Speed CADILLAC XT6 2021 Owners Manual

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
318 VEHICLE CARE
Check to see if coolant is visible in the
coolant surge tank. If the coolant
inside the coolant surge tank is
boiling, do not do anything else until
it cools down. If coolant is visible but
the coolant level mark is not at or
above the indicated mark, add a 50/
50 mixture of clean, drinkable water
and DEX-COOL coolant. Be sure the
cooling system is cool before this is
done. SeeEngine Overheating 0320.
The coolant surge tank is in the
engine compartment on the driver
side of the vehicle. See Engine
Compartment Overview 0308.
How to Add Coolant to the
Surge Tank
{Warning
Spilling coolant on hot engine parts
can burn you. Coolant contains
ethylene glycol and it will burn if
the engine parts are hot enough.
{Warning
Steam and scalding liquids from a
hot cooling system are under
pressure. Turning the pressure cap,
even a little, can cause them to
come out at high speed and you
could be burned. Never turn the cap
when the cooling system, including
the pressure cap, is hot. Wait for
the cooling system and pressure
cap to cool.
Caution
Failure to follow the specific
coolant fill procedure could cause
the engine to overheat and could
(Continued)
Caution (Continued)
cause system damage. If coolant is
not visible in the surge tank,
contact your dealer.
The coolant surge tank pressure cap
can be removed when the cooling
system, including the surge tank
pressure cap and upper radiator hose,
is no longer hot.
Coolant Fill Instructions (3.6L
Engine Only)
1. Turn the pressure cap slowly counterclockwise. If a hiss is heard,
wait for that to stop. A hiss means
there is still some pressure left.
2. Keep turning the pressure cap slowly and remove it.

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
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4. Put the vehicle in Service Mode.See Ignition Positions 0232.
5. Turn off the air conditioning.
6. Set the parking brake.
7. At the same time, press the accelerator and the brake for
automatic transmission vehicles for
two seconds, then release.
At the end of the cycle, check the
coolant level in the surge tank and
add coolant, if it is low. Turn off the
vehicle, allow the Engine Control
Module (ECM) to go to sleep, about
two minutes, and repeat steps 3-7.
Listen for pump activation and
movement of the control valves while
watching the level of the tank. If the
tank empties, turn the ignition off,
carefully remove the surge tank cap,
refill to the indicated mark and repeat
steps 3-6. The fill and air removal
process will run for approximately
10 minutes.
Engine Overheating
The vehicle has several indicators to
warn of the engine overheating. There is an engine coolant
temperature gauge on the instrument
cluster. See
Engine Coolant Temperature
Gauge 0113. The vehicle may also
display a message on the Driver
Information Center (DIC).
If the decision is made not to lift the
hood when this warning appears, get
service help right away. See Roadside
Service 0401.
If the decision is made to lift the
hood, make sure the vehicle is parked
on a level surface. Then check to see if
the engine cooling fan is running.
If the engine is overheating, the fan
should be running. If it is not, do not
continue to run the engine. Have the
vehicle serviced.
Caution
Do not run the engine if there is a
leak in the engine cooling system.
This can cause a loss of all coolant
and can damage the system and
vehicle. Have any leaks fixed
right away.
If Steam Is Coming from the
Engine Compartment
{Warning
Steam and scalding liquids from a
hot cooling system are under
pressure. Turning the pressure cap,
even a little, can cause them to
come out at high speed and you
could be burned. Never turn the cap
when the cooling system, including
the pressure cap, is hot. Wait for
the cooling system and pressure
cap to cool.
If No Steam Is Coming from the
Engine Compartment
If an engine overheat warning is
displayed but no steam can be seen or
heard, the problem may not be too
serious. Sometimes the engine can get
a little too hot when the vehicle:
.Climbs a long hill on a hot day.
.Stops after high-speed driving.
.Idles for long periods in traffic.

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If the overheat warning is displayed
with no sign of steam:1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature and to the highest fan
speed. Open the windows as
necessary.
3. When it is safe to do so, pull off the road, shift to P (Park) or
N (Neutral), and let the engine idle.
If the engine coolant temperature
gauge is no longer in the overheated
area or the engine coolant
temperature warning light no longer
displays, the vehicle can be driven.
Continue to drive the vehicle slowly
for about 10 minutes. Keep a safe
distance from the vehicle in front.
If the warning does not come back on,
continue to drive normally and have
the cooling system checked for proper
fill and function.
If the warning continues, pull over,
stop, and park the vehicle right away.
If there is no sign of steam, idle the
engine for three minutes while parked.
If the warning is still displayed, turn
off the engine until it cools down.Washer Fluid
What to Use
When windshield washer fluid is
needed, be sure to read the
manufacturer's instructions before
use. If operating the vehicle in an area
where the temperature may fall below
freezing, use a fluid that has sufficient
protection against freezing.
Adding Washer Fluid
The appropriate message will appear
in the Driver Information Center (DIC)
when the fluid level is low.
Open the cap with the washer symbol
on it. Add washer fluid until the tank
is full. See Engine Compartment
Overview 0308 for reservoir location.
Caution
.Do not use washer fluid that
contains any type of water
repellent coating. This can cause
the wiper blades to chatter
or skip.
.Do not use engine coolant
(antifreeze) in the windshield
washer. It can damage the
windshield washer system and
paint.
.Do not mix water with
ready-to-use washer fluid. Water
can cause the solution to freeze
and damage the washer fluid
tank and other parts of the
washer system.
.When using concentrated washer
fluid, follow the manufacturer
instructions for adding water.
.Fill the washer fluid tank only
three-quarters full when it is very
cold. This allows for fluid
expansion if freezing occurs,
which could damage the tank if
it is completely full.

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Wheels and Tires
Tires
Every new GM vehicle has
high-quality tires made by a
leading tire manufacturer. See the
warranty manual for information
regarding the tire warranty and
where to get service. For
additional information refer to the
tire manufacturer.
{Warning
.Poorly maintained and
improperly used tires are
dangerous.
.Overloading the tires can
cause overheating as a result
of too much flexing. There
could be a blowout and a
serious crash. SeeVehicle
Load Limits 0228.
.Underinflated tires pose the
same danger as overloaded
tires. The resulting crash
(Continued)
Warning (Continued)
could cause serious injury.
Check all tires frequently to
maintain the recommended
pressure. Tire pressure should
be checked when the tires
are cold.
.Overinflated tires are more
likely to be cut, punctured,
or broken by a sudden impact
— such as when hitting a
pothole. Keep tires at the
recommended pressure.
.Worn or old tires can cause a
crash. If the tread is badly
worn, replace them.
.Replace any tires that have
been damaged by impacts
with potholes, curbs, etc.
.Improperly repaired tires can
cause a crash. Only your
dealer or an authorized tire
(Continued)
Warning (Continued)
service center should repair,
replace, dismount, and mount
the tires.
.Do not spin the tires in
excess of 56 km/h (35 mph)
on slippery surfaces such as
snow, mud, ice, etc. Excessive
spinning may cause the tires
to explode.
See Tire Pressure for High-Speed
Operation 0345 for inflation
pressure adjustment for
high-speed driving.
All-Season Tires
This vehicle may come with all-season
tires. These tires are designed to
provide good overall performance on
most road surfaces and weather
conditions. Original equipment tires
designed to GM's specific tire
performance criteria have a TPC
specification code molded onto the
sidewall. Original equipment

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
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338 VEHICLE CARE
all-season tires can be identified by
the last two characters of this TPC
code, which will be“MS.”
Consider installing winter tires on the
vehicle if frequent driving on snow or
ice-covered roads is expected.
All-season tires provide adequate
performance for most winter driving
conditions, but they may not offer the
same level of traction or performance
as winter tires on snow or ice-covered
roads. See Winter Tires 0338.
Winter Tires
This vehicle was not originally
equipped with winter tires. Winter
tires are designed for increased
traction on snow and ice-covered
roads. Consider installing winter tires
on the vehicle if frequent driving on
ice or snow covered roads is expected.
See your dealer for details regarding
winter tire availability and proper tire
selection. Also, see Buying New Tires
0 353.
With winter tires, there may be
decreased dry road traction, increased
road noise, and shorter tread life. After changing to winter tires, be alert
for changes in vehicle handling and
braking.
If using winter tires:
.Use tires of the same brand and
tread type on all four wheel
positions.
.Use only radial ply tires of the same
size, load range, and speed rating as
the original equipment tires.
Winter tires with the same speed
rating as the original equipment tires
may not be available for H, V, W, Y,
and ZR speed rated tires. If winter
tires with a lower speed rating are
chosen, never exceed the tire's
maximum speed capability.
Summer Tires
This vehicle may come with 235/
65R18 or 235/55R20 high performance
summer tires. These tires have a
special tread and compound that are
optimized for maximum dry and wet
road performance. This special tread
and compound will have decreased
performance in cold climates, and on
ice and snow. It is recommended that
winter tires be installed on the vehicle if frequent driving at temperatures
below approximately 5 °C (40 °F) or on
ice or snow covered roads is expected.
See
Winter Tires 0338.
Caution
High performance summer tires
have rubber compounds that lose
flexibility and may develop surface
cracks in the tread area at
temperatures below −7 °C (20 °F).
Always store high performance
summer tires indoors and at
temperatures above −7 °C (20 °F)
when not in use. If the tires have
been subjected to −7 °C (20 °F) or
less, let them warm up in a heated
space to at least 5 °C (40 °F) for
24 hours or more before being
installed or driving a vehicle on
which they are installed. Do not
apply heat or blow heated air
directly on the tires. Always inspect
tires before use. See Tire Inspection
0 350.

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
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(7) Maximum Cold Inf lation
Load Limit
:Maximum load that
can be carried and the maximum
pressure needed to support
that load.
Compact Spare Tire Example
(1) Tire Ply Material:The type
of cord and number of plies in the
sidewall and under the tread.
(2) Temporary Use Only
:The
compact spare tire or temporary
use tire should not be driven at
speeds over 80 km/h (50 mph).
The compact spare tire is for
emergency use when a regular road tire has lost air and gone flat.
If the vehicle has a compact spare
tire, see
Compact Spare Tire 0364
and
If a Tire Goes Flat 0357.
(3) Tire Identification Number
(TIN)
:The letters and numbers
following the DOT (Department of
Transportation) code are the Tire
Identification Number (TIN). The
TIN shows the manufacturer and
plant code, tire size, and date the
tire was manufactured. The TIN is
molded onto both sides of the tire,
although only one side may have
the date of manufacture.
(4) Maximum Cold Inf lation
Load Limit
:Maximum load that
can be carried and the maximum
pressure needed to support
that load.
(5) Tire Inf lation
:The temporary
use tire or compact spare tire
should be inflated to 420 kPa (60 psi). For more information on
tire pressure and inflation see
Tire
Pressure 0343.
(6) Tire Size
:A combination of
letters and numbers define a tire's
width, height, aspect ratio,
construction type, and service
description. The letter “T”as the
first character in the tire size
means the tire is for temporary
use only.
(7) TPC Spec (Tire Performance
Criteria Specification)
:Original
equipment tires designed to GM's
specific tire performance criteria
have a TPC specification code
molded onto the sidewall. GM's
TPC specifications meet or exceed
all federal safety guidelines.
Tire Designations
Tire Size
The example shows a typical
passenger vehicle tire size.

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Passenger (P-Metric) Tire
(1) Passenger (P-Metric) Tire:
The United States version of a
metric tire sizing system. The
letter "P" as the first character in
the tire size means a passenger
vehicle tire engineered to
standards set by the U.S. Tire and
Rim Association.
(2) Tire Width
:The 3-digit
number indicates the tire section
width in millimeters from sidewall
to sidewall.
(3) Aspect Ratio
:A 2-digit
number that indicates the tire
height-to-width measurements.
For example, if the tire size aspect
ratio is 75, as shown in item (3) of the illustration, it would mean
that the tire's sidewall is
75 percent as high as it is wide.
(4) Construction Code
:A letter
code is used to indicate the type
of ply construction in the tire. The
letter "R" means radial ply
construction; the letter "D" means
diagonal or bias ply construction.
(5) Rim Diameter
:Diameter of
the wheel in inches.
(6) Service Description
:These
characters represent the load
index and speed rating of the tire.
The load index represents the load
carrying capacity a tire is certified
to carry. The speed rating is the
maximum speed a tire is certified
to carry a load.
Tire Terminology and
Definitions
Air Pressure:The amount of air
inside the tire pressing outward
on each square inch of the tire. Air pressure is expressed in kPa
(kilopascal) or psi (pounds per
square inch).
Accessory Weight
:The combined
weight of optional accessories.
Some examples of optional
accessories are automatic
transmission, power windows,
power seats, and air conditioning.
Aspect Ratio
:The relationship of
a tire's height to its width.
Belt
:A rubber coated layer of
cords between the plies and the
tread. Cords may be made from
steel or other reinforcing
materials.
Bead
:The tire bead contains steel
wires wrapped by steel cords that
hold the tire onto the rim.
Bias Ply Tire
:A pneumatic tire in
which the plies are laid at
alternate angles less than
90 degrees to the centerline of the
tread.

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vehicle. The side of the tire that
contains a whitewall, bears white
lettering, or bears manufacturer,
brand, and/or model name
molding that is higher or deeper
than the same moldings on the
other sidewall of the tire.
Passenger (P-Metric) Tire
:A tire
used on passenger cars and some
light duty trucks and
multipurpose vehicles.
Recommended Inf lation
Pressure
:Vehicle manufacturer's
recommended tire inflation
pressure as shown on the tire
placard. See Tire Pressure 0343
and
Vehicle Load Limits 0228.
Radial Ply Tire
:A pneumatic tire
in which the ply cords that extend
to the beads are laid at 90 degrees
to the centerline of the tread.
Rim
:A metal support for a tire
and upon which the tire beads are
seated. Sidewall
:The portion of a tire
between the tread and the bead.
Speed Rating
:An alphanumeric
code assigned to a tire indicating
the maximum speed at which a
tire can operate.
Traction
:The friction between
the tire and the road surface. The
amount of grip provided.
Tread
:The portion of a tire that
comes into contact with the road.
Treadwear Indicators
:Narrow
bands, sometimes called wear
bars, that show across the tread of
a tire when only 1.6 mm (1/16 in)
of tread remains. See When It Is
Time for New Tires 0352.
UTQGS (Uniform Tire Quality
Grading Standards)
:A tire
information system that provides
consumers with ratings for a tire's
traction, temperature, and
treadwear. Ratings are determined
by tire manufacturers using
government testing procedures. The ratings are molded into the
sidewall of the tire. See
Uniform
Tire Quality Grading 0354.
Vehicle Capacity Weight
:The
number of designated seating
positions multiplied by
68 kg (150 lb) plus the rated cargo
load. See Vehicle Load Limits 0228.
Vehicle Maximum Load on the
Tire
:Load on an individual tire
due to curb weight, accessory
weight, occupant weight, and
cargo weight.
Vehicle Placard
:A label
permanently attached to a vehicle
showing the vehicle capacity
weight and the original equipment
tire size and recommended
inflation pressure. See “Tire and
Loading Information Label” under
Vehicle Load Limits 0228.
Tire Pressure
Tires need the correct amount of
air pressure to operate effectively.

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TPMS sensors could be damaged
and would not be covered by the
vehicle warranty.
Tire Pressure for
High-Speed Operation
{Warning
Driving at high speeds, 160 km/h
(100 mph) or higher, puts additional
strain on tires. Sustained
high-speed driving causes excessive
heat buildup and can cause sudden
tire failure. This could cause a
crash, and you or others could be
killed. Some high-speed rated tires
require inflation pressure
adjustment for high-speed
operation. When speed limits and
road conditions allow the vehicle to
be driven at high speeds, make sure
the tires are rated for high-speed
operation, are in excellent
condition, and are set to the correct
cold tire inflation pressure for the
vehicle load.Vehicles with tire sizes listed in the
High Speed Operation Inflation
Pressures table require inflation
pressure adjustment when driving the
vehicle at speeds of 160 km/h
(100 mph) or higher. Set the cold tire
inflation pressure to the
corresponding value in the table for
the tire size on the vehicle.

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
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High Speed Operation Inf lation Pressures
Tire Size Cold Inf lation Pressure kPa (psi)
235/65R18 300 kPa (44 psi)
235/55R20 300 kPa (44 psi)
265/45R21 300 kPa (44 psi)
Return the tires to the recommended
cold tire inflation pressure when
high-speed driving has ended. See
Vehicle Load Limits 0228 and
Tire Pressure 0343.
Tire Pressure Monitor
System
The Tire Pressure Monitor System
(TPMS) uses radio and sensor
technology to check tire pressure
levels. The TPMS sensors monitor the
air pressure in your tires and transmit
tire pressure readings to a receiver
located in the vehicle.
Each tire, including the spare (if
provided), should be checked monthly
when cold and inflated to the
inflation pressure recommended by
the vehicle manufacturer on the vehicle placard or tire inflation
pressure label. (If your vehicle has
tires of a different size than the size
indicated on the vehicle placard or tire
inflation pressure label, you should
determine the proper tire inflation
pressure for those tires.)
As an added safety feature, your
vehicle has been equipped with a tire
pressure monitoring system (TPMS)
that illuminates a low tire pressure
telltale when one or more of your tires
is significantly under-inflated.
Accordingly, when the low tire
pressure telltale illuminates, you
should stop and check your tires as
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