2021 CADILLAC XT4 check engine light

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
14584367) - 2021 - CRC - 10/14/20
212 DRIVING AND OPERATING
Caution
Do not drive through standing
water if it is deep enough to cover
the wheel hubs, axles, or exhaust
pipe. Deep water can damage the
axle and other vehicle parts.
If the standing water is not too deep,
drive through it slowly. At faster
speeds, water can get into the engine
and cause it to stall. Stalling can
occur if the exhaust pipe is under
water. Do not turn off the ignition
when driving through water. If the
exhaust pipe is under water, the
engine will not start. When going
through water, the brakes get wet and
it may take longer to stop. See Driving
on Wet Roads 0212.
After Off-Road Driving
Remove any brush or debris that has
collected on the underbody or chassis,
or under the hood. These
accumulations can be a fire hazard.
After operation in mud or sand, have
the brake linings cleaned and checked.
These substances can cause glazing
and uneven braking. Check the body structure, steering, suspension,
wheels, tires, and exhaust system for
damage and check the fuel lines and
cooling system for any leakage.
More frequent maintenance service is
required. See
Maintenance Schedule
0 358.
Driving on Wet Roads
Rain and wet roads can reduce vehicle
traction and affect your ability to stop
and accelerate. Always drive slower in
these types of driving conditions and
avoid driving through large puddles
and deep-standing or flowing water.
{Warning
Wet brakes can cause crashes. They
might not work as well in a quick
stop and could cause pulling to one
side. You could lose control of the
vehicle.
After driving through a large puddle
of water or a car/vehicle wash,
lightly apply the brake pedal until
the brakes work normally.
(Continued)
Warning (Continued)
Flowing or rushing water creates
strong forces. Driving through
flowing water could cause the
vehicle to be carried away. If this
happens, you and other vehicle
occupants could drown. Do not
ignore police warnings and be very
cautious about trying to drive
through flowing water.
Hydroplaning
Hydroplaning is dangerous. Water can
build up under the vehicle's tires so
they actually ride on the water. This
can happen if the road is wet enough
and you are going fast enough. When
the vehicle is hydroplaning, it has
little or no contact with the road.
There is no hard and fast rule about
hydroplaning. The best advice is to
slow down when the road is wet.
Other Rainy Weather Tips
Besides slowing down, other wet
weather driving tips include:
.Allow extra following distance.

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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DRIVING AND OPERATING 235
R (Reverse). The vehicle must come to
a complete stop on a grade for HSA to
activate.
Ride Control Systems
Traction Control/Electronic
Stability Control
System Operation
The vehicle has a Traction Control
System (TCS) and StabiliTrak/
Electronic Stability Control (ESC).
These systems help limit wheel spin
and assist the driver in maintaining
control, especially on slippery road
conditions.
TCS activates if it senses that any of
the drive wheels are spinning or
beginning to lose traction. On an
All-Wheel Drive (AWD) vehicle in
AWD or Sport Mode, the system will
operate if it senses that any of the
wheels are spinning or beginning to
lose traction. When this happens, TCS
applies the brakes to the spinning
wheels and reduces engine power to
limit wheel spin.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
traction control 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 0214 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.

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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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.

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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280 DRIVING AND OPERATING
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 blow-outs.
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 blow-outs. Never load
your trailer with more weight than the
tires are designed to support. The load
rating is located 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. SeeMalfunction Indicator
Lamp (Check Engine Light) 0105.
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.
Caution
Some electrical equipment can
damage the vehicle or cause
components to not work and would (Continued)
Caution (Continued)
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 064 and
Adding Equipment to the
Airbag-Equipped Vehicle 064.

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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 295
Warning (Continued)
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.
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 0285 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.
(Continued)

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VEHICLE CARE 297
The brake master cylinder reservoir is
filled with GM approved DOT 4 brake
fluid as indicated on the reservoir cap.
SeeEngine Compartment Overview
0 285 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
0 107.
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 0358.
What to Add
Use only GM approved DOT 4 brake
fluid from a clean, sealed container.
See Recommended Fluids and
Lubricants 0367.
{Warning
The wrong or contaminated brake
fluid could result in damage to the
brake system. This could result in
the loss of braking leading to a
possible injury. Always use the
proper GM approved brake fluid.
Caution
If brake fluid is spilled on the
vehicle's painted surfaces, the paint
finish can be damaged. Immediately
wash off any painted surface.
Battery - North America
The original equipment battery is
maintenance free. Do not remove the
cap and do not add fluid.
Refer to the replacement number
shown on the original battery label
when a new battery is needed. See
Engine Compartment Overview 0285
for battery location.

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
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350 VEHICLE CARE
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 systemclear 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
thoroughly when cleaning the blades.
Bugs, road grime, sap, and a buildup
of vehicle wash/wax treatments may
cause wiper streaking.
Replace the wiper blades if they are
worn or damaged. Damage can be
caused by extreme dusty conditions,
sand, salt, heat, sun, snow, and ice.
Weatherstrips
Apply weatherstrip lubricant on
weatherstrips to make them last
longer, seal better, and not stick or
squeak. Lubricate weatherstrips at
least once a year. Hot, dry climates
may require more frequent
application. Black marks from rubber