2021 CADILLAC CT4 Aftermarket

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.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
INFOTAINMENT SYSTEM 135
.Set up the audio by presetting
favorite stations, setting the tone,
and adjusting the speakers.
.Set up phone numbers in advance
so they can be called easily by
pressing a single control or by using
a single voice command.
See Distracted Driving 0203.
Active Noise Cancellation (ANC)
If equipped, ANC reduces engine noise
in the vehicle’s interior. ANC requires
the factory-installed audio system,
radio, speakers, amplifier (if
equipped), induction system, and
exhaust system to work properly.
Deactivation is required by your dealer
if related aftermarket equipment is
installed.
Overview
Infotainment System
The infotainment system is controlled
by using the infotainment display,
controls on the center console,
steering wheel controls, and voice
recognition.
1.O(Power and Mute) Knob
.When off, press theOknob to
turn the system on.
.Turn to decrease or increase
the volume.
.Press and hold to turn the
power off.
.Press to mute/unmute the
system when on.
.When the power is on and the
system is not muted, a quick
status pane will display when
the knob is pressed. Pressing
the knob will mute the system
and trigger this pane to show a long press is required to
actually power down the
system.
2.VKnob
.Turn to highlight a feature.
Press to activate the
highlighted feature.
3.{(Home Page)
.Press to go to the Home Page.
See
“Home Page ”later in this
section.
Press to exit Android Auto or
Apple CarPlay. To enter back
into Android Auto or Apple
CarPlay, press and hold. See
Apple CarPlay and Android
Auto 0174.
4.W(Near Field Communication)
.See “Near Field
Communication (NFC)” under
Bluetooth (Overview) 0169 or
Bluetooth (Pairing and Using a
Phone) 0170

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
INFOTAINMENT SYSTEM 175
and plugging into a USB data port.
For best performance, it is highly
recommended to use the device’s
factory-provided USB cable, which
should be replaced after significant
wear to maintain connection
quality. Aftermarket or third-party
cables may not work.
3. When the phone is first connected to activate Apple CarPlay or
Android Auto, accept the terms
and conditions on both the
infotainment system and the
phone.
4. Follow the instructions on the phone.
The Android Auto and Apple CarPlay
icons on the Home Page will
illuminate depending on the
smartphone. Android Auto and/or
Apple CarPlay may automatically
launch upon USB connection. If not,
touch the Android Auto or Apple
CarPlay icon on the Home Page to
launch.
Press
{on the center stack to return
to the Home Page. For Wireless Phone Projection
Verify your phone is wireless
compatible by visiting the Google
Android Auto or Apple CarPlay
support page.
1. Download the Android Auto app to your smartphone from the Google
Play store. There is no app required
for Apple CarPlay.
2. For first time connection, there are two ways to set up wireless
projection:
.Connect your Android phone or
Apple iPhone by using the
factory-provided phone USB
cable and plugging into a USB
data port. For best performance,
it is highly recommended to use
the device’s factory-provided
USB cable, which should be
replaced after significant wear
to maintain connection quality.
Aftermarket or third-party
cables may not work.
.Connecting the phone over
Bluetooth. See Bluetooth
(Overview) 0169 or
Bluetooth (Pairing and Using a
Phone) 0170. 3. Make sure WiFi is turned on the
phone for wireless projection
to work.
4. When the phone is first connected to activate Apple CarPlay or
Android Auto, agree to the terms
and conditions on both the
infotainment system and the
phone.
5. Follow the instructions on the phone.
The Android Auto and Apple CarPlay
icons on the Home Page will
illuminate depending on the
smartphone. Android Auto and/or
Apple CarPlay may automatically
launch upon wireless connection.
If not, touch the Android Auto or
Apple CarPlay icon on the Home Page
to launch.
To disconnect the phones wireless
projection: 1. Select Settings from the Home Page.
2. Select Phones
3. Touch
4next to the phone to be
disconnected.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
DRIVING AND OPERATING 227
Warning (Continued)
.The exhaust smells or sounds
strange or different.
.The exhaust system leaks due to
corrosion or damage.
.The vehicle exhaust system has
been modified, damaged,
or improperly repaired.
.There are holes or openings in
the vehicle body from damage or
aftermarket modifications that
are not completely sealed.
If unusual fumes are detected or if
it is suspected that exhaust is
coming into the vehicle:
.Drive it only with the windows
completely down.
.Have the vehicle repaired
immediately.
Never park the vehicle with the
engine running in an enclosed area
such as a garage or a building that
has no fresh air ventilation.
Running the Vehicle While
Parked
It is better not to park with the engine
running. See Engine Exhaust 0226.
If the vehicle is left with the engine
running, follow the proper steps to be
sure the vehicle will not move. See
Shifting Into Park (Mechanical Shifter)
0 223 or
Shifting Into Park (Electronic Shifter)
0 224 and
Electric Parking Brake 0237.
Automatic Transmission
Automatic Transmission
(Mechanical Shifter)
There are several different positions
for the shift lever.
P : This position locks the drive
wheels. Use P (Park) when starting the
vehicle to ensure the vehicle does
not move.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
DRIVING AND OPERATING 303
Trailer Brakes
Loaded trailers over 450 kg (1,000 lb)
must be equipped with brake systems
and with brakes for each axle. Trailer
braking equipment conforming to
Canadian Standards Association (CSA)
requirement CAN3-D313, or its
equivalent, is recommended.
State or local regulations may require
trailers to have their own braking
system if the loaded weight of the
trailer exceeds certain minimums that
can vary from state to state. Read and
follow the instructions for the trailer
brakes so they are installed, adjusted,
and maintained properly. Never
attempt to tap into your vehicle's
hydraulic brake system. If you do,
both the vehicle anti-lock brakes and
the trailer brakes may not function,
which could result in a crash.
Trailer Lamps
Always check all trailer lamps are
working at the beginning of each trip,
and periodically on longer trips.
Turn Signals When Towing a
Trailer
When properly connected, the trailer
turn signals will illuminate to indicate
the vehicle is turning, changing lanes,
or stopping. When towing a trailer,
the arrows on the instrument cluster
will illuminate even if the trailer is not
properly connected or the bulbs are
burned out.
Conversions and
Add-Ons
Add-On Electrical
Equipment
{Warning
The Data Link Connector (DLC) is
used for vehicle service and
Emission Inspection/Maintenance
testing. SeeMalfunction Indicator
Lamp (Check Engine Light) 097.
A device connected to the DLC —
such as an aftermarket fleet or
driver-behavior tracking device —
(Continued)
Warning (Continued)
may interfere with vehicle systems.
This could affect vehicle operation
and cause a crash. Such devices
may also access information stored
in the vehicle’s systems.
Caution
Some electrical equipment can
damage the vehicle or cause
components to not work and would
not be covered by the vehicle
warranty. Always check with your
dealer before adding electrical
equipment.
Add-on equipment can drain the
vehicle's 12-volt battery, even if the
vehicle is not operating.
The vehicle has an airbag system.
Before attempting to add anything
electrical to the vehicle, see Servicing
the Airbag-Equipped Vehicle 057 and
Adding Equipment to the
Airbag-Equipped Vehicle 058.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
VEHICLE CARE 325
How to Disable the Brake Pad
Life System
The brake pad life system can be
turned off. This may be necessary if
aftermarket brake pads without wear
sensors are installed. When the
system is turned off, the front and
rear brake pad life percentages will
not display. However, the built-in wear
indicators that make a high-pitched
warning sound when the brake pads
are worn can still determine when the
pads should be replaced. SeeBrakes
0 323.
To turn off the brake pad life system: 1. Display Brake Pad Life on the DIC. See Driver Information Center (DIC)
(Base Level) 0107 or
Driver Information Center (DIC)
(Uplevel) 0110.
2. Select DISABLE.
To turn the brake pad life system back
on, follow the above steps but select
ENABLE in Step 2.
Brake Fluid
The brake master cylinder reservoir is
filled with GM approved DOT 4 brake
fluid as indicated on the reservoir cap.
See Engine Compartment Overview
0 309 for the location of the reservoir.
Checking Brake Fluid
With the vehicle in P (Park) on a level
surface, the brake fluid level should be
between the minimum and maximum
marks on the brake fluid reservoir.
There are only two reasons why the
brake fluid level in the reservoir may
go down:
.Normal brake lining wear. When
new linings are installed, the fluid
level goes back up.
.A fluid leak in the brake hydraulic
system. Have the brake hydraulic
system fixed. With a leak, the
brakes will not work well. Always clean the brake fluid reservoir
cap and the area around the cap
before removing it.
Do not top off the brake fluid. Adding
fluid does not correct a leak. If fluid is
added when the linings are worn,
there will be too much fluid when
new brake linings are installed. Add or
remove fluid, as necessary, only when
work is done on the brake hydraulic
system.
{Warning
If too much brake fluid is added, it
can spill on the engine and burn,
if the engine is hot enough. You or
others could be burned, and the
vehicle could be damaged. Add
brake fluid only when work is done
on the brake hydraulic system.
When the brake fluid falls to a low
level, the brake warning light comes
on. See Brake System Warning Light
0 99.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
VEHICLE CARE 329
Caution
Do not apply tape or hang any
objects from gas struts. Also do not
push down or pull on gas struts.
This may cause damage to the
vehicle.
See Maintenance Schedule 0380.
Hood
Trunk
Liftgate
Headlamp Aiming
Front Headlamp Aiming
Headlamp aim has been preset and
should need no further adjustment.
If the vehicle is damaged in a crash,
the headlamp aim may be affected.
If adjustment to the headlamps is
necessary, see your dealer.
Bulb Replacement
For the proper type of replacement
bulbs, or any bulb changing procedure
not listed in this section, contact your
dealer.
Caution
Do not replace incandescent bulbs
with aftermarket LED replacement
bulbs. This can cause damage to
the vehicle electrical system.