . . . . . . . . . . 122
Low Fuel Warning . . . . . . . . . . 127
Performance Shifting . . . . . 122
Seat Belt Reminders . . . . . . 115
Security . . . . . . . . . . . . . . . . . . . . . . . 128
Service Electric Parking Brake . . . . . . . . . . . . . . . 121
StabiliTrak OFF . . . . . . . . . . . . . 124
Tire Pressure . . . . . . . . . . . . . . . . 126
Traction Control System
(TCS)/StabiliTrak . . . . . . . . . . 124
Traction Off . . . . . . . . . . . . . . . . . . 123
Limited-Slip Differential . . . . 301
Locks
Automatic Door . . . . . . . . . . . . . . . 21
Delayed Locking . . . . . . . . . . . . . 20
Door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Lockout Protection . . . . . . . . . . 21
Power Door . . . . . . . . . . . . . . . . . . . 20
Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Loss of Control . . . . . . . . . . . . . . .237
Low Fuel Warning Light . . . . 127
Low-Profile Tires . . . . . . . . . . . . . 416
Lower Anchors and
Tethers for Children
(LATCH System) . . . . . . . . . . . . . 80
Lumbar Adjustment . . . . . . . . . . 40
Front Seats . . . . . . . . . . . . . . . . . . . 40
M
MaintenanceRecords . . . . . . . . . . . . . . . . . . . . . . . 477
Maintenance Schedule . . . . 469 Recommended Fluidsand Lubricants . . . . . . . . . . . 474
Malfunction Indicator Lamp . . . . . . . . . . . . . . .118
Manual Mode . . . . . . . . . . . . . . . . . . . . 280, 281
Transmission . . . . . . . . . . . . . . . 283
Transmission Fluid . . . . . . . . 382
Map Data Updates . . . . . . . . . . . 184
Maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
Massage Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Matching
Active Rev . . . . . . . . . . . . . . . . . . . 285