2020 CADILLAC XT4 check engine

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13527548) - 2020 - CRC - 9/5/19
238 DRIVING AND OPERATING
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 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. 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
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 enginetorque to help slow the vehicle. TSC
will not function if StabiliTrak/ESC is
turned off. See
Traction Control/
Electronic Stability Control 0191.
{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
0 236 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

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13527548) - 2020 - CRC - 9/5/19
DRIVING AND OPERATING 239
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 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. 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 XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13527548) - 2020 - CRC - 9/5/19
VEHICLE CARE 241
Vehicle Care
General Information
General Information . . . . . . . . . . . . . 242
California Proposition65 Warning . . . . . . . . . . . . . . . . . . . . . 242
California Perchlorate Materials Requirements . . . . . . . . . . . . . . . . . . . 243
Accessories and Modifications . . . . . . . . . . . . . . . . . . . 243
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . . . . . . 243
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . . . . . . 246
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . 247
Engine Oil Life System . . . . . . . . . . . 249
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250
Engine Air Filter Life System . . . . 250
Engine Air Cleaner/Filter . . . . . . . . . 251
Cooling System . . . . . . . . . . . . . . . . . . . 252
Engine Overheating . . . . . . . . . . . . . . 255
Washer Fluid . . . . . . . . . . . . . . . . . . . . . 256
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . 258
Battery - North America . . . . . . . . . 259 All-Wheel Drive . . . . . . . . . . . . . . . . . . 260
Starter Switch Check . . . . . . . . . . . . . 260
Park Brake and P (Park)
Mechanism Check . . . . . . . . . . . . . . 260
Wiper Blade Replacement . . . . . . . 261
Windshield Replacement . . . . . . . . 262
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . 262
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . 263
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . 264
LED Lighting . . . . . . . . . . . . . . . . . . . . . 264
Front Turn Signal Lamps . . . . . . . . 264
Back-Up Lamps . . . . . . . . . . . . . . . . . . . 264
Electrical System
Electrical System Overload . . . . . . 265
Fuses and Circuit Breakers . . . . . . 265
Engine Compartment Fuse
Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
Instrument Panel Fuse Block . . . . 269
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272
All-Season Tires . . . . . . . . . . . . . . . . . . 273
Winter Tires . . . . . . . . . . . . . . . . . . . . . . 273
Summer Tires . . . . . . . . . . . . . . . . . . . . 273
Tire Sidewall Labeling . . . . . . . . . . . 274
Tire Designations . . . . . . . . . . . . . . . . . 276 Tire Terminology and
Definitions . . . . . . . . . . . . . . . . . . . . . . 276
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . 279
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . . . . . . 280
Tire Pressure Monitor System . . . 281
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . . . . . . 281
Tire Inspection . . . . . . . . . . . . . . . . . . . 285
Tire Rotation . . . . . . . . . . . . . . . . . . . . . 286
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
Buying New Tires . . . . . . . . . . . . . . . . 287
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . . . . . 289
Uniform Tire Quality Grading . . . 289
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . . . . . . 291
Wheel Replacement . . . . . . . . . . . . . . 291
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . 292
If a Tire Goes Flat . . . . . . . . . . . . . . . . 292
Tire Sealant and Compressor Kit . . . . . . . . . . . . . . . . . 293
Storing the Tire Sealant and Compressor Kit . . . . . . . . . . . . . . . . . 300
Tire Changing . . . . . . . . . . . . . . . . . . . . . 300
Compact Spare Tire . . . . . . . . . . . . . . 305
Jump Starting
Jump Starting - North America . . . . . . . . . . . . . . . . . . . . . . . . . 306

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13527548) - 2020 - CRC - 9/5/19
VEHICLE CARE 247
1.Engine Air Cleaner/Filter 0251.
2. Engine Oil Fill Cap. See Engine Oil
0 247.
3. Engine Oil Dipstick. See Engine
Oil 0247.
4. Engine Cooling Fan (Out of View). See Cooling System 0252.
5. Brake Fluid Reservoir. See Brake
Fluid 0258.
6. Battery - North America 0259.
7. Engine Coolant Surge Tank and Pressure Cap. See Cooling System
0 252.
8. Positive (+) Battery Terminal (Under Cover). See Jump Starting
- North America 0306.
9. Windshield Washer Fluid Reservoir. See Washer Fluid
0 256.
10. Engine Compartment Fuse Block
0266.
11. Remote Negative (-) Battery Terminal. See Jump Starting -
North America 0306.Engine Oil
To ensure proper engine performance
and long life, careful attention must
be paid to engine oil. Following these
simple, but important steps will help
protect your investment:
.
Use engine oil approved to the
proper specification and of the
proper viscosity grade. See
“Selecting the Right Engine Oil” in
this section.
. Check the engine oil level regularly
and maintain the proper oil level.
See “Checking Engine Oil” and
“When to Add Engine Oil” in this
section.
. Change the engine oil at the
appropriate time. See Engine Oil
Life System 0249.
. Always dispose of engine oil
properly. See “What to Do with
Used Oil” in this section.
Checking Engine Oil
Check the engine oil level regularly,
every 650 km (400 mi), especially prior
to a long trip. The engine oil dipstick handle is a loop. See
Engine
Compartment Overview 0246 for the
location.
{Warning
The engine oil dipstick handle may
be hot; it could burn you. Use a
towel or glove to touch the dipstick
handle.
If a low oil Driver Information Center
(DIC) message displays, check the oil
level.
Follow these guidelines:
. To get an accurate reading, park
the vehicle on level ground. Check
the engine oil level after the
engine has been off for at least
two hours. Checking the engine oil
level on steep grades or too soon
after engine shutoff can result in
incorrect readings. Accuracy
improves when checking a cold
engine prior to starting. Remove
the dipstick and check the level.

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13527548) - 2020 - CRC - 9/5/19
248 VEHICLE CARE
.If unable to wait two hours, the
engine must be off for at least
15 minutes if the engine is warm,
or at least 30 minutes if the
engine is not warm. Pull out the
dipstick, wipe it with a clean paper
towel or cloth, then push it back
in all the way. Remove it again,
keeping the tip down, and check
the level.
When to Add Engine Oil
If the oil is below the cross-hatched
area at the tip of the dipstick and the
engine has been off for at least
15 minutes, add 1 L (1 qt) of the
recommended oil and then recheck
the level. See “Selecting the Right
Engine Oil” later in this section for an
explanation of what kind of oil to use.
For engine oil crankcase capacity, see
Capacities and Specifications 0333.
Caution
Do not add too much oil. Oil levels
above or below the acceptable
operating range shown on the
dipstick are harmful to the engine.
If the oil level is above the
operating range (i.e., the engine has
so much oil that the oil level gets
above the cross-hatched area that
shows the proper operating range),
the engine could be damaged. Drain
the excess oil or limit driving of the
vehicle, and seek a service
professional to remove the
excess oil.
See Engine Compartment Overview
0 246 for the location of the engine oil
fill cap.
Add enough oil to put the level
somewhere in the proper operating
range. Push the dipstick all the way
back in when through.
Selecting the Right Engine Oil
Selecting the right engine oil depends
on both the proper oil specification
and viscosity grade. See Recommended
Fluids and Lubricants 0329.
Specification
Use full synthetic engine oils that
meet the dexos1 specification.
Engine oils that have been approved
by GM as meeting the dexos1
specification are marked with the
dexos1 approved logo. See
www.gmdexos.com.
Caution
Failure to use the recommended
engine oil or equivalent can result
in engine damage not covered by
the vehicle warranty.

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13527548) - 2020 - CRC - 9/5/19
VEHICLE CARE 249
Viscosity Grade
Use SAE 0W-20 viscosity grade
engine oil.
When selecting an oil of the
appropriate viscosity grade, it is
recommended to select an oil of the
correct specification. See
“Specification”earlier in this section.
Engine Oil Additives/Engine Oil
Flushes
Do not add anything to the oil. The
recommended oils meeting the dexos1
specification are all that is needed for
good performance and engine
protection.
Engine oil system flushes are not
recommended and could cause engine
damage not covered by the vehicle
warranty.
What to Do with Used Oil
Used engine oil contains certain
elements that can be unhealthy for
your skin and could even cause
cancer. Do not let used oil stay on
your skin for very long. Clean your
skin and nails with soap and water, or a good hand cleaner. Wash or
properly dispose of clothing or rags
containing used engine oil. See the
manufacturer's warnings about the
use and disposal of oil products.
Used oil can be a threat to the
environment. If you change your own
oil, be sure to drain all the oil from
the filter before disposal. Never
dispose of oil by putting it in the trash
or pouring it on the ground, into
sewers, or into streams or bodies of
water. Recycle it by taking it to a place
that collects used oil.
Engine Oil Life System
When to Change Engine Oil
This vehicle has a computer system
that indicates when to change the
engine oil and filter. This is based on a
combination of factors which include
engine revolutions, engine
temperature, and miles driven. Based
on driving conditions, the mileage at
which an oil change is indicated can
vary considerably. For the oil life
system to work properly, the system
must be reset every time the oil is
changed.
When the system has calculated that
oil life has been diminished, it
indicates that an oil change is
necessary. A CHANGE ENGINE OIL
SOON message comes on. Change the
oil as soon as possible within the next
1 000 km (600 mi). It is possible that,
if driving under the best conditions,
the oil life system may indicate that
an oil change is not necessary for up
to a year. The engine oil and filter
must be changed at least once a year
and at this time the system must be
reset. Your dealer has trained service
people who will perform this work and
reset the system. It is also important
to check the oil regularly over the
course of an oil drain interval and
keep it at the proper level.
If the system is ever reset accidentally,
the oil must be changed at 5 000 km
(3,000 mi) since the last oil change.
Remember to reset the oil life system
whenever the oil is changed.

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13527548) - 2020 - CRC - 9/5/19
250 VEHICLE CARE
How to Reset the Engine Oil Life
System
Reset the system whenever the engine
oil is changed so that the system can
calculate the next engine oil change.
To reset the system:1. Using the DIC controls on the right side of the steering wheel,
display REMAINING OIL LIFE on
the DIC. See Driver Information
Center (DIC) 0124. When
remaining oil life is low, the
CHANGE ENGINE OIL SOON
message will appear on the
display.
2. Press
Von the DIC controls and
hold down for a few seconds to
clear the CHANGE ENGINE OIL
SOON message and reset the oil
life at 100%.
Be careful not to reset the oil life
display accidentally at any time
other than after the oil is
changed. It cannot be reset
accurately until the next oil
change. The system is reset when the
CHANGE ENGINE OIL SOON message
is off.
If the CHANGE ENGINE OIL SOON
message comes back on when the
vehicle is started, the engine oil life
system has not been reset. Repeat the
procedure.
Automatic Transmission
Fluid
A transmission fluid leak is the only
reason for fluid loss. If a leak occurs,
take the vehicle to your dealer and
have it repaired as soon as possible.
Caution
Use of the incorrect automatic
transmission fluid may damage the
vehicle, and the damage may not be
covered by the vehicle warranty.
Always use the correct automatic
transmission fluid. See
Recommended Fluids and Lubricants
0
329. See your dealer to have the fluid and
filter changed at the intervals listed in
the
Maintenance Schedule 0319.
Engine Air Filter Life
System
If equipped, this feature provides the
engine air filter's remaining life and
best timing for a change. The timing
to change an engine air filter depends
on driving and environmental
conditions.
When to Change Engine Air
Filter
When the Driver Information Center
(DIC) displays a message to replace
the engine air filter at the next oil
change, follow this timing.
When the DIC displays a message to
replace the engine air filter soon,
replace the engine air filter at the
earliest convenience. The system must
be reset after the engine air filter is
changed.
If the DIC displays a message to check
the engine air filter system, see your
dealer.

Cadillac XT4 Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
13527548) - 2020 - CRC - 9/5/19
252 VEHICLE CARE
{Warning
Operating the engine with the air
cleaner/filter off can cause you or
others to be burned. Use caution
when working on the engine. Do
not start the engine or drive the
vehicle with the air cleaner/filter
off, as flames may be present if the
engine backfires.
Caution
If the air cleaner/filter is off, dirt
can easily get into the engine,
which could damage it. Always have
the air cleaner/filter in place when
driving.
Cooling System
The cooling system allows the engine
to maintain the correct working
temperature.
1. Electric Engine Cooling Fan(Out of View)
2. Coolant Surge Tank and Pressure Cap
{Warning
An underhood electric fan can start
up even when the engine is not
running and can cause injury. Keep
hands, clothing, and tools away
from any underhood electric fan.
{Warning
Do not touch heater or radiator
hoses, or other engine parts. They
can be very hot and can burn you.
Do not run the engine if there is a
leak; all coolant could leak out.
That could cause an engine fire and
can burn you. Fix any leak before
driving the vehicle.
Engine Coolant
The engine cooling system in the
vehicle is filled with DEX-COOL engine
coolant mixture. This coolant needs to
be checked and changed at
appropriate levels. See Recommended
Fluids and Lubricants 0329 and
Maintenance Schedule 0319.
The following explains the cooling
system and how to check and add
coolant when it is low. If there is a
problem with engine overheating, see
Engine Overheating 0255.