2021 CADILLAC XT6 check engine light

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
DRIVING AND OPERATING 249
StabiliTrak/ESC activates when the
system senses a discrepancy between
the intended path and the direction
the vehicle is actually traveling.
StabiliTrak/ESC selectively applies
braking pressure at any one of the
vehicle's brakes to help steer the
vehicle in the direction which you are
steering.
If cruise control is being used and TCS
or StabiliTrak/ESC begins to limit
wheel spin, cruise control will
disengage. Cruise control may be
turned back on when road conditions
allow. TCS and StabiliTrak/ESC will
automatically turn on when cruise
control is set.
Both systems come on automatically
when the vehicle is started and begins
to move. The systems may be heard or
felt while they are operating or while
performing diagnostic checks. This is
normal and does not mean there is a
problem with the vehicle.
It is recommended to leave both
systems on for normal driving
conditions, but it may be necessary to
turn TCS off if the vehicle gets stuckin sand, mud, ice, or snow. See
If the
Vehicle Is Stuck 0228 and “Turning
the Systems Off and On ”later in this
section.
The indicator light for both systems is
in the instrument cluster. This
light will:
.Flash when TCS is limiting
wheel spin.
.Flash when StabiliTrak/ESC is
activated.
.Turn on and stay on when either
system is not working.
If either system fails to turn on or to
activate, a message may display in the
Driver Information Center (DIC), and
dcomes on and stays on to indicate
that the system is inactive and is not
assisting the driver in maintaining
control. The vehicle is safe to drive,
but driving should be adjusted
accordingly. If
dcomes on and stays on:
1. Stop the vehicle.
2. Turn the engine off and wait 15 seconds.
3. Start the engine.
Drive the vehicle. If
dcomes on and
stays on, the vehicle may need more
time to diagnose the problem. If the
condition persists, see your dealer.
Turning the Systems Off and On

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
300 DRIVING AND OPERATING
controller as part of the trailer wiring
package. The harness contains the
following circuits:Electric Trailer
Brakes Blue
Battery Feed Red/Black or
Red/Blue
Brake Apply
Signal White/Blue
Ground Black or White
Refer to the aftermarket electric trailer
brake controller owner's manual to
determine wire color coding of the
electric trailer brake controller. The
wire colors on the brake controller
may be different from the vehicle.
It may be necessary to have a
technician connect the 12-volt power
to the engine compartment fuse block.
The electric trailer brake controller
should be installed by your dealer or a
qualified service center.
Trailer Lamps
Always check that 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 should 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. Trailer
sway 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
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 pedal. 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 0248.
{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
(Continued)

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
DRIVING AND OPERATING 301
Warning (Continued)
causes, including an improperly or
overloaded trailer, unrestrained
cargo, improper trailer hitch
configuration, or improperly
inflated or incorrect vehicle or
trailer tires. SeeTowing Equipment
0 297 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.
Always check all trailer tire pressures
before each trip when the tires are
cool. Low trailer tire pressure is a
leading cause of trailer tire blowouts. Trailer tires deteriorate over time. The
trailer tire sidewall will show the week
and year the tire was manufactured.
Many trailer tire manufacturers
recommend replacing tires more than
six years old.
Overloading is another leading cause
of trailer tire blowouts. Never load the
trailer with more weight than the tires
are designed to support. The load
rating is on the trailer tire sidewall.
Always know the maximum speed
rating for the trailer tires before
driving. This may be significantly
lower than the vehicle tire speed
rating. The speed rating may be on
the trailer tire sidewall. If the speed
rating is not shown, the default trailer
tire speed rating is 105 km/h (65 mph).
Conversions and
Add-Ons
Add-On Electrical
Equipment
{Warning
The Data Link Connector (DLC) is
used for vehicle service and
Emission Inspection/Maintenance
testing. See
Malfunction Indicator
Lamp (Check Engine Light) 0115.
A device connected to the DLC —
such as an aftermarket fleet or
driver-behavior tracking device —
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.

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
VEHICLE CARE 303
Vehicle Care
General Information
General Information . . . . . . . . . . . . . 304
California Proposition65 Warning . . . . . . . . . . . . . . . . . . . . . 304
California Perchlorate Materials Requirements . . . . . . . . . . . . . . . . . . . 305
Accessories and Modifications . . . . . . . . . . . . . . . . . . . 305
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . . . . . . 305
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 306
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . . . . . . 308
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . 311
Engine Oil Life System . . . . . . . . . . . 313
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314
Engine Air Filter Life System . . . . 314
Engine Air Cleaner/Filter . . . . . . . . . 315
Cooling System . . . . . . . . . . . . . . . . . . . 316
Engine Overheating . . . . . . . . . . . . . . 320
Washer Fluid . . . . . . . . . . . . . . . . . . . . . 321
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . 322 Battery - North America . . . . . . . . . 323
All-Wheel Drive . . . . . . . . . . . . . . . . . . 324
Park Brake and P (Park)
Mechanism Check . . . . . . . . . . . . . . 324
Wiper Blade Replacement . . . . . . . 325
Windshield Replacement . . . . . . . . 326
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . 326
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . 327
Bulb Replacement
LED Lighting . . . . . . . . . . . . . . . . . . . . . 327
Electrical System
Electrical System Overload . . . . . . 327
Fuses and Circuit Breakers . . . . . . 328
Engine Compartment Fuse
Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
Instrument Panel Fuse Block . . . . 332
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
All-Season Tires . . . . . . . . . . . . . . . . . . 337
Winter Tires . . . . . . . . . . . . . . . . . . . . . . 338
Summer Tires . . . . . . . . . . . . . . . . . . . . 338
Tire Sidewall Labeling . . . . . . . . . . . 339 Tire Designations . . . . . . . . . . . . . . . . . 340
Tire Terminology and
Definitions . . . . . . . . . . . . . . . . . . . . . . 341
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . 343
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . . . . . . 345
Tire Pressure Monitor System . . . 346
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . . . . . . 347
Tire Inspection . . . . . . . . . . . . . . . . . . . 350
Tire Rotation . . . . . . . . . . . . . . . . . . . . . 351
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352
Buying New Tires . . . . . . . . . . . . . . . . 353
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . . . . . 354
Uniform Tire Quality Grading . . . 354
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . . . . . . 356
Wheel Replacement . . . . . . . . . . . . . . 356
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . 356
If a Tire Goes Flat . . . . . . . . . . . . . . . . 357
Tire Changing . . . . . . . . . . . . . . . . . . . . . 358
Compact Spare Tire . . . . . . . . . . . . . . 364
Jump Starting
Jump Starting - North America . . . . . . . . . . . . . . . . . . . . . . . . . 364

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
VEHICLE CARE 321
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.

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
366 VEHICLE CARE
The discharged battery positive (+)
terminal is under a cover. Remove the
cover to expose the terminal.1. Check the other vehicle. It must have a 12-volt battery with a
negative ground system.
Caution
If the other vehicle does not have a
12-volt system with a negative
ground, both vehicles can be
damaged. Only use a vehicle that
has a 12-volt system with a
negative ground for jump starting.
2. Position the two vehicles so that they are not touching.
3. Set the parking brake firmly and put the transmission in P (Park).
See Shifting Into Park 0237.
Caution
If any accessories are left on or
plugged in during the jump starting
procedure, they could be damaged.
The repairs would not be covered
by the vehicle warranty. Whenever
(Continued)
Caution (Continued)
possible, turn off or unplug all
accessories on either vehicle when
jump starting.
4. Turn the ignition off. Turn off all lights and accessories in both
vehicles, except the hazard warning
flashers if needed.
{Warning
An electric fan can start up even
when the engine is not running and
can injure you. Keep hands,
clothing, and tools away from any
underhood electric fan.
{Warning
Using a match near a battery can
cause battery gas to explode. People
have been hurt doing this, and
some have been blinded. Use a
flashlight if you need more light.
(Continued)
Warning (Continued)
Battery fluid contains acid that can
burn you. Do not get it on you.
If you accidentally get it in your
eyes or on your skin, flush the place
with water and get medical help
immediately.
{Warning
Fans or other moving engine parts
can injure you badly. Keep your
hands away from moving parts
once the engine is running.
5. Connect one end of the red positive (+) cable to the discharged
battery positive (+) terminal.
6. Connect the other end of the red positive (+) cable to the good
battery positive (+) terminal.
7. Connect one end of the black negative (–) cable to the good
battery negative (–) terminal.
8. Connect the other end of the black negative (–) cable to the discharged
negative (–) grounding point.

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
372 VEHICLE CARE
.Use a nonabrasive wax on the
vehicle after washing to protect and
extend the molding finish.
Cleaning Exterior Lamps/Lenses,
Emblems, Decals, and Stripes
Use only lukewarm or cold water, a
soft cloth, and a car washing soap to
clean exterior lamps, lenses, emblems,
decals, and stripes. Follow instructions
under "Washing the Vehicle"
previously in this section.
Lamp covers are made of plastic, and
some have a UV protective coating. Do
not clean or wipe them when dry.
Do not use any of the following on
lamp covers:
.Abrasive or caustic agents.
.Washer fluids and other cleaning
agents in higher concentrations
than suggested by the manufacturer.
.Solvents, alcohols, fuels, or other
harsh cleaners.
.Ice scrapers or other hard items.
.Aftermarket appearance caps or
covers while the lamps are
illuminated, due to excessive heat
generated.
Caution
Failure to clean lamps properly can
cause damage to the lamp cover
that would not be covered by the
vehicle warranty.
Caution
Using wax on low gloss black finish
stripes can increase the gloss level
and create a non-uniform finish.
Clean low gloss stripes with soap
and water only.
Air Intakes
Clear debris from the air intakes,
between the hood and windshield,
when washing the vehicle.
Shutter System
The vehicle may have a shutter
system designed to help improve fuel
economy. Keep the shutter system
clear of debris, snow and ice. If the
check engine light is activated, please
check to see if the shutter system is
clear of debris, snow or ice.
Windshield and Wiper Blades
Clean the outside of the windshield
with glass cleaner.
Clean rubber blades using a lint-free
cloth or paper towel soaked with
windshield washer fluid or a mild
detergent. Wash the windshield

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
SERVICE AND MAINTENANCE 387
.Trained dealer technicians have the
diagnostic equipment to test the
battery and ensure that the
connections and cables are
corrosion-free.
Belts
.Belts may need replacing if they
squeak or show signs of cracking or
splitting.
.Trained dealer technicians have
access to tools and equipment to
inspect the belts and recommend
adjustment or replacement when
necessary.
Brakes
Brakes stop the vehicle and are crucial
to safe driving.
.Signs of brake wear may include
chirping, grinding, or squealing
noises, or difficulty stopping.
.Trained dealer technicians have
access to tools and equipment to
inspect the brakes and recommend
quality parts engineered for the
vehicle. Fluids
Proper fluid levels and approved fluids
protect the vehicle’s systems and
components. See
Recommended Fluids
and Lubricants 0389 for GM approved
fluids.
.Engine oil and windshield washer
fluid levels should be checked at
every fuel fill.
.Instrument cluster lights may come
on to indicate that fluids may be
low and need to be filled.
Hoses
Hoses transport fluids and should be
regularly inspected to ensure that
there are no cracks or leaks. With a
multi-point inspection, your dealer
can inspect the hoses and advise if
replacement is needed.
Lamps
Properly working headlamps,
taillamps, and brake lamps are
important to see and be seen on
the road.
.Signs that the headlamps need
attention include dimming, failure
to light, cracking, or damage. The brake lamps need to be checked
periodically to ensure that they light
when braking.
.With a multi-point inspection, your
dealer can check the lamps and
note any concerns.
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;