
Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Vehicle Care 381
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 atwhich 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
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.
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) 0129 or
Driver Information Center
(DIC) (Uplevel) 0132.
2. Press and hold the thumbwheel on the
steering wheel. When the

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
382 Vehicle Care
confirmation message
displays, select YES. The
oil life will change to 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 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) 0129 or
Driver Information Center
(DIC) (Uplevel) 0132.
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
transmission fluid. See
Recommended Fluids and
Lubricants
0474.
Change the fluid and filter at
the intervals listed in
Maintenance Schedule 0469,
and be sure to use the fluid
listed in Recommended Fluids
and Lubricants 0474.
Manual Transmission
Fluid
It is not necessary to check
the manual 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

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Vehicle Care 383
possible. See Recommended
Fluids and Lubricants0474
for the proper fluid to use.
Hydraulic Clutch
For vehicles with a manual
transmission, it is not
necessary to regularly check
brake/clutch fluid unless there
is a leak suspected. Adding
fluid will not correct a leak.
A fluid loss in this system
could indicate a problem. Have
the system inspected and
repaired.
When to Check and What
to Use
The brake/hydraulic clutch
fluid reservoir cap has this
symbol on it. See Engine
Compartment Overview 0373
for reservoir location. The common hydraulic clutch
and brake master cylinder fluid
reservoir is filled with brake
fluid as indicated on the
reservoir cap. See Brake Fluid
0
398 for brake fluid to use.
How to Check and Add
Fluid
Visually check the brake/
clutch fluid reservoir to make
sure the fluid level is at the
MIN (minimum) line on the side
of the reservoir. The brake/
hydraulic clutch fluid system
should be closed and sealed.
Do not remove the cap to
check the fluid level or to
top-off the fluid level. Remove
the cap only when necessary
to add the proper fluid until
the level reaches the MIN line.
Engine Air Filter Life
System
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.
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.
How to Reset the Engine
Air Filter Life System
To reset:
1. Place the vehicle in P (Park).

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
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388 Vehicle Care
.Helps keep the proper
engine temperature.
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.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Vehicle Care 461
Interior Care
To prevent dirt particle
abrasions, regularly clean the
vehicle's interior. Before using
cleaners, read and follow all
safety instructions on the
label. While cleaning the
interior, open the doors and
windows to get proper
ventilation. Newspapers or
dark garments can transfer
color to the vehicle’s interior.
Caution
Immediately remove
cleaners, hand lotions,
sunscreen, and insect
repellent from all interior
surfaces or permanent
damage may result.
Caution
Use cleaners specifically
designed for the surfaces
being cleaned to prevent
permanent damage to the(Continued)
Caution (Continued)
vehicle. Apply all cleaners
directly to a cleaning cloth.
Do not spray cleaners on
any switches or controls.
When using liquid soap
cleaners, follow the directions
on the specific cleaner or soap
solution for dilution
instructions.
Caution
To prevent damage:
.Never use a razor or any
other sharp object to
remove soil from any
interior surface
.Never use a brush with
stiff bristles.
.Never rub any surface
aggressively or with too
much pressure.
.Do not get any exposed
electrical components wet. (Continued)
Caution (Continued)
.Do not use laundry
detergents or dishwashing
soaps with degreasers. Do
not use solutions that
contain strong or
caustic soap.
.Do not heavily saturate
the upholstery when
cleaning.
.Do not use solvents or
cleaners containing
solvents.
.Do not use disinfecting
wipes that are scented or
contain bleach. Do not use
wipes or cleaners that
show a color transfer to
the wipe or change the
appearance of the interior
surface when used.
.Do not use scented or
gel-type hand sanitizers.
If hand sanitizer comes in
contact with interior
surfaces of the vehicle,
blot immediately and clean(Continued)

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
462 Vehicle Care
Caution (Continued)
with a soft cloth
dampened with a mild
soap and water solution.
Interior Glass
To clean, use a microfiber
cloth fabric dampened with
water. Wipe droplets left
behind with a clean dry cloth.
If necessary, use a commercial
glass cleaner after cleaning
with plain water.
Caution
To prevent scratching, never
use abrasive cleaners on
automotive glass. Abrasive
cleaners or aggressive
cleaning may damage the
rear window defogger.
Cleaning the windshield with
water during the first three to
six months of ownership will
reduce tendency to fog.
Speaker Covers
Vacuum around a speaker
cover gently, so that the
speaker will not be damaged.
Clean spots with water and
mild soap.
Coated Moldings
Coated moldings should be
cleaned.
.When lightly soiled, wipe
with a sponge or soft,
lint-free cloth dampened
with water.
.When heavily soiled, use
warm soapy water.
Vinyl/Rubber
If equipped with vinyl floor and
rubber floor mats, use a soft
cloth and/or brush dampened
with water to remove dust and
loose dirt. For more thorough
cleaning, use a mild soap and
water solution.
{Warning
Do not use cleaners that
contain silicone, wax-based
products, or cleaners that
increase gloss on vinyl/
rubber floor and mats.
These cleaners can
permanently change the
appearance and feel of the
vinyl/rubber and can make
the floor slippery. Your foot
could slip while operating
the vehicle, and you could
lose control, resulting in a
crash. You or others could
be injured.
Fabric/Carpet/Suede
Start by vacuuming the
surface using a soft brush
attachment. If a rotating
vacuum brush attachment is
being used, only use it on the
floor carpet. Before cleaning,
gently remove as much of the
soil as possible:

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Service and Maintenance 467
Service and
Maintenance
General Information
General Information . . . . . . 467
Maintenance Schedule
MaintenanceSchedule . . . . . . . . . . . . . . . . . . . 469
Multi-Point Vehicle
Inspection (MPVI)
Multi-Point VehicleInspection (MPVI) . . . . . . . . 472
Special Application
Services
Special ApplicationServices . . . . . . . . . . . . . . . . . . . . 473
Recommended Fluids,
Lubricants, and Parts
Recommended Fluids andLubricants . . . . . . . . . . . . . . . . . 474
Maintenance Replacement Parts . . . . . . 475
Maintenance Records
Maintenance Records . . . . 477
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
(Continued)

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Service and Maintenance 469
Maintenance
Schedule
Tire Rotation and
Required Services Every
12 000 km (7,500 mi)
Tires are rotated to achieve a
more uniform wear for all tires.
The first rotation is the most
important.
Anytime unusual wear is
noticed, rotate the tires as
soon as possible, check for
proper tire inflation pressure,
and check for damaged tires
or wheels. If the unusual wear
continues after the rotation,
check the wheel alignment.
See When It Is Time for New
Tires0431 and
Wheel Replacement 0436.
.Perform Multi-Point Vehicle
Inspection. See Multi-Point
Vehicle Inspection (MPVI)
0472.
.Lubricate body components.
See Exterior Care 0455.
Additional Required
Services —Normal
Service
Every 12 000 km (7,500 mi)
.Check engine oil level and oil
life percentage. If needed,
change engine oil and filter,
and reset oil life system. Or
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 oil
life system must be reset.
Your trained dealer
technician can perform this
work. If the engine oil life
system is reset accidentally,
service the vehicle within
5 000 km/3,000 mi since the
last service. Reset the oil life system when the oil is
changed. See Engine Oil Life
System
0381.
.When the REPLACE AT
NEXT OIL CHANGE
message displays, the engine
air filter should be replaced
at the next engine oil
change. When the REPLACE
ENGINE AIR FILTER SOON
message displays, the engine
air filter should be replaced
at the earliest convenience.
Reset the engine air filter life
system after the engine air
filter is replaced. See Engine
Air Filter Life System 0383.
Every 36 000 km (22,500 mi)
.Passenger compartment air
filter replacement (or every
24 months, whichever
occurs first). More frequent
replacement may be needed
if the vehicle is driven in
areas with heavy traffic,
poor air quality, areas with
high dust levels or are
sensitive to environmental
allergens. Filter replacement