2021 CADILLAC CT4 oil change

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
294 DRIVING AND OPERATING
Recommended Fuel (L3B
2.7L L4 Turbo Engine)
Use premium unleaded gasoline
meeting ASTM specification D4814
with a posted octane rating of 93—
(R+M)/2. If unavailable, unleaded
gasoline with a posted octane rating
of 91 may be used, but with reduced
performance and fuel economy. If the
octane is less than 91, the engine
could be damaged and the repairs
would not be covered by the vehicle
warranty. If heavy knocking is heard
when using gasoline rated at
93 octane, the engine needs service.
Do not use any fuel labeled E85 or
FlexFuel. Do not use gasoline with
ethanol levels greater than 15% by
volume.
Prohibited Fuels
Caution
Do not use fuels with any of the
following conditions; doing so may
damage the vehicle and void its
warranty:
.For vehicles that are not
FlexFuel, fuel labeled greater
than 15% ethanol by volume,
such as mid-level ethanol blends
(16–50% ethanol), E85,
or FlexFuel.
.Fuel with any amount of
methanol, methylal, ferrocene,
and aniline. These fuels can
corrode metal fuel system parts
or damage plastic and rubber
parts.
.Fuel containing metals such as
methylcyclopentadienyl
manganese tricarbonyl (MMT),
which can damage the emissions
control system and spark plugs.
.Fuel with a posted octane rating
of less than the recommended
fuel. Using this fuel will lower
(Continued)
Caution (Continued)
fuel economy and performance,
and may decrease the life of the
emissions catalyst.
Fuels in Foreign Countries
The U.S., Canada, and Mexico post
fuel octane ratings in anti-knock index
(AKI). For fuel not to use in a foreign
country, seeProhibited Fuels 0294.
Fuel Additives
TOP TIER Detergent Gasoline is highly
recommended for use with your
vehicle. If your country does not have
TOP TIER Detergent Gasoline, add
ACDelco Fuel System Treatment
Plus−Gasoline to the vehicle’s gasoline
fuel tank at every oil change or
15 000 km (9,000 mi), whichever
occurs first. TOP TIER Detergent
Gasoline and ACDelco Fuel System
Treatment Plus−Gasoline will help
keep your vehicle’s engine fuel deposit
free and performing optimally.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
298 DRIVING AND OPERATING
.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. SeeManual Mode
(Electronic Shifter) 0235 or
Manual Mode (Mechanical Shifter)
0 234.
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:
.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.
.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.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
312 VEHICLE CARE
9. Brake Fluid Reservoir. SeeBrake
Fluid 0325.
10. Remote Negative (-) Battery Terminal. See Jump Starting - North
America 0366.
11. Engine Compartment Fuse Block. See Engine Compartment Fuse Block
0 332.
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 0314.
.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 0309 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.
.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

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
314 VEHICLE CARE
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 might 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 servicepeople 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.
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 buttons, display REMAINING OIL LIFE on the DIC.
See Driver Information Center (DIC)
(Base Level) 0107 or
Driver Information Center (DIC)
(Uplevel) 0110.
2. Press and hold the thumbwheel on the steering wheel. When the
confirmation message displays,
select YES. The oil life will change
to 100%.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
VEHICLE CARE 315
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 oil life system can also be reset as
follows: 1. Using the DIC buttons, display REMAINING OIL LIFE on the DIC.
See Driver Information Center (DIC)
(Base Level) 0107 or
Driver Information Center (DIC)
(Uplevel) 0110.
2. Fully press and release the accelerator pedal three times
within five seconds.
If the CHANGE ENGINE OIL SOON
message is not on, the system is
reset.
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
How to Check Automatic
Transmission Fluid
It is not necessary to check the
transmission fluid level.
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.
The vehicle is not equipped with a
transmission fluid level dipstick.
There is a special procedure for
checking and changing the
transmission fluid. Because this
procedure is difficult, this should be
done at the dealer. Contact your dealer
for additional information.
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 (Continued)
Caution (Continued)
transmission fluid. See
Recommended Fluids and Lubricants
0391.
Change the fluid and filter at the
intervals listed in Maintenance
Schedule 0380, and be sure to use the
fluid listed in Recommended Fluids and
Lubricants 0391.
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 the 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.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
VEHICLE CARE 319
Caution
Do not use anything other than a
mix of DEX-COOL coolant that
meets GM Standard GMW3420 and
clean, drinkable water. Anything
else can cause damage to the
engine cooling system and the
vehicle, which would not be covered
by the vehicle warranty.
Never dispose of engine coolant by
putting it in the trash, pouring it on
the ground, or into sewers, streams,
or bodies of water. Have the coolant
changed by an authorized service
center, familiar with legal
requirements regarding used coolant
disposal. This will help protect the
environment and your health.
Checking Coolant
The vehicle must be on a level surface
when checking the coolant level.
It is normal to see coolant moving in
the upper coolant hose return line
when the engine is running. It is also
normal to see bubbles entering the
surge tank through the small hose. 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 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.
If no coolant is visible in the coolant
surge tank, add coolant as follows:
How to Add Coolant to the
Coolant 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
Plain water, or other liquids such as
alcohol, can boil before the proper
coolant mixture will. With plain
water or the wrong mixture, the
engine could get too hot but there
would not be an overheat warning.
The engine could catch fire and you
or others could be burned.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
SERVICE AND MAINTENANCE 379
Service and
Maintenance
General Information
General Information . . . . . . . . . . . . . 379
Maintenance Schedule
Maintenance Schedule . . . . . . . . . . . 380
Special Application Services
Special Application Services . . . . . 388
Additional Maintenance
and Care
Additional Maintenanceand Care . . . . . . . . . . . . . . . . . . . . . . . . . 388
Recommended Fluids,
Lubricants, and Parts
Recommended Fluids andLubricants . . . . . . . . . . . . . . . . . . . . . . . 391
Maintenance Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 392
Maintenance Records
Maintenance Records . . . . . . . . . . . . 394
General Information
Your vehicle is an important
investment. This section describes the
required maintenance for the vehicle.
Follow this schedule to help protect
against major repair expenses
resulting from neglect or inadequate
maintenance. It may also help to
maintain the value of the vehicle if it
is sold. It is the responsibility of the
owner to have all required
maintenance performed.
Your dealer has trained technicians
who can perform required
maintenance using genuine
replacement parts. They have
up-to-date tools and equipment for
fast and accurate diagnostics. Many
dealers have extended evening and
Saturday hours, courtesy
transportation, and online scheduling
to assist with service needs.
Your dealer recognizes the importance
of providing competitively priced
maintenance and repair services. With
trained technicians, the dealer is the
place for routine maintenance such as
oil changes and tire rotations and additional maintenance items like
tires, brakes, batteries, and wiper
blades.
Caution
Damage caused by improper
maintenance can lead to costly
repairs and may not be covered by
the vehicle warranty. Maintenance
intervals, checks, inspections,
recommended fluids, and lubricants
are important to keep the vehicle in
good working condition.
Do not have chemical flushes that
are not approved by GM performed
on the vehicle. The use of flushes,
solvents, cleaners, or lubricants that
are not approved by GM could
damage the vehicle, requiring
expensive repairs that are not
covered by the vehicle warranty.
The Tire Rotation and Required
Services are the responsibility of the
vehicle owner. It is recommended to
have your dealer perform these
services every 12 000 km/7,500 mi.
Proper vehicle maintenance helps to

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
380 SERVICE AND MAINTENANCE
keep the vehicle in good working
condition, improves fuel economy, and
reduces vehicle emissions.
Because of the way people use
vehicles, maintenance needs vary.
There may need to be more frequent
checks and services. The Additional
Required Services - Normal are for
vehicles that:
.Carry passengers and cargo within
recommended limits on the Tire
and Loading Information label. See
Vehicle Load Limits0214.
.Are driven on reasonable road
surfaces within legal driving limits.
.Use the recommended fuel. See
Recommended Fuel (LSY 2.0L L4
Turbo Engine) 0293 or
Recommended Fuel (L3B 2.7L L4
Turbo Engine) 0294.
Refer to the information in the
Maintenance Schedule Additional
Required Services - Normal chart. The Additional Required Services -
Severe are for vehicles that are:
.Mainly driven in heavy city traffic
in hot weather.
.Mainly driven in hilly or
mountainous terrain.
.Used for high speed or competitive
driving.
.Used for taxi, police, or delivery
service.
Refer to the information in the
Maintenance Schedule Additional
Required Services - Severe chart.
{Warning
Performing maintenance work can
be dangerous and can cause serious
injury. Perform maintenance work
only if the required information,
proper tools, and equipment are
available. If they are not, see your
dealer to have a trained technician
do the work. See Doing Your Own
Service Work 0306.
Maintenance Schedule
Owner Checks and Services
Check the engine oil level. See Engine
Oil 0312.
Once a Month
.Check the tire inflation pressures.
See Tire Pressure 0346.
.Inspect the tires for wear. See Tire
Inspection 0352.
.Check the windshield washer fluid
level. See Washer Fluid 0323.
Engine Oil Change
When the CHANGE ENGINE OIL
SOON message displays, have the
engine oil and filter changed within
the next 1 000 km (600 mi ). If driven
under the best conditions, the engine
oil life system may not indicate the
need for vehicle service for up to a
year. The engine oil and filter must be
changed at least once a year and the