warning light CADILLAC CT4 2021 Workshop Manual

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
DRIVING AND OPERATING 283
Warning (Continued)
To help avoid death or injury,
always check for pedestrians
around the vehicle before backing
up. Be ready to take action and
apply the brakes. SeeDefensive
Driving 0204. Keep the RVC,
taillamps, and back-up lamps clean
and in good repair.
Rear Pedestrian Alert can be set to Off
or Alert. See “Rear Pedestrian
Detection ”in “Collision/Detection
Systems” underVehicle Personalization
0 117. If equipped, alerts can be set to
beeps or seat pulses. See “Alert Type”
in “Collision/Detection Systems” under
Vehicle Personalization 0117.
Assistance Systems for
Driving
If equipped, when driving the vehicle
in a forward gear, Forward Collision
Alert (FCA), Lane Departure Warning
(LDW), Lane Keep Assist (LKA), Side
Blind Zone Alert (SBZA), Lane Change
Alert (LCA), Automatic Emergency
Braking (AEB), and/or the Front Pedestrian Braking (FPB) System can
help to avoid a crash or reduce crash
damage.
Forward Collision Alert
(FCA) System
The FCA system may help to avoid or
reduce the harm caused by front-end
crashes. When approaching a vehicle
ahead too quickly, FCA provides a red
flashing alert on the windshield and
rapidly beeps or pulses the driver seat.
FCA also lights an amber visual alert
if following another vehicle too
closely.
FCA detects vehicles within a distance
of approximately 60 m (197 ft) and
operates at speeds above 8 km/h
(5 mph). If the vehicle has Adaptive
Cruise Control (ACC), it can detect
vehicles to distances of approximately
110 m (360 ft) and operates at all
speeds. See
Adaptive Cruise Control
(Advanced) 0251.
{Warning
FCA is a warning system and does
not apply the brakes. When
approaching a slower-moving or
stopped vehicle ahead too rapidly,
or when following a vehicle too
closely, FCA may not provide a
warning with enough time to help
avoid a crash. It also may not
provide any warning at all. FCA
does not warn of pedestrians,
animals, signs, guardrails, bridges,
construction barrels, or other
objects. Be ready to take action and
apply the brakes. See Defensive
Driving 0204.
FCA can be disabled through vehicle
personalization. See "Collision/
Detection Systems" under Vehicle
Personalization 0117.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
DRIVING AND OPERATING 289
{Warning
FPB may alert or automatically
brake the vehicle suddenly in
situations where it is unexpected
and undesired. It could falsely alert
or brake for objects similar in shape
or size to pedestrians, including
shadows. This is normal operation
and the vehicle does not need
service. To override Automatic
Braking, firmly press the accelerator
pedal, if it is safe to do so.
Automatic Braking can be disabled
through vehicle personalization. See
“Front Pedestrian Detection ”in
“Collision/Detection Systems” under
Vehicle Personalization 0117.
{Warning
Using the Front Pedestrian Braking
system while towing a trailer could
cause you to lose control of the
vehicle and crash. Turn the system
to Alert or Off when towing a
trailer.
Cleaning the System
If FPB does not seem to operate
properly, cleaning the outside of the
windshield in front of the rearview
mirror may correct the issue.
Side Blind Zone
Alert (SBZA)
If equipped, the SBZA system is a
lane-changing aid that assists drivers
with avoiding crashes that occur with
moving vehicles in the side blind
zone, or blind spot areas. When the
vehicle is in a forward gear, the left or
right side mirror display will light up
if a moving vehicle is detected in that
blind zone. If the turn signal is
activated and a vehicle is also
detected on the same side, the display
will flash as an extra warning not to
change lanes. Since this system is part
of the Lane Change Alert (LCA)
system, read the entire LCA section
before using this feature.
Lane Change Alert (LCA)
If equipped, the LCA system is a
lane-changing aid that assists drivers
with avoiding lane change crashes
that occur with moving vehicles in the
side blind zone (or spot) areas or with
vehicles rapidly approaching these
areas from behind. The LCA warning
display will light up in the
corresponding outside mirror and will
flash if the turn signal is on.
{Warning
LCA does not alert the driver to
vehicles outside of the system
detection zones, pedestrians,
bicyclists, or animals. It may not
provide alerts when changing lanes
under all driving conditions. Failure
to use proper care when changing
lanes may result in injury, death,
or vehicle damage. Before making a
lane change, always check mirrors,
glance over your shoulder, and use
the turn signals.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
290 DRIVING AND OPERATING
LCA Detection Zones
1. SBZA Detection Zone
2. LCA Detection Zone
The LCA sensor covers a zone of
approximately one lane over from
both sides of the vehicle, or 3.5 m
(11 ft). The height of the zone is
approximately between 0.5 m (1.5 ft)
and 2 m (6 ft) off the ground. The Side
Blind Zone Alert (SBZA) warning area
starts at approximately the middle of
the vehicle and goes back 5 m (16 ft).
Drivers are also warned of vehicles
rapidly approaching from up to 70 m
(230 ft) behind the vehicle.
How the System Works
The LCA symbol lights up in the
outside mirrors when the system
detects a moving vehicle in the next
lane over that is in the side blind zone
or rapidly approaching that zone from
behind. A lit LCA symbol indicates it
may be unsafe to change lanes. Before
making a lane change, check the LCA
display, check mirrors, glance over
your shoulder, and use the turn
signals.
Left Outside MirrorDisplayRight Outside
Mirror Display
When the vehicle is started, both
outside mirror LCA displays will
briefly come on to indicate the system
is operating. When the vehicle is in a
forward gear, the left or right outside
mirror display will light up if a moving
vehicle is detected in the next lane
over in that blind zone or rapidly
approaching that zone. If the turn signal is activated in the same
direction as a detected vehicle, this
display will flash as an extra warning
not to change lanes.
LCA can be disabled. When you
disable LCA, Side Blind Zone Alert is
also disabled. See
“Collision/Detection
Systems” underVehicle Personalization
0 117. If LCA is disabled by the driver,
the LCA mirror displays will not
light up.
When the System Does Not
Seem to Work Properly
The LCA system requires some driving
for the system to calibrate to
maximum performance. This
calibration may occur more quickly if
the vehicle is driving on a straight
highway road with traffic and roadside
objects (e.g., guardrails, barriers).
LCA displays may not come on when
passing a vehicle quickly, for a
stopped vehicle, or when towing a
trailer. The LCA detection zones that
extend back from the side of the
vehicle do not move further back
when a trailer is towed. Use caution
while changing lanes when towing a

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
DRIVING AND OPERATING 291
trailer. LCA may alert to objects
attached to the vehicle, such as a
trailer, bicycle, or object extending out
to either side of the vehicle. Attached
objects may also interfere with the
detection of vehicles. This is normal
system operation; the vehicle does not
need service.
LCA may not always alert the driver to
vehicles in the next lane over,
especially in wet conditions or when
driving on sharp curves. The system
does not need to be serviced. The
system may light up due to guardrails,
signs, trees, shrubs, and other
non-moving objects. This is normal
system operation; the vehicle does not
need service.
LCA may not operate when the LCA
sensors in the left or right corners of
the rear bumper are covered with
mud, dirt, snow, ice, or slush, or in
heavy rainstorms. For cleaning
instructions, see "Washing the
Vehicle" underExterior Care0370.
If the DIC still displays the system
unavailable message after cleaning both sides of the vehicle toward the
rear corners of the vehicle, see your
dealer.
If the LCA displays do not light up
when moving vehicles are in the side
blind zone or are rapidly approaching
this zone and the system is clean, the
system may need service. Take the
vehicle to your dealer.
Radio Frequency Information
See
Radio Frequency Statement 0409.
Lane Keep Assist (LKA)
If equipped, LKA may help avoid
crashes due to unintentional lane
departures. This system uses a camera
to detect lane markings between
60 km/h (37 mph) and 180 km/h
(112 mph). It may assist by gently
turning the steering wheel if the
vehicle approaches a detected lane
marking. It may also provide a Lane
Departure Warning (LDW) alert if the
vehicle crosses a detected lane
marking. LKA can be overridden by
turning the steering wheel. This
system is not intended to keep the
vehicle centered in the lane. LKA will not assist and alert if the turn signal
is active in the direction of lane
departure, or if it detects that you are
accelerating, braking or actively
steering.
{Warning
The LKA system does not
continuously steer the vehicle.
It may not keep the vehicle in the
lane or give a Lane Departure
Warning (LDW) alert, even if a lane
marking is detected.
The LKA and LDW systems
may not:
.Provide an alert or enough
steering assist to avoid a lane
departure or crash.
.Detect lane markings under poor
weather or visibility conditions.
This can occur if the windshield
or headlamps are blocked by dirt,
snow, or ice; if they are not in
proper condition; or if the sun
shines directly into the camera.
.Detect road edges.
(Continued)

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
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292 DRIVING AND OPERATING
Warning (Continued)
.Detect lanes on winding or hilly
roads.
If LKA only detects lane markings
on one side of the road, it will only
assist or provide an LDW alert
when approaching the lane on the
side where it has detected a lane
marking. Even with LKA and LDW,
you must steer the vehicle. Always
keep your attention on the road and
maintain proper vehicle position
within the lane, or vehicle damage,
injury, or death could occur. Always
keep the windshield, headlamps,
and camera sensors clean and in
good repair. Do not use LKA in bad
weather conditions or on roads with
unclear lane markings, such as
construction zones.
{Warning
Using LKA while towing a trailer or
on slippery roads could cause loss
of control of the vehicle and a
crash. Turn the system off.
How the System Works
LKA uses a camera sensor installed on
the windshield ahead of the rearview
mirror to detect lane markings. It may
provide brief steering assist if it
detects an unintended lane departure.
It may further provide an audible alert
or the driver seat may pulse indicating
that a lane marking has been crossed.
To turn LKA on and off, press
Aon
the center stack. If equipped, the
indicator light on the button comes
on when LKA is on and turns off
when LKA is disabled.
When on,
Ais white, if equipped,
indicating that the system is not ready
to assist.
Ais green if LKA is ready
to assist. LKA may assist by gently
turning the steering wheel if the
vehicle approaches a detected lane
marking.
Ais amber when
assisting. It may also provide a Lane
Departure Warning (LDW) alert by
flashing
Aamber if the vehicle
crosses a detected lane marking.
Additionally, there may be three
beeps, or the driver seat may pulse three times, on the right or left,
depending on the lane departure
direction.
Take Steering
The LKA system does not
continuously steer the vehicle. If LKA
does not detect active driver steering,
an alert and chime may be provided.
Steer the vehicle to dismiss. LKA may
become temporarily unavailable after
repeated take steering alerts.
When the System Does Not
Seem to Work Properly
The system performance may be
affected by:
.Close vehicles ahead.
.Sudden lighting changes, such as
when driving through tunnels.
.Banked roads.
.Roads with poor lane markings,
such as two-lane roads.
If the LKA system is not functioning
properly when lane markings are
clearly visible, cleaning the windshield
may help.

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
304 VEHICLE CARE
Vehicle Care
General Information
General Information . . . . . . . . . . . . . 305
California Proposition65 Warning . . . . . . . . . . . . . . . . . . . . . 305
California Perchlorate Materials Requirements . . . . . . . . . . . . . . . . . . . 306
Accessories and Modifications . . . . . . . . . . . . . . . . . . . 306
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . . . . . . 306
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . . . . . . 309
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . 312
Engine Oil Life System . . . . . . . . . . . 314
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315
Engine Air Filter Life System . . . . 315
Engine Air Cleaner/Filter . . . . . . . . . 316
Cooling System . . . . . . . . . . . . . . . . . . . 317
Engine Overheating . . . . . . . . . . . . . . 322
Washer Fluid . . . . . . . . . . . . . . . . . . . . . 323
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323 Brake Pad Life System (If
Equipped) . . . . . . . . . . . . . . . . . . . . . . . 324
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . 325
Battery - North America . . . . . . . . . 326
All-Wheel Drive . . . . . . . . . . . . . . . . . . 327
Park Brake and P (Park) Mechanism Check . . . . . . . . . . . . . . 327
Wiper Blade Replacement . . . . . . . 327
Windshield Replacement . . . . . . . . 328
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . 328
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . 329
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . 329
Halogen Bulbs . . . . . . . . . . . . . . . . . . . . 330
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . . . . . . . . . . . . . 330
LED Lighting . . . . . . . . . . . . . . . . . . . . . 330
Front Turn Signal Lamps . . . . . . . . 330
Electrical System
Electrical System Overload . . . . . . 330
Fuses and Circuit Breakers . . . . . . 331
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
Instrument Panel Fuse Block . . . . 334
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339
All-Season Tires . . . . . . . . . . . . . . . . . . 339
Winter Tires . . . . . . . . . . . . . . . . . . . . . . 340
Run-Flat Tires . . . . . . . . . . . . . . . . . . . . 340
Self-Sealing Tires . . . . . . . . . . . . . . . . . 341
Low-Profile Tires . . . . . . . . . . . . . . . . . 341
Summer Tires . . . . . . . . . . . . . . . . . . . . 341
Tire Sidewall Labeling . . . . . . . . . . . 342
Tire Designations . . . . . . . . . . . . . . . . . 343
Tire Terminology andDefinitions . . . . . . . . . . . . . . . . . . . . . . 344
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . 346
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . . . . . . 347
Tire Pressure Monitor System . . . 348
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . . . . . . 349
Tire Inspection . . . . . . . . . . . . . . . . . . . 352
Tire Rotation . . . . . . . . . . . . . . . . . . . . . 352
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353
Buying New Tires . . . . . . . . . . . . . . . . 354
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . . . . . 356
Uniform Tire Quality Grading . . . 356
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . . . . . . 357

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) -
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330 VEHICLE CARE
Halogen Bulbs
{Warning
Halogen bulbs have pressurized gas
inside and can burst if you drop or
scratch the bulb. You or others
could be injured. Be sure to read
and follow the instructions on the
bulb package.
High Intensity Discharge
(HID) Lighting
{Warning
The High Intensity Discharge (HID)
lighting system operates at a very
high voltage. If you try to service
any of the system components, you
could be seriously injured. Have
your dealer or a qualified technician
service them.
After an HID headlamp bulb has been
replaced, the beam might be a slightly
different shade than it was originally.
This is normal.
LED Lighting
This vehicle has several LED lamps.
For replacement of any LED lighting
assembly, contact your dealer.
Front Turn Signal Lamps
Uplevel
See your dealer for turn signal
replacement.
Base level
To replace one of these lamps: 1. Open the hood.
2. If your vehicle is equipped with a beauty cover, remove the beauty
cover to get access to the bulb.3. Turn the bulb socketcounterclockwise to remove it from
the headlamp assembly.
4. Unplug the electrical connector from the bulb by releasing the clip
on the connector.
5. Replace the bulb and reverse Steps 1–4 to reinstall.
Electrical System
Electrical System Overload
The vehicle has fuses and circuit
breakers to protect against an
electrical system overload.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
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VEHICLE CARE 349
soon as possible, and inflate them to
the proper pressure. Driving on a
significantly under-inflated tire causes
the tire to overheat and can lead to
tire failure. Under-inflation also
reduces fuel efficiency and tire tread
life, and may affect the vehicle's
handling and stopping ability.
Please note that the TPMS is not a
substitute for proper tire maintenance,
and it is the driver's responsibility to
maintain correct tire pressure, even if
under-inflation has not reached the
level to trigger illumination of the
TPMS low tire pressure telltale.
Your vehicle has also been equipped
with a TPMS malfunction indicator to
indicate when the system is not
operating properly. The TPMS
malfunction indicator is combined
with the low tire pressure telltale.
When the system detects a
malfunction, the telltale will flash for
approximately one minute and then
remain continuously illuminated. This
sequence will continue upon
subsequent vehicle start-ups as long
as the malfunction exists.When the malfunction indicator is
illuminated, the system may not be
able to detect or signal low tire
pressure as intended. TPMS
malfunctions may occur for a variety
of reasons, including the installation
of replacement or alternate tires or
wheels on the vehicle that prevent the
TPMS from functioning properly.
Always check the TPMS malfunction
telltale after replacing one or more
tires or wheels on your vehicle to
ensure that the replacement or
alternate tires and wheels allow the
TPMS to continue to function
properly.
See
Tire Pressure Monitor Operation
0 349.
See Radio Frequency Statement 0409.
Tire Pressure Monitor
Operation
This vehicle may have a Tire Pressure
Monitor System (TPMS). The TPMS is
designed to warn the driver when a
low tire pressure condition exists. TPMS sensors are mounted onto each
tire and wheel assembly, excluding the
spare tire and wheel assembly. The
TPMS sensors monitor the air
pressure in the tires and transmit the
tire pressure readings to a receiver
located in the vehicle.
When a low tire pressure condition is
detected, the TPMS illuminates the
low tire pressure warning light located
on the instrument cluster. If the
warning light comes on, stop as soon
as possible and inflate the tires to the
recommended pressure shown on the
Tire and Loading Information label.
See
Vehicle Load Limits 0214.
A message to check the pressure in a
specific tire displays in the Driver
Information Center (DIC). The low tire
pressure warning light and the DIC
warning message come on at each
ignition cycle until the tires are
inflated to the correct inflation