2023 CADILLAC CT4 brake light

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
368 Vehicle Care
Vehicle Care
General Information
General Information . . . . . . 369
California PerchlorateMaterials
Requirements . . . . . . . . . . . . . 370
Accessories and Modifications . . . . . . . . . . . . . 370
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . 370
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . 371
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . 373
Engine Oil . . . . . . . . . . . . . . . . . . . . 378
Engine Oil Life System . . . 381
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 382
Manual Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 382
Hydraulic Clutch . . . . . . . . . . . 383
Engine Air Filter Life System . . . . . . . . . . . . . . . . . . . . . . 383
Engine Air Cleaner/ Filter . . . . . . . . . . . . . . . . . . . . . . . . . 384
Cooling System . . . . . . . . . . . . 386
Engine Overheating . . . . . . . 391 Washer Fluid . . . . . . . . . . . . . . . . 393
Brakes . . . . . . . . . . . . . . . . . . . . . . . . 393
Brake Pad Life System (If
Equipped) . . . . . . . . . . . . . . . . . . 396
Brake Fluid . . . . . . . . . . . . . . . . . . 398
Battery - North
America . . . . . . . . . . . . . . . . . . . . . 399
All-Wheel Drive . . . . . . . . . . . . 400
Park Brake and P (Park) Mechanism Check . . . . . . . 400
Wiper Blade Replacement . . . . . . . . . . . . . . 401
Windshield Replacement . . . . . . . . . . . . . . 401
Gas Strut(s) . . . . . . . . . . . . . . . . . 402
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . . . . . . . . . . . . . . . 403
Bulb Replacement
Bulb Replacement . . . . . . . . 403
Halogen Bulbs . . . . . . . . . . . . . . 403
High Intensity Discharge(HID) Lighting . . . . . . . . . . . . . 403
LED Lighting . . . . . . . . . . . . . . . . 403
Front Turn Signal Lamps . . . . . . . . . . . . . . . . . . . . . . . 404
Electrical System
Electrical SystemOverload . . . . . . . . . . . . . . . . . . . 404
Fuses and Circuit Breakers . . . . . . . . . . . . . . . . . . . 406
Engine Compartment
Fuse Block . . . . . . . . . . . . . . . . . 407
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 409
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . 411
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . 413
All-Season Tires . . . . . . . . . . . . 414
Winter Tires . . . . . . . . . . . . . . . . . 414
Run-Flat Tires . . . . . . . . . . . . . . . 415
Self-Sealing Tires . . . . . . . . . . 415
Low-Profile Tires . . . . . . . . . . 416
Summer Tires . . . . . . . . . . . . . . . 416
Tire Sidewall Labeling . . . . 417
Tire Designations . . . . . . . . . . 418
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . . . 419
Tire Pressure . . . . . . . . . . . . . . . 422
Tire Pressure for High-Speed
Operation . . . . . . . . . . . . . . . . . . 423
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . . . . 424

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
398 Vehicle Care
Brake Fluid
The brake/clutch master
cylinder reservoir is filled with
GM approved DOT 4 brake
fluid as indicated on the
reservoir cap. See Engine
Compartment Overview0373
for the location of the
reservoir.
Checking Brake Fluid
Place the vehicle in P (Park) or
Neutral with the parking brake
applied if equipped with a
manual transmission. 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/
clutch hydraulic system.
Have the brake/clutch
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/
clutch 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/
clutch 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/clutch hydraulic
system.
When the brake/clutch fluid
falls to a low level, the brake
warning light comes on. See
Brake System Warning Light
0 120.
Brake fluid absorbs water over
time which degrades the
effectiveness of the brake
fluid. Replace brake fluid at the
specified intervals to prevent
increased stopping distance.
See Maintenance Schedule
0 469.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
408 Vehicle Care
Fuses Usage
1 Long Range RadarFront Sensor
2 Park/Daytime Running Lamps
3 Exterior Lighting Module 4
4 Exterior Lighting Module 7
5 Headlamp Level
6 –
Fuses Usage
7 Electronic Brake
Control Module
8 Washer Pump
9 –
10 –
11 –
12 Horn
13 Front Wiper
Fuses Usage
14 Exterior Lighting Module 6
15 Exterior Lighting Module 1
16 Exterior Lighting Module 5
17 Exterior Lighting Module 3
18 Aero Shutter
19 –
20 –
21 Virtual Key System/ Power Sounder
Module
22 Engine Control Module Battery
23 Transmission Control Module
24 Active Engine Mount
25 –
26 Engine Control Module
27 Injectors/Ignition 2
28 Charged Air Cooler/ Not Used
29 Transmission Aux Oil Pump/Transmission
Reverse Lock Out

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
428 Vehicle Care
When the low tire pressure
warning light comes on:1. Park the vehicle in a safe, level place.
2. Set the parking brake firmly.
3. Place the vehicle in P (Park).
4. Add air to the tire that is underinflated. The turn
signal lamp will flash.
When the recommended
pressure is reached, the
horn sounds once and the
turn signal lamp will stop
flashing and briefly turn
solid.
Repeat these steps for all
underinflated tires that have
illuminated the low tire
pressure warning light.
{Warning
Overinflating a tire could
cause the tire to rupture
and you or others could be
injured. Do not exceed the (Continued)
Warning (Continued)
maximum pressure listed on
the tire sidewall. See Tire
Sidewall Labeling 0417 and
Vehicle Load Limits 0255.
If the tire is overinflated by
more than 35 kPa (5 psi), the
horn will sound multiple times
and the turn signal lamp will
continue to flash for several
seconds after filling stops. To
release and correct the
pressure, while the turn signal
lamp is still flashing, briefly
press the center of the valve
stem. When the recommended
pressure is reached, the horn
sounds once.
If the turn signal lamp does
not flash within 15 seconds
after starting to inflate the
tire, the tire fill alert has not
been activated or is not
working. If the hazard warning flashers
are on, the tire fill alert visual
feedback will not work
properly.
The TPMS will not activate the
tire fill alert properly under the
following conditions:
.There is interference from
an external device or
transmitter.
.The air pressure from the
inflation device is not
sufficient to inflate the tire.
.There is a malfunction in
the TPMS.
.There is a malfunction in the
horn or turn signal lamps.
.The identification code of
the TPMS sensor is not
registered to the system.
.The battery of the TPMS
sensor is low.
If the tire fill alert does not
operate due to TPMS
interference, move the vehicle
about 1 m (3 ft) back or
forward and try again. If the

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
432 Vehicle Care
Vehicle Storage
Tires age when stored
normally mounted on a parked
vehicle. Park a vehicle that will
be stored for at least a month
in a cool, dry, clean area away
from direct sunlight to slow
aging. This area should be free
of grease, gasoline, or other
substances that can
deteriorate rubber.
Parking for an extended
period can cause flat spots on
the tires that may result in
vibrations while driving. When
storing a vehicle for at least a
month, remove the tires or
raise the vehicle to reduce the
weight from the tires.
Buying New Tires
GM has developed and
matched specific tires for
the vehicle. The original
equipment tires installed
were designed to meet
General Motors Tire
Performance CriteriaSpecification (TPC Spec)
system rating. When
replacement tires are
needed, GM strongly
recommends buying tires
with the same TPC Spec
rating.
GM's exclusive TPC Spec
system considers over a
dozen critical specifications
that impact the overall
performance of the vehicle,
including brake system
performance, ride and
handling, traction control,
and tire pressure
monitoring performance.
GM's TPC Spec number is
molded onto the tire's
sidewall near the tire size.
If the tires have an
all-season tread design, the
TPC Spec number will be
followed by MS for mud
and snow. See Tire
Sidewall Labeling
0417 for
additional information. GM recommends replacing
worn tires in complete sets
of four. Uniform tread
depth on all tires will help
to maintain the
performance of the vehicle.
Braking and handling
performance may be
adversely affected if all the
tires are not replaced at
the same time. If proper
rotation and maintenance
have been done, all four
tires should wear out at
about the same time.
However, if it is necessary
to replace only one axle set
of worn tires, place the
new tires on the rear axle.
See Tire Rotation
0429.{Warning
Tires could explode
during improper service.
Attempting to mount or
dismount a tire could
(Continued)

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
436 Vehicle Care
balancing are not necessary
on a regular basis. Consider an
alignment check if there is
unusual tire wear or the
vehicle is significantly pulling
to one side or the other. Some
slight pull to the left or right,
depending on the crown of the
road and/or other road
surface variations such as
troughs or ruts, is normal.
If the vehicle is vibrating when
driving on a smooth road, the
tires and wheels may need to
be rebalanced. See your
dealer for proper diagnosis.
Wheel Replacement
Replace any wheel that is
bent, cracked, or badly rusted
or corroded. If wheel nuts
keep coming loose, the wheel,
wheel bolts, and wheel nuts
should be replaced. If the
wheel leaks air, replace it.
Some aluminum wheels can be
repaired. See your dealer if
any of these conditions exist.
Your dealer will know the kind
of wheel that is needed.Each new wheel should have
the same load-carrying
capacity, diameter, width,
offset, and be mounted the
same way as the one it
replaces.
Replace wheels, wheel bolts,
wheel nuts, or Tire Pressure
Monitor System (TPMS)
sensors with new GM original
equipment parts.
{Warning
Using the wrong
replacement wheels, wheel
bolts, or wheel nuts can be
dangerous. It could affect
the braking and handling of
the vehicle. Tires can lose air
and cause loss of control,
resulting in a crash. Always
use the correct wheel, wheel
bolts, and wheel nuts for
replacement.
{Warning
Replacing a wheel with a
used one is dangerous. How
it has been used or how far
it has been driven may be
unknown. It could fail
suddenly and cause a crash.
When replacing wheels, use
a new GM original
equipment wheel.
Caution
The wrong wheel can also
cause problems with bearing
life, brake cooling,
speedometer or odometer
calibration, headlamp aim,
bumper height, vehicle
ground clearance, and tire or
tire chain clearance to the
body and chassis.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Service and Maintenance 473
Exterior Lights
.Visual inspection
Windshield and Wipers
.Visual inspection
Battery
.Battery visual inspection
.Battery test results
.Battery cables and
connections
Systems, Fluids, and
Visible Leak Inspection
.Engine oil
.Transmission
.Drive axle
.Transfer case
.Engine cooling system
.Power steering, if equipped
.Fuel system
.Windshield washer fluid
Tire Inspection
.Tire pressure, tread depth,
and wear
.Rotation, if applicable
.Alignment check, optional
.Reset tire pressure monitor
.Check tire sealant expiration
date, if equipped
.Check spare tire, if equipped
Brakes
.Check brake system
Visible and Functional
Inspections
.Seat belt components
.Exhaust system
.Accelerator pedal
.Passenger compartment air
filter, if equipped
.Engine air filter
.Hoses
.Belts
.Shocks and struts
.Steering components
.Axle boots or driveshaft and
u-joints
.Compartment lift struts,
if equipped
.Floor mats secured, no
interference with pedals
.Horn
.Ignition lock, if equipped
.Starter switch
.Evaporative control system
Lubricate
.Chassis components
Special Application
Services
.Severe Commercial Use
Vehicles Only: Lubricate
chassis components every
oil change.
.Have underbody flushing
service performed. See
"Underbody Maintenance" in
Exterior Care 0455.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/10/22
510 INDEX
AlertLane Change . . . . . . . . . . . . . . . 349
Rear Cross Traffic . . . . . . . . . 341
Side Blind
Zone (SBZA) . . . . . . . . . . . . . . . 349
All-Season Tires . . . . . . . . . . . . . . 414
All-Wheel Drive . . . . . . . . 286, 400
AM-FM Radio . . . . . . . . . . . . . . . . . . 162
Antenna Multi-band . . . . . . . . . . . . . . . . . . . . 166
Antilock Brake
System (ABS) . . . . . . . . . . . . . . . 286
Warning Light . . . . . . . . . . . . . . . . 121
Appearance Care Exterior . . . . . . . . . . . . . . . . . . . . . . . 455
Interior . . . . . . . . . . . . . . . . . . . . . . . . . 461
Apple CarPlay and Android Auto . . . . . . . . . . . . . . . . 204
Assistance Program, Roadside . . . . . . . . . . . . . . . . . . . . . 487
Assistance Systems
Driving . . . . . . . . . . . . . . . . . . . . . . . . 342
Parking and Backing . . . . . . 335
Audio Bluetooth . . . . . . . . . . . . . . . . . . . . . 169
Automatic Dimming Mirrors . . . . . . . . . . . . . 30
Door Locks . . . . . . . . . . . . . . . . . . . . . 21 Automatic (cont'd)
Emergency
Braking (AEB) . . . . . . . . . . . . . 345
Emergency Braking (AEB) Disabled Light . . . . . 123
Headlamp System . . . . . . . . . . 148
Transmission . . . . . . . . . 272, 275
Transmission Fluid . . . . . . . . 382
Vehicle Hold Light . . . . . . . . . . 122
Automatic Transmission Manual Mode . . . . . . . . . 280, 281
Automatic Vehicle
Hold (AVH) . . . . . . . . . . . . . . . . . . . 289
Avoiding Untrusted Media Devices . . . . . . . . . . . . . . . 166
B
BatteryExterior LightingBattery Saver . . . . . . . . . . . . . . 153
Load Management . . . . . . . . . 152
Power Protection . . . . . . . . . . 153
Battery - North America . . . . . . . . . . . . . . . . .399, 447
Blade Replacement, Wiper . . . . . . . . . . . . . . . . . . . . . . . . . . . 401
Bluetooth Audio . . . . . . . . . . . . . . . . . . . . . . . . . . . 169 Bluetooth (cont'd)
Overview . . . . . . . . . . . . . . . . 198, 199
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . 398
Pad Life System . . . . . . . . . . . 396
System Warning Light . . . . 120
Brake Pad Life System . . . . 396
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . 393
Antilock . . . . . . . . . . . . . . . . . . . . . . . 286
Brake Assist . . . . . . . . . . . . . . . . 289
Electric Brake Boost . . . . . 286
Electric Parking Brake . . . . 287
Braking . . . . . . . . . . . . . . . . . . . . . . . . . 235 AutomaticEmergency (AEB) . . . . . . . . 345
Reverse Automatic . . . . . . . 340
Braking System FrontPedestrian (FPB) . . . . . . . . . 346
Break-In, New Vehicle . . . . . . 259
Buckle To Drive . . . . . . . . . . . . . . . . 50
Bulb Replacement . . . . . . . . . . . 403 Front Turn SignalLamps . . . . . . . . . . . . . . . . . . . . . . . 404
Halogen Bulbs . . . . . . . . . . . . . . 403
Headlamp Aiming . . . . . . . . . . 403