2021 CADILLAC CT4 steering

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
336 VEHICLE CARE
FusesUsage
13 –
14 –
15 –
16 –
17 –
18 Display/Infotainment/ USB/Multi-function
control module
19 Airbag/ Automatic occupant sensing /
Data link connection/
Wireless charging
module/ Virtual key
module
20 Power steering column module/
Electronic steering
column lock 2
21 Driver monitor system/Performance
data recorder
22 –
23 –
24 – Fuses
Usage
25 USB
26 –
27 –
28 –
29 –
30 –
31 Headlamp level
32 –
33 Body ignition/IP ignition
34 Exhaust valve
35 Transmission control module ignition/
Engine control
module ignition/Shift
ignition/Brake
ignition
36 Shift module
37 Body control module 1/Electronic
park brake switch
38 Center stack module Fuses
Usage
39 Steering wheel controls
40 Body control module 2
41 Body control module 3
42 Body control module 4
Circuit
Breakers Usage
CB1 Auxiliary power outlet 1
CB2 Auxiliary power outlet 2
Relays Usage
1 Run after park/ Accessory
2 Run crank
3 –
4 –
5 –

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
VEHICLE CARE 359
Caution
If the vehicle is equipped with a
tire size other than 235/40R18 or
235/35R19, use tire chains only
where legal and only when
necessary. Use low profile chains
that add no more than 12 mm
thickness to the tire tread and inner
sidewall. Use chains that are the
proper size for the tires. Install
them on the tires of the rear axle.
Don't use chains on the tires of the
front axle. Tighten them as tightly
as possible with the ends securely
fastened. Drive slowly and follow
the chain manufacturer's
instructions. If the chains contact
the vehicle, stop and retighten
them. If the contact continues, slow
down until it stops. Driving too fast
or spinning the wheels with chains
on will damage the vehicle.
If a Tire Goes Flat
It is unusual for a tire to blow out
while driving, especially if the tires are
maintained properly. If air goes out of
a tire, it is much more likely to leak
out slowly. SeeTires0339 for
additional information. But if there
ever is a blowout, here are a few tips
about what to expect and what to do:
If a front tire fails, the flat tire creates
a drag that pulls the vehicle toward
that side. Take your foot off the
accelerator pedal and grip the steering
wheel firmly. Steer to maintain lane
position, and then gently brake to a
stop, well off the road, if possible.
A rear blowout, particularly on a
curve, acts much like a skid and may
require the same correction as used in
a skid. Stop pressing the accelerator
pedal and steer to straighten the
vehicle. It may be very bumpy and
noisy. Gently brake to a stop, well off
the road, if possible.{Warning
Driving on a flat tire will cause
permanent damage to the tire.
Re-inflating a tire after it has been
driven on while severely
underinflated or flat may cause a
blowout and a serious crash. Never
attempt to re-inflate a tire that has
been driven on while severely
underinflated or flat. Have your
dealer or an authorized tire service
center repair or replace the flat tire
as soon as possible.
If the vehicle has run-flat tires, there
is no need to stop on the side of the
road to change a flat tire. See Run-Flat
Tires 0340.
{Warning
Special tools and procedures are
required to service a run-flat tire.
If these special tools and
procedures are not used, injury or
vehicle damage may occur. Always
(Continued)

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
374 VEHICLE CARE
Caution
To avoid surface damage on wheels
and wheel trim, do not use strong
soaps, chemicals, abrasive polishes,
cleaners, or brushes. Use only GM
approved cleaners. Do not drive the
vehicle through an automatic car
wash that uses silicon carbide tire/
wheel cleaning brushes. Damage
could occur and the repairs would
not be covered by the vehicle
warranty.
Brake System
Visually inspect brake lines and hoses
for proper hook-up, binding, leaks,
cracks, chafing, etc. Inspect disc brake
pads for wear and rotors for surface
condition. Inspect drum brake linings/
shoes for wear or cracks. Inspect all
other brake parts.
Steering, Suspension, and
Chassis Components
Visually inspect steering, suspension,
and chassis components for damaged,
loose, or missing parts or signs of
wear at least once a year.Inspect power steering for proper
attachment, connections, binding,
leaks, cracks, chafing, etc.
Visually check constant velocity joint
boots and axle seals for leaks.
Body Component Lubrication
Lubricate all key lock cylinders, hood
hinges, liftgate hinges, and the steel
fuel door hinge, unless the
components are plastic. Applying
silicone grease on weatherstrips with a
clean cloth will make them last
longer, seal better, and not stick or
squeak.
Underbody Maintenance
At least twice a year, spring and fall,
use plain water to flush any corrosive
materials from the underbody. Take
care to thoroughly clean any areas
where mud and other debris can
collect.
Do not directly power wash the
transfer case and/or front/rear axle
output seals. High pressure water can
overcome the seals and contaminate
the fluid. Contaminated fluid will
decrease the life of the transfer case
and/or axles and should be replaced
Sheet Metal Damage
If the vehicle is damaged and requires
sheet metal repair or replacement,
make sure the body repair shop
applies anti-corrosion material to
parts repaired or replaced to restore
corrosion protection.
Original manufacturer replacement
parts will provide the corrosion
protection while maintaining the
vehicle warranty.
Finish Damage
Quickly repair minor chips and
scratches with touch-up materials
available from your dealer to avoid
corrosion. Larger areas of finish
damage can be corrected in your
dealer's body and paint shop.
Chemical Paint Spotting
Airborne pollutants can fall upon and
attack painted vehicle surfaces
causing blotchy, ring-shaped
discolorations, and small, irregular

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
SERVICE AND MAINTENANCE 381
oil life system must be reset. Your
trained dealer technician can perform
this work. If the engine oil life system
is reset accidentally, service the
vehicle within 5 000 km (3,000 mi)
since the last service. Reset the oil life
system when the oil is changed. See
Engine Oil Life System0314.
Air Conditioning Desiccant
(Replace Every Seven Years)
The air conditioning system requires
maintenance every seven years. This
service requires replacement of the
desiccant to help the longevity and
efficient operation of the air
conditioning system. This service can
be complex. See your dealer.
Tire Rotation and Required
Services Every 12 000 km
(7,500 mi)
Rotate the tires, if recommended for
the vehicle, and perform the following
services. See Tire Rotation0352.
.Check engine oil level and oil
life percentage. If needed, change
engine oil and filter, and reset oil
life system. See Engine Oil0312 and
Engine Oil Life System 0314.
.If equipped, check the air filter
life percentage. If necessary, replace
the engine air filter and reset the
engine air filter life system. See
Engine Air Filter Life System 0315.
If the vehicle is not equipped with
the engine air filter life system,
inspect the engine air cleaner filter.
See Engine Air Cleaner/Filter 0316.
.Check engine coolant level. See
Cooling System 0317.
.Check windshield washer fluid level.
See Washer Fluid 0323.
.Check tire inflation pressures. See
Tire Pressure 0346.
.Inspect tire wear. See Tire Inspection
0 352.
.Visually check for fluid leaks.
.Inspect brake system. See Exterior
Care 0370.
.Visually inspect steering,
suspension, and chassis
components for damage, including
cracks or tears in the rubber boots,
loose or missing parts, or signs of
wear at least once a year. See
Exterior Care 0370.
.Inspect power steering for proper
attachment, connections, binding,
leaks, cracks, chafing, etc.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
390 SERVICE AND MAINTENANCE
Shocks and Struts
Shocks and struts help aid in control
for a smoother ride.
.Signs of wear may include steering
wheel vibration, bounce/sway while
braking, longer stopping distance,
or uneven tire wear.
.As part of the multi-point
inspection, trained dealer
technicians can visually inspect the
shocks and struts for signs of
leaking, blown seals, or damage, and
can advise when service is needed.
Tires
Tires need to be properly inflated,
rotated, and balanced. Maintaining
the tires can save money and fuel, and
can reduce the risk of tire failure.
.Signs that the tires need to be
replaced include three or more
visible treadwear indicators; cord or
fabric showing through the rubber;
cracks or cuts in the tread or
sidewall; or a bulge or split in
the tire.
.Trained dealer technicians can
inspect and recommend the right
tires. Your dealer can also provide
tire/wheel balancing services to
ensure smooth vehicle operation at
all speeds. Your dealer sells and
services name brand tires.
Vehicle Care
To help keep the vehicle looking like
new, vehicle care products are
available from your dealer. For
information on how to clean and
protect the vehicle’s interior and
exterior, see Interior Care 0375 and
Exterior Care 0370.
Wheel Alignment
Wheel alignment is critical for
ensuring that the tires deliver optimal
wear and performance.
.Signs that the alignment may need
to be adjusted include pulling,
improper vehicle handling,
or unusual tire wear.
.Your dealer has the required
equipment to ensure proper wheel
alignment. Windshield
For safety, appearance, and the best
viewing, keep the windshield clean
and clear.
.Signs of damage include scratches,
cracks, and chips.
.Trained dealer technicians can
inspect the windshield and
recommend proper replacement if
needed.
Wiper Blades
Wiper blades need to be cleaned and
kept in good condition to provide a
clear view.
.Signs of wear include streaking,
skipping across the windshield, and
worn or split rubber.
.Trained dealer technicians can
check the wiper blades and replace
them when needed.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
408 CUSTOMER INFORMATION
Managing the Vehicle Damage
Repair Process
In the event that the vehicle requires
damage repairs, GM recommends that
you take an active role in its repair.
If you have a pre-determined repair
facility of choice, take the vehicle
there, or have it towed there. Specify
to the facility that any required
replacement collision parts be original
equipment parts, either new Genuine
GM parts or recycled original GM
parts. Remember, recycled parts will
not be covered by the GM vehicle
warranty.
Insurance pays the bill for the repair,
but you must live with the repair.
Depending on your policy limits, your
insurance company may initially value
the repair using aftermarket parts.
Discuss this with the repair
professional, and insist on Genuine
GM parts. Remember, if the vehicle is
leased, you may be obligated to have
the vehicle repaired with Genuine GM
parts, even if your insurance coverage
does not pay the full cost.If another party's insurance company
is paying for the repairs, you are not
obligated to accept a repair valuation
based on that insurance company's
collision policy repair limits, as you
have no contractual limits with that
company. In such cases, you can have
control of the repair and parts choices
as long as the cost stays within
reasonable limits.
Publication Ordering
Information
Service Manuals
Service manuals have the diagnosis
and repair information on the engine,
transmission, axle, suspension, brakes,
electrical system, steering system,
body, etc.
Customer Literature
Owner’s manuals are written
specifically for owners and are
intended to provide basic operational
information about the vehicle. The
owner’s manual includes the
Maintenance Schedule for all models.Customer literature publications
available for purchase include owner’s
manuals, warranty manuals, and
portfolios. Portfolios include an
owner’s manual, warranty manual,
if applicable, and zip lock bag or
pouch.
Current and Past Models
Service manuals and customer
literature are available for many
current and past model year GM
vehicles.
To order, call 1-800-551-4123
Monday–Friday, 8:00 a.m.–6:00 p.m.
eastern time
For credit card orders only (VISA,
MasterCard, or Discover), see Helm,
Inc. at: www.helminc.com.
To order by mail, write to:
Helm, Incorporated
Attention: Customer Service
47911 Halyard Drive
Plymouth, MI 48170
Make checks payable in U.S. funds.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
INDEX 423
Chains, Tire . . . . . . . . . . . . . . . . . . . . . . . . . 358
ChargingWireless . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Charging System Light . . . . . . . . . . . . . . 97
Check Engine Light (MalfunctionIndicator) . . . . . . . . . . . . . . . . . . . . . . . . . 97
Child Restraints Infants and Young Children . . . . . . . 60
Lower Anchors and Tethersfor Children . . . . . . . . . . . . . . . . . . . . . . . 65
Older Children . . . . . . . . . . . . . . . . . . . . . 59
Securing . . . . . . . . . . . . . . . . . . . . . . . . 72, 74
Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Circuit Breakers . . . . . . . . . . . . . . . . . . . . . 331
Cleaning Exterior Care . . . . . . . . . . . . . . . . . . . . . . 370
Interior Care . . . . . . . . . . . . . . . . . . . . . . 375
Climate Control Systems Dual Automatic . . . . . . . . . . . . . . . . . . . 196
Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Cluster, Instrument . . . . . . . . . . . . . . 88, 90
Collision Damage Repair . . . . . . . . . . . 406
Compartments Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Compass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Competitive Driving Mode . . . . . . . . . 246
Composite Materials . . . . . . . . . . . . . . . . 218 Compressor Kit, Tire Sealant . . . . . . . 360
Connected Services
Connections . . . . . . . . . . . . . . . . . . . . . . . 419
Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . 420
Navigation . . . . . . . . . . . . . . . . . . . . . . . . . 418
Connections Connected Services . . . . . . . . . . . . . . . 419
Control Traction and ElectronicStability . . . . . . . . . . . . . . . . . . . . . . . . . . 239
Control of a Vehicle . . . . . . . . . . . . . . . . 204
Controls
Steering Wheel . . . . . . . . . . . . . . . . . . . . 137
Convex Mirrors . . . . . . . . . . . . . . . . . . . . . . 23
Coolant Engine Temperature Gauge . . . 94, 95
Engine Temperature Warning
Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
Cooling System . . . . . . . . . . . . . . . . . . . . . 317
Cornering Lamps . . . . . . . . . . . . . . . . . . . 130
Courtesy Lamps . . . . . . . . . . . . . . . . . . . . . 130
Courtesy Transportation Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405
Coverage Explanations . . . . . . . . . . . . . 163
Cruise Control . . . . . . . . . . . . . . . . . . . . . . . 248
Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Cruise Control, Adaptive . . . . . . . . . . . 251 Cruise Control, Super . . . . . . . . . . . . . . . 260
Cupholders . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Customer Assistance . . . . . . . . . . . . . . . 402
Offices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 401
Text Telephone (TTY) Users . . . . . 402
Customer Information Publications Ordering
Information . . . . . . . . . . . . . . . . . . . . . . 408
Customer Satisfaction Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . 399
Cybersecurity . . . . . . . . . . . . . . . . . . . . . . . . 410
D
Damage Repair, Collision . . . . . . . . . . . 406
Danger, Warning, and Caution . . . . . . . . 2
Data Collection Infotainment System . . . . . . . . . . . . . 412
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 412
Data Recorders, Event . . . . . . . . . . . . . . 411
Database Coverage Explanations . . . . . . . . . . . . . . . . . . . . . . 163
Daytime Running Lamps (DRL) . . . 128
Defensive Driving . . . . . . . . . . . . . . . . . . . 204
Delayed Locking . . . . . . . . . . . . . . . . . . . . . 17
Destination . . . . . . . . . . . . . . . . . . . . . . . . . . 155
Diagnostics Connected Services . . . . . . . . . . . . . . . 420
Differential, Limited-Slip . . . . . . . . . . . 248

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
426 INDEX
Headlamps (cont'd)High/Low Beam Changer . . . . . . . . . 128
Lamps On Reminder . . . . . . . . . . . . . . 106
Heated Steering Wheel . . . . . . . . . . . . . . . . . . . . . 82
Heated and Ventilated Front Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Heated Mirrors . . . . . . . . . . . . . . . . . . . . . . . 25
Heater Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222
Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
High-Beam On Light . . . . . . . . . . . . . . . . 105
High-Speed Operation . . . . . . . . . . . . . . 347
Hill and Mountain Roads . . . . . . . . . . 212
Hill Start Assist (HSA) . . . . . . . . . . . . . 238
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
How to Wear Seat Belts Properly . . . 42
HVAC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
I
If the System Needs Service . . . . . . . 163
Ignition Positions . . . . . . . . . . . . . . . . . . . 219
Immobilizer . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Indicator Pedestrian Ahead . . . . . . . . . . . . . . . . . 102
Vehicle Ahead . . . . . . . . . . . . . . . . . . . . . 102 Infants and Young Children,
Restraints . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Information Publication Ordering . . . . . . . . . . . . . 408
Infotainment System . . . . . . . . . . . . . . . 412
Instrument Cluster . . . . . . . . . . . . . . 88, 90
Instrument Panel Overview . . . . . . . . . . . 4
Interior Rearview Mirrors . . . . . . . . . . . 26
Introduction . . . . . . . . . . . . . . . . . . . . . . 1, 134
J
Jump Starting - North America . . . . 366
K
Keyless Entry Remote (RKE) System . . . . . . . . . . . . . . . 7
Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
L
Labeling, Tire Sidewall . . . . . . . . . . . . . 342
Lamps
Cornering . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Courtesy . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Daytime Running (DRL) . . . . . . . . . . 128
Dome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Exterior Controls . . . . . . . . . . . . . . . . . . 126
Exterior Lamps Off Reminder . . . . 128
Exterior Lighting BatterySaver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 Lamps (cont'd)
Front Turn Signal . . . . . . . . . . . . . . . . . 330
Malfunction Indicator (Check
Engine) . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
On Reminder . . . . . . . . . . . . . . . . . . . . . . 106
Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Lane Change Alert (LCA) . . . . . . . . . . . 289
Lane Keep Assist (LKA) . . . . . . . . . . . . 291
Lane Keep Assist Light . . . . . . . . . . . . . 101
Lap-Shoulder Belt . . . . . . . . . . . . . . . . . . . . 44
LATCH System Replacing Parts after a Crash . . . . . 72
LATCH, Lower Anchors and Tethers for Children . . . . . . . . . . . . . . . 65
LED Lighting . . . . . . . . . . . . . . . . . . . . . . . . 330
Light Performance Shifting . . . . . . . . . . . . . 101
Lighting Entry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Exit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
Illumination Control . . . . . . . . . . . . . . 130
LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
Lights Airbag Readiness . . . . . . . . . . . . . . . . . . 96
Antilock Brake System (ABS)Warning . . . . . . . . . . . . . . . . . . . . . . . . . 100
Automatic Vehicle Hold . . . . . . . . . . 101
Brake System Warning . . . . . . . . . . . . 99