brake CADILLAC XT4 2021 Repair Manual

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DRIVING AND OPERATING 263
Cruise control may be disengaged
when the Front Pedestrian Alert
occurs.
Automatic Braking
If FPB detects it is about to crash into
a pedestrian directly ahead, and the
brakes have not been applied, FPB
may automatically brake moderately
or brake hard. This can help to avoid
some very low speed pedestrian
crashes or reduce pedestrian injury.
FPB can automatically brake to
detected pedestrians between 8 km/h
(5 mph) and 80 km/h (50 mph).
Automatic braking levels may be
reduced under certain conditions,
such as higher speeds.
If this happens, Automatic Braking
may engage the Electric Parking Brake
(EPB) to hold the vehicle at a stop.
Release the EPB. A firm press of the
accelerator pedal will also release
Automatic Braking and the EPB.
{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 0120.
{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

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DRIVING AND OPERATING 271
and may not be covered by the vehicle
warranty. SeeRecommended Fuel
0 267.
Driving Characteristics and
Towing Tips
{Warning
You can lose control when towing a
trailer if the correct equipment is
not used or the vehicle is not driven
properly. For example, if the trailer
is too heavy or the trailer brakes are
inadequate for the load, the vehicle
may not stop as expected. You and
others could be seriously injured.
The vehicle may also be damaged,
and the repairs would not be
covered by the vehicle warranty.
Pull a trailer only if all the steps in
this section have been followed. Ask
your dealer for advice and
information about towing a trailer
with the vehicle.
Driving with a Trailer
Trailering is different than just driving
the vehicle by itself. Trailering means
changes in handling, acceleration,
braking, durability, and fuel economy.
Successful, safe trailering takes correct
equipment, and it has to be used
properly.
The following information has many
time-tested, important trailering tips
and safety rules. Many of these are
important for your safety and that of
your passengers. Read this section
carefully before pulling a trailer.
When towing a trailer:
.Become familiar with and follow all
state and local laws that apply to
trailer towing. These requirements
vary from state to state.
.State laws may require the use of
extended side view mirrors. Even if
not required, you should install
extended side view mirrors if your
visibility is limited or restricted
while towing.
.Do not tow a trailer during the first
800 km (500 mi) of vehicle use to
prevent damage to the engine, axle,
or other parts.
.It is recommended to perform the
first oil change before heavy towing.
.During the first 800 km (500 mi) of
trailer towing, do not drive over
80 km/h (50 mph) and do not make
starts at full throttle.
.Vehicles can tow in D (Drive). If the
transmission downshifts too often, a
lower gear may be selected using
Manual Mode See Manual Mode
0 231.
If equipped, the following driver
assistance features should be turned
off when towing a trailer:
.Adaptive Cruise Control (ACC)
.Super Cruise Control
.Lane Keep Assist (LKA)
.Park Assist
.Automatic Parking Assist (APA)
.Reverse Automatic Braking (RAB)
If equipped, the following driver
assistance features should be turned
to alert or off when towing a trailer:

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272 DRIVING AND OPERATING
.Automatic Emergency
Braking (AEB)
.Intelligent Brake Assist (IBA)
.Front Pedestrian Braking (FPB)
If equipped with Lane Change Alert
(LCA), 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
trailer.
If equipped with Rear Cross Traffic
Alert (RCTA), use caution while
backing up when towing a trailer, as
the RCTA detection zones that extend
out from the back of the vehicle do
not move further back when a trailer
is towed.
{Warning
To prevent serious injury or death
from carbon monoxide (CO), when
towing a trailer:
.Do not drive with the liftgate,
trunk/hatch, or rear-most
window open. (Continued)
Warning (Continued)
.Fully open the air outlets on or
under the instrument panel.
.Adjust the climate control
system to a setting that brings in
only outside air. See“Climate
Control Systems” in the Index.
For more information about carbon
monoxide, see Engine Exhaust
0 226.
Towing a trailer requires experience.
The combination of the vehicle and
trailer is longer and not as responsive
as the vehicle itself. Get used to the
handling and braking of the
combination by driving on a level road
surface before driving on public roads.
The trailer structure, the tires, and the
brakes must be all be rated to carry
the intended cargo. Inadequate trailer
equipment can cause the combination
to operate in an unexpected or unsafe
manner. Before driving, inspect all
trailer hitch parts and attachments,
safety chains, electrical connectors,
lamps, tires, and mirrors. See Towing
Equipment 0277. If the trailer has electric brakes, start the combination
moving and then manually apply the
trailer brake controller to check that
the trailer brakes work. During the
trip, occasionally check that the cargo
and trailer are secure and that the
lamps and any trailer brakes are
working.
Towing with a Stability Control
System
When towing, the stability control
system might be heard. The system
reacts to vehicle movement caused by
the trailer, which mainly occurs
during cornering. This is normal when
towing heavier trailers.
Following Distance
Stay at least twice as far behind the
vehicle ahead as you would when
driving without a trailer. This can help
to avoid heavy braking and sudden
turns.
Passing
More passing distance is needed when
towing a trailer. The combination of
the vehicle and trailer will not
accelerate as quickly and is much

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DRIVING AND OPERATING 273
longer than the vehicle alone. It is
necessary to go much farther beyond
the passed vehicle before returning to
the lane. Pass on level roadways.
Avoid passing on hills if possible.
Backing Up
Hold the bottom of the steering wheel
with one hand. To move the trailer to
the left, move that hand to the left. To
move the trailer to the right, move
that hand to the right. Always back up
slowly and, if possible, have someone
guide you.
Making TurnsCaution
Turn more slowly and make wider
arcs when towing a trailer to
prevent damage to your vehicle.
Making very sharp turns could
cause the trailer to contact the
vehicle.
Make wider turns than normal when
towing, so the trailer will not go over
soft shoulders, over curbs, or strike road signs, trees, or other objects.
Always signal turns well in advance.
Do not steer or brake suddenly.
Driving on Grades
Reduce speed and shift to a lower gear
before starting down a long or steep
downhill grade. If the transmission is
not shifted down, the brakes may
overheat and result in reduced braking
efficiency.
The vehicle can tow in D (Drive). Shift
the transmission to a lower gear if the
transmission shifts too often under
heavy loads and/or hilly conditions.
When towing at higher altitudes,
engine coolant will boil at a lower
temperature than at lower altitudes.
If the engine is turned off immediately
after towing at high altitude on steep
uphill grades, the vehicle could show
signs similar to engine overheating. To
avoid this, let the engine run,
preferably on level ground, with the
transmission in P (Park) for a few
minutes before turning the engine off.
If the overheat warning comes on, see
Engine Overheating
0294.
Parking on Hills
{Warning
To prevent serious injury or death,
always park your vehicle and trailer
on a level surface when possible.
When parking your vehicle and your
trailer on a hill: 1. Press the brake pedal, but do not shift into P (Park) yet. Turn the
wheels into the curb if facing
downhill or into traffic if facing
uphill.
2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, gradually release the brake
pedal to allow the chocks to absorb
the load of the trailer.
4. Reapply the brake pedal. Then apply the parking brake and shift
into P (Park).
5. Release the brake pedal.

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274 DRIVING AND OPERATING
Leaving After Parking on a Hill
1. Apply and hold the brake pedal.
.Start the engine.
.Shift into a gear.
.Release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
Maintenance When Trailer
Towing
The vehicle needs service more often
when used to tow trailers. See
Maintenance Schedule 0358. It is
especially important to check the
automatic transmission fluid, engine
oil, axle lubricant, belts, cooling
system, and brake system before and
during each trip.
Check periodically that all nuts and
bolts on the trailer hitch are tight.
Engine Cooling When Trailer
Towing
The cooling system may temporarily
overheat during severe operating
conditions. See Engine Overheating
0 294.
Trailer Towing
Caution
Towing a trailer improperly can
damage the vehicle and result in
costly repairs not covered by the
vehicle warranty. To tow a trailer
correctly, follow the directions in
this section and see your dealer for
important information about
towing a trailer with the vehicle.
Trailering is different than just driving
the vehicle by itself. Trailering means
changes in handling, acceleration,
braking, durability, and fuel economy.
Successful, safe trailering takes correct
equipment, and it has to be used
properly.
The following information has many
time-tested, important trailering tips
and safety rules. Many of these are important for your safety and that of
your passengers. Read this section
carefully before pulling a trailer.
Trailer Weight
{Warning
Never exceed the towing capacity
for your vehicle.
Safe trailering requires monitoring the
weight, speed, altitude, road grades,
outside temperature, dimensions of
the front of the trailer, and how
frequently the vehicle is used to tow a
trailer.
When towing a trailer, the combined
weight of the vehicle, vehicle contents,
trailer, and trailer contents must be
below all of the maximum weight
ratings for the vehicle, including:
.GCWR: Gross Combined Weight
Rating
.GVWR: Gross Vehicle Weight Rating
.Maximum Trailer Weight Rating
.Maximum Trailer Tongue Weight
Rating

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DRIVING AND OPERATING 275
See“Trailer Brakes ”under Towing
Equipment 0277.
The only way to be sure the weight is
not exceeding any of these ratings is
to weigh the tow vehicle and trailer
combination, fully loaded for the trip,
getting individual weights for each of
these items.
{Warning
You and others could be seriously
injured or killed if the trailer is too
heavy or the trailer brakes are
inadequate for the load. The vehicle
may be damaged, and the repairs
would not be covered by the vehicle
warranty.
Only tow a trailer if all the steps in
this section have been followed. Ask
your dealer for advice and
information about towing a trailer.
Gross Combined Weight
Rating (GCWR)
GCWR is the total allowable weight of
the completely loaded vehicle and
trailer including any fuel, passengers,
cargo, equipment, and accessories. Do
not exceed the GCWR for your vehicle.
The GCWR for the vehicle is on the
Tow Rating Chart following.
Gross Vehicle Weight
Rating (GVWR)
For information about the vehicle's
maximum load capacity, see Vehicle
Load Limits 0215. When calculating
the GVWR with a trailer attached, the
trailer tongue weight must be
included as part of the weight the
vehicle is carrying.
Maximum Trailer Weight
The maximum trailer weight rating is
calculated assuming the tow vehicle
has a driver, a front seat passenger,
and all required trailering equipment.
This value represents the heaviest
trailer the vehicle can tow, but it may
be necessary to reduce the trailer
weight to stay within the GCW,
GVWR, maximum trailer tongue load,
or GAWR-RR for the vehicle.
Use the tow rating chart to determine
how much the trailer can weigh, based
on the vehicle model and options.

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278 DRIVING AND OPERATING
Hitch Cover
To remove hitch cover, if equipped:1. Remove the two fasteners on the lower tabs.
2. Pull the lower edge of the cover to about a 45 degree angle.
3. Pull the cover downward to disengage the upper attachments.
To reinstall the hitch cover: 1. Hold cover at a 45 degree angle to the vehicle and push the upper
tabs into the slots in the bumper.
2. Push the bottom of the cover forward until the lower tabs line up
with the lower slots. 3. Snap the hitch cover into place by
pushing the upper corners forward.
4. Reinstall the two fasteners on the lower tabs.
Consider using mechanical sway
controls with any trailer. Ask a
trailering professional about sway
controls or refer to the trailer
manufacturer's recommendations and
instructions.
Tires
.Do not tow a trailer while using a
compact spare tire on the vehicle.
.Tires must be properly inflated to
support loads while towing a trailer.
See Tires 0308 for instructions on
proper tire inflation.
Safety Chains
Always attach chains between the
vehicle and the trailer, and attach the
chains to the holes on the trailer hitch
platform. Instructions about safety
chains may be provided by the hitch
manufacturer or by the trailer
manufacturer. Cross the safety chains under the
tongue of the trailer to help prevent
the tongue from contacting the road if
it becomes separated from the hitch.
Always leave just enough slack so the
combination can turn. Never allow
safety chains to drag on the ground.
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.

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DRIVING AND OPERATING 279
Trailer Wiring Harness
Basic Trailer Wiring
The trailer wiring harness is located at
the rear of the vehicle and is tied to
the vehicle's frame. The harness
connector can be plugged into a
trailer connector available through
your dealer.
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.
Trailer Sway Control (TSC)
Vehicles with StabiliTrak/Electronic
Stability Control (ESC) have a Trailer
Sway Control (TSC) feature. Trailersway is unintended side-to-side
motion of a trailer while towing. If the
vehicle is towing a trailer and the TSC
detects that sway is increasing, the
vehicle brakes are selectively applied
at each wheel, to help reduce
excessive trailer sway. If equipped with
the Integrated Trailer Brake Control
(ITBC) system, and the trailer has an
electric brake system, StabiliTrak/ESC
may also apply the trailer brakes.
If TSC is enabled, the Traction Control
System (TCS)/StabiliTrak/ESC warning
light will flash on the instrument
cluster. Reduce vehicle speed by
gradually removing your foot from the
accelerator. If trailer sway continues,
StabiliTrak/ESC can reduce engine
torque to help slow the vehicle. TSC
will not function if StabiliTrak/ESC is
turned off. See
Traction Control/
Electronic Stability Control 0235.
{Warning
Trailer sway can result in a crash
and in serious injury or death, even
if the vehicle is equipped with TSC.
If the trailer begins to sway, reduce
vehicle speed by gradually removing
your foot from the accelerator. Then
pull over to check the trailer and
vehicle to help correct possible
causes, including an improperly or
overloaded trailer, unrestrained
cargo, improper trailer hitch
configuration, or improperly
inflated or incorrect vehicle or
trailer tires. See Towing Equipment
0 277 for trailer ratings and hitch
setup recommendations.
Trailer Tires
Special Trailer (ST) tires differ from
vehicle tires. Trailer tires are designed
with stiff sidewalls to help prevent
sway and to support heavy loads.
These features can make it difficult to
determine if the trailer tire pressures
are low only based on a visual
inspection.

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VEHICLE CARE 281
Vehicle Care
General Information
General Information . . . . . . . . . . . . . 282
California Proposition65 Warning . . . . . . . . . . . . . . . . . . . . . 282
California Perchlorate Materials Requirements . . . . . . . . . . . . . . . . . . . 282
Accessories and Modifications . . . . . . . . . . . . . . . . . . . 283
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . . . . . . 283
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . . . . . . 285
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . 286
Engine Oil Life System . . . . . . . . . . . 288
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289
Engine Air Filter Life System . . . . 289
Engine Air Cleaner/Filter . . . . . . . . . 290
Cooling System . . . . . . . . . . . . . . . . . . . 291
Engine Overheating . . . . . . . . . . . . . . 294
Washer Fluid . . . . . . . . . . . . . . . . . . . . . 295
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . 296
Battery - North America . . . . . . . . . 297
All-Wheel Drive . . . . . . . . . . . . . . . . . . 298 Park Brake and P (Park)
Mechanism Check . . . . . . . . . . . . . . 298
Wiper Blade Replacement . . . . . . . 299
Windshield Replacement . . . . . . . . 300
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . 300
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . 301
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . 301
LED Lighting . . . . . . . . . . . . . . . . . . . . . 301
Back-Up Lamps . . . . . . . . . . . . . . . . . . . 302
Electrical System
Electrical System Overload . . . . . . 302
Fuses and Circuit Breakers . . . . . . 303
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303
Instrument Panel Fuse Block . . . . 306
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308
All-Season Tires . . . . . . . . . . . . . . . . . . 309
Winter Tires . . . . . . . . . . . . . . . . . . . . . . 310
Summer Tires . . . . . . . . . . . . . . . . . . . . 310
Tire Sidewall Labeling . . . . . . . . . . . 310
Tire Designations . . . . . . . . . . . . . . . . . 312
Tire Terminology and Definitions . . . . . . . . . . . . . . . . . . . . . . 313
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . 316 Tire Pressure for High-Speed
Operation . . . . . . . . . . . . . . . . . . . . . . . . 317
Tire Pressure Monitor System . . . 318
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . . . . . . 319
Tire Inspection . . . . . . . . . . . . . . . . . . . 322
Tire Rotation . . . . . . . . . . . . . . . . . . . . . 323
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324
Buying New Tires . . . . . . . . . . . . . . . . 325
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . . . . . 326
Uniform Tire Quality Grading . . . 326
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . . . . . . 328
Wheel Replacement . . . . . . . . . . . . . . 328
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . 328
If a Tire Goes Flat . . . . . . . . . . . . . . . . 329
Tire Sealant and Compressor Kit . . . . . . . . . . . . . . . . . 331
Storing the Tire Sealant and Compressor Kit . . . . . . . . . . . . . . . . . 336
Tire Changing . . . . . . . . . . . . . . . . . . . . . 337
Compact Spare Tire . . . . . . . . . . . . . . 341
Jump Starting
Jump Starting - North America . . . . . . . . . . . . . . . . . . . . . . . . . 342

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VEHICLE CARE 283
may contain perchlorate materials.
Perchlorate Material–special
handling may apply. See
www.dtsc.ca.gov/hazardouswaste/
perchlorate.
Accessories and
Modifications
Adding non-dealer accessories or
making modifications to the vehicle
can affect vehicle performance and
safety, including such things as
airbags, braking, stability, ride and
handling, emissions systems,
aerodynamics, durability, and
electronic systems like antilock
brakes, traction control, and stability
control. These accessories or
modifications could even cause
malfunction or damage not covered by
the vehicle warranty.
Damage to suspension components
caused by modifying vehicle height
outside of factory settings will not be
covered by the vehicle warranty.
Damage to vehicle components
resulting from modifications or the
installation or use of non-GM certified
parts, including control module or software modifications, is not covered
under the terms of the vehicle
warranty and may affect remaining
warranty coverage for affected parts.
GM Accessories are designed to
complement and function with other
systems on the vehicle. See your
dealer to accessorize the vehicle using
genuine GM Accessories installed by a
dealer technician.
Also, see
Adding Equipment to the
Airbag-Equipped Vehicle 064.
Vehicle Checks
Doing Your Own
Service Work
{Warning
It can be dangerous to work on
your vehicle if you do not have the
proper knowledge, service manual,
tools, or parts. Always follow
owner’s manual procedures and
consult the service manual for your
vehicle before doing any
service work. If doing some of your own service
work, use the proper service manual.
It tells you much more about how to
service the vehicle than this manual
can. To order the proper service
manual, see
Publication Ordering
Information 0383.
This vehicle has an airbag system.
Before attempting to do your own
service work, see Servicing the
Airbag-Equipped Vehicle 064.
If equipped with remote vehicle start,
open the hood before performing any
service work to prevent remote
starting the vehicle accidentally. See
Remote Vehicle Start 014.
Keep a record with all parts receipts
and list the mileage and the date of
any service work performed. See
Maintenance Records 0369.
Caution
Even small amounts of
contamination can cause damage to
vehicle systems. Do not allow
contaminants to contact the fluids,
reservoir caps, or dipsticks.