maintenance CADILLAC CT4 2021 Owner's Guide

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
VEHICLE CARE 327
Warning (Continued)
careful. SeeJump Starting - North
America 0366 for tips on working
around a battery without
getting hurt.
Infrequent Usage: Remove the black,
negative (−) cable from the battery to
keep the battery from running down.
Extended Storage: Remove the black,
negative (−) cable from the battery or
use a battery trickle charger.
All-Wheel Drive
If the vehicle is equipped with
All-Wheel-Drive (AWD), this is an
additional system that needs
lubrication.
Transfer Case
Under normal driving conditions,
transfer case fluid does not require
maintenance unless there is a fluid
leak or unusual noise. If required,
have the transfer case serviced by
your dealer.
Park Brake and P (Park)
Mechanism Check
{Warning
When you are doing this check, the
vehicle could begin to move. You or
others could be injured and
property could be damaged. Make
sure there is room in front of the
vehicle in case it begins to roll. Be
ready to apply the regular brake at
once should the vehicle begin
to move.
Park on a fairly steep hill, with the
vehicle facing downhill. Keeping your
foot on the regular brake, set the
parking brake.
.To check the parking brake's
holding ability: With the engine
running and the transmission in
N (Neutral), slowly remove foot
pressure from the regular brake
pedal. Do this until the vehicle is
held by the parking brake only.
.To check the P (Park) mechanism's
holding ability: With the engine
running, shift to P (Park). Then
release the parking brake followed
by the regular brake.
Contact your dealer if service is
required.
Wiper Blade Replacement
Windshield wiper blades should be
inspected for wear and cracking. See
Maintenance Schedule 0380.
Replacement blades come in different
types and are removed in different
ways. For proper type and length, see
Maintenance Replacement Parts 0392.
Caution
Allowing the wiper arm to touch
the windshield when no wiper blade
is installed could damage the
windshield. Any damage that occurs
would not be covered by the vehicle
warranty. Do not allow the wiper
arm to touch the windshield.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
VEHICLE CARE 329
Caution
Do not apply tape or hang any
objects from gas struts. Also do not
push down or pull on gas struts.
This may cause damage to the
vehicle.
See Maintenance Schedule 0380.
Hood
Trunk
Liftgate
Headlamp Aiming
Front Headlamp Aiming
Headlamp aim has been preset and
should need no further adjustment.
If the vehicle is damaged in a crash,
the headlamp aim may be affected.
If adjustment to the headlamps is
necessary, see your dealer.
Bulb Replacement
For the proper type of replacement
bulbs, or any bulb changing procedure
not listed in this section, contact your
dealer.
Caution
Do not replace incandescent bulbs
with aftermarket LED replacement
bulbs. This can cause damage to
the vehicle electrical system.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
VEHICLE CARE 349
soon as possible, and inflate them to
the proper pressure. Driving on a
significantly under-inflated tire causes
the tire to overheat and can lead to
tire failure. Under-inflation also
reduces fuel efficiency and tire tread
life, and may affect the vehicle's
handling and stopping ability.
Please note that the TPMS is not a
substitute for proper tire maintenance,
and it is the driver's responsibility to
maintain correct tire pressure, even if
under-inflation has not reached the
level to trigger illumination of the
TPMS low tire pressure telltale.
Your vehicle has also been equipped
with a TPMS malfunction indicator to
indicate when the system is not
operating properly. The TPMS
malfunction indicator is combined
with the low tire pressure telltale.
When the system detects a
malfunction, the telltale will flash for
approximately one minute and then
remain continuously illuminated. This
sequence will continue upon
subsequent vehicle start-ups as long
as the malfunction exists.When the malfunction indicator is
illuminated, the system may not be
able to detect or signal low tire
pressure as intended. TPMS
malfunctions may occur for a variety
of reasons, including the installation
of replacement or alternate tires or
wheels on the vehicle that prevent the
TPMS from functioning properly.
Always check the TPMS malfunction
telltale after replacing one or more
tires or wheels on your vehicle to
ensure that the replacement or
alternate tires and wheels allow the
TPMS to continue to function
properly.
See
Tire Pressure Monitor Operation
0 349.
See Radio Frequency Statement 0409.
Tire Pressure Monitor
Operation
This vehicle may have a Tire Pressure
Monitor System (TPMS). The TPMS is
designed to warn the driver when a
low tire pressure condition exists. TPMS sensors are mounted onto each
tire and wheel assembly, excluding the
spare tire and wheel assembly. The
TPMS sensors monitor the air
pressure in the tires and transmit the
tire pressure readings to a receiver
located in the vehicle.
When a low tire pressure condition is
detected, the TPMS illuminates the
low tire pressure warning light located
on the instrument cluster. If the
warning light comes on, stop as soon
as possible and inflate the tires to the
recommended pressure shown on the
Tire and Loading Information label.
See
Vehicle Load Limits 0214.
A message to check the pressure in a
specific tire displays in the Driver
Information Center (DIC). The low tire
pressure warning light and the DIC
warning message come on at each
ignition cycle until the tires are
inflated to the correct inflation

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
350 VEHICLE CARE
pressure. Using the DIC, tire pressure
levels can be viewed. For additional
information and details about the DIC
operation and displays seeDriver
Information Center (DIC) (Base Level)
0 107 or
Driver Information Center (DIC)
(Uplevel) 0110.
The low tire pressure warning light
may come on in cool weather when
the vehicle is first started, and then
turn off as the vehicle is driven. This
could be an early indicator that the air
pressure is getting low and needs to
be inflated to the proper pressure.
A Tire and Loading Information label,
attached to your vehicle, shows the
size of the original equipment tires
and the correct inflation pressure for
the tires when they are cold. See
Vehicle Load Limits 0214, for an
example of the Tire and Loading
Information label and its location.
Also see Tire Pressure 0346.
The TPMS can warn about a low tire
pressure condition but it does not replace normal tire maintenance. See
Tire Inspection
0352, Tire Rotation
0 352 and
Tires 0339.
Caution
Tire sealant materials are not all
the same. A non-approved tire
sealant could damage the TPMS
sensors. TPMS sensor damage
caused by using an incorrect tire
sealant is not covered by the
vehicle warranty. Always use only
the GM approved tire sealant
available through your dealer or
included in the vehicle.
Factory-installed Tire Inflator Kits use
a GM-approved liquid tire sealant.
Using non-approved tire sealants
could damage the TPMS sensors. See
Tire Sealant and Compressor Kit 0360
for information regarding the inflator
kit materials and instructions.
TPMS Malfunction Light and
Message
The TPMS will not function properly if
one or more of the TPMS sensors are
missing or inoperable. When the
system detects a malfunction, the low
tire pressure warning light flashes for
about one minute and then stays on
for the remainder of the ignition cycle.
A DIC warning message also displays.
The malfunction light and DIC
warning message come on at each
ignition cycle until the problem is
corrected. Some of the conditions that
can cause these to come on are:
.One of the road tires has been
replaced with the spare tire. The
spare tire does not have a TPMS
sensor. The malfunction light and
DIC message should go off after the
road tire is replaced and the sensor
matching process is performed
successfully. See “TPMS Sensor
Matching Process” later in this
section.
.The TPMS sensor matching process
was not done or not completed
successfully after rotating the tires.
The malfunction light and the DIC

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
352 VEHICLE CARE
The TPMS will not activate the tire fill
alert properly under the following
conditions:
.There is interference from an
external device or transmitter.
.The air pressure from the inflation
device is not sufficient to inflate
the tire.
.There is a malfunction in the TPMS.
.There is a malfunction in the horn
or turn signal lamps.
.The identification code of the TPMS
sensor is not registered to the
system.
.The battery of the TPMS sensor
is low.
If the tire fill alert does not operate
due to TPMS interference, move the
vehicle about 1 m (3 ft) back or
forward and try again. If the tire fill
alert feature is not working, use a tire
pressure gauge.
TPMS Sensor Matching
Process —Auto Learn Function
Each TPMS sensor has a unique
identification code. The identification
code needs to be matched to a new tire/wheel position after rotating the
tires or replacing one or more of the
TPMS sensors. When a tire is
installed, the vehicle must be
stationary for about 20 minutes before
the system recalculates. The following
relearn process takes up to
10 minutes, driving at a minimum
speed of 20 km/h (12 mph). A dash (-)
or pressure value will display in the
DIC. See
Driver Information Center
(DIC) (Base Level) 0107 or
Driver Information Center (DIC)
(Uplevel) 0110. A warning message
displays in the DIC if a problem
occurs during the relearn process.
Tire Inspection
We recommend that the tires,
including the spare tire, if the
vehicle has one, be inspected for
signs of wear or damage at least
once a month.
Replace the tire if:
.The indicators at three or more
places around the tire can
be seen.
.There is cord or fabric showing
through the tire's rubber.
.The tread or sidewall is cracked,
cut, or snagged deep enough to
show cord or fabric.
.The tire has a bump, bulge,
or split.
.The tire has a puncture, cut,
or other damage that cannot be
repaired well because of the size
or location of the damage.
Tire Rotation
Tires should be rotated every
12 000 km (7,500 mi). See
Maintenance Schedule 0380.
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

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
VEHICLE CARE 353
rotation, check the wheel
alignment. SeeWhen It Is Time for
New Tires 0353 and
Wheel Replacement 0357.
Use this rotation pattern when
rotating the tires.
Adjust the front and rear tires to
the recommended inflation
pressure on the Tire and Loading
Information label after the tires
have been rotated. See Tire
Pressure 0346 and
Vehicle Load Limits 0214. Reset the Tire Pressure Monitor
System. See
Tire Pressure Monitor
Operation 0349.
Check that all wheel nuts are
properly tightened. See “Wheel
Nut Torque ”under Capacities and
Specifications 0396.
{Warning
Rust or dirt on a wheel, or on
the parts to which it is fastened,
can cause wheel nuts to become
loose over time. The wheel
could come off and cause a
crash. When changing a wheel,
remove any rust or dirt from
places where the wheel attaches
to the vehicle. In an emergency,
a cloth or paper towel can be
used; however, use a scraper or
wire brush later to remove all
rust or dirt. Lightly coat the inner diameter of
the wheel hub opening with wheel
bearing grease after a wheel
change or tire rotation to prevent
corrosion or rust build-up.
{Warning
Do not apply grease to the
wheel mounting surface, wheel
conical seats, or the wheel nuts
or bolts. Grease applied to these
areas could cause a wheel to
become loose or come off,
resulting in a crash.
When It Is Time for New
Tires
Factors, such as maintenance,
temperatures, driving speeds, vehicle
loading, and road conditions affect the
wear rate of the tires.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
354 VEHICLE CARE
Treadwear indicators are one way to
tell when it is time for new tires.
Treadwear indicators appear when the
tires have only 1.6 mm (1/16 in) or
less of tread remaining. SeeTire
Inspection 0352 and
Tire Rotation 0352 for additional
information.
The rubber in tires ages over time.
This also applies to the spare tire,
if the vehicle has one, even if it is
never used. Multiple factors including
temperatures, loading conditions, and
inflation pressure maintenance affect
how fast aging takes place. GM
recommends that tires, including the
spare if equipped, be replaced after six years, regardless of tread wear. To
identify the age of a tire, use the tire
manufacture date, which is the last
four digits of the DOT Tire
Identification Number (TIN) molded
into one side of the tire sidewall. The
last four digits of the TIN indicate the
tire manufactured date. The first two
digits represent the week and the last
two digits, the year. For example, the
third week of the year 2020 would
have a 4-digit DOT date of 0320. Week
01 is the first full week (Sunday
through Saturday) of each year.
Vehicle Storage
Tires age when stored normally
mounted on a parked vehicle. Park a
vehicle that will be stored for at least
a month in a cool, dry, clean area
away from direct sunlight to slow
aging. This area should be free of
grease, gasoline, or other substances
that can deteriorate rubber.
Parking for an extended period can
cause flat spots on the tires that may
result in vibrations while driving.
When storing a vehicle for at least a
month, remove the tires or raise the
vehicle to reduce the weight from the
tires.
Buying New Tires
GM has developed and matched
specific tires for the vehicle. The
original equipment tires installed
were designed to meet General
Motors Tire Performance Criteria
Specification (TPC Spec) system
rating. When replacement tires are
needed, GM strongly recommends
buying tires with the same TPC
Spec rating.
GM's exclusive TPC Spec system
considers over a dozen critical
specifications that impact the
overall performance of the vehicle,
including brake system
performance, ride and handling,
traction control, and tire pressure
monitoring performance. GM's
TPC Spec number is molded onto
the tire's sidewall near the tire
size. If the tires have an all-season
tread design, the TPC Spec

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
VEHICLE CARE 355
number will be followed by MS for
mud and snow. SeeTire Sidewall
Labeling 0342 for additional
information.
GM recommends replacing worn
tires in complete sets of four.
Uniform tread depth on all tires
will help to maintain the
performance of the vehicle.
Braking and handling performance
may be adversely affected if all the
tires are not replaced at the same
time. If proper rotation and
maintenance have been done, all
four tires should wear out at
about the same time. However,
if it is necessary to replace only
one axle set of worn tires, place
the new tires on the rear axle. See
Tire Rotation 0352.
{Warning
Tires could explode during
improper service. Attempting to
mount or dismount a tire could
cause injury or death. Only your
(Continued)
Warning (Continued)
dealer or authorized tire service
center should mount or
dismount the tires.
{Warning
Mixing tires of different sizes
(other than those originally
installed on the vehicle), brands,
tread patterns, or types may
cause loss of vehicle control,
resulting in a crash or other
vehicle damage. Use the correct
size, brand, and type of tire on
all wheels.
{Warning
Using bias-ply tires on the
vehicle may cause the wheel rim
flanges to develop cracks after
many miles of driving. A tire
and/or wheel could fail suddenly
(Continued)
Warning (Continued)
and cause a crash. Use only
radial-ply tires with the wheels
on the vehicle.
Winter tires with the same speed
rating as the original equipment
tires may not be available for H, V,
W, Y and ZR speed rated tires.
Never exceed the winter tires’
maximum speed capability when
using winter tires with a lower
speed rating.
If the vehicle tires must be
replaced with a tire that does not
have a TPC Spec number, make
sure they are the same size, load
range, speed rating, and
construction (radial) as the
original tires.
The Tire and Loading Information
label indicates the original
equipment tires on the vehicle.
See Vehicle Load Limits 0214.

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374 VEHICLE CARE
Caution
To avoid surface damage on wheels
and wheel trim, do not use strong
soaps, chemicals, abrasive polishes,
cleaners, or brushes. Use only GM
approved cleaners. Do not drive the
vehicle through an automatic car
wash that uses silicon carbide tire/
wheel cleaning brushes. Damage
could occur and the repairs would
not be covered by the vehicle
warranty.
Brake System
Visually inspect brake lines and hoses
for proper hook-up, binding, leaks,
cracks, chafing, etc. Inspect disc brake
pads for wear and rotors for surface
condition. Inspect drum brake linings/
shoes for wear or cracks. Inspect all
other brake parts.
Steering, Suspension, and
Chassis Components
Visually inspect steering, suspension,
and chassis components for damaged,
loose, or missing parts or signs of
wear at least once a year.Inspect power steering for proper
attachment, connections, binding,
leaks, cracks, chafing, etc.
Visually check constant velocity joint
boots and axle seals for leaks.
Body Component Lubrication
Lubricate all key lock cylinders, hood
hinges, liftgate hinges, and the steel
fuel door hinge, unless the
components are plastic. Applying
silicone grease on weatherstrips with a
clean cloth will make them last
longer, seal better, and not stick or
squeak.
Underbody Maintenance
At least twice a year, spring and fall,
use plain water to flush any corrosive
materials from the underbody. Take
care to thoroughly clean any areas
where mud and other debris can
collect.
Do not directly power wash the
transfer case and/or front/rear axle
output seals. High pressure water can
overcome the seals and contaminate
the fluid. Contaminated fluid will
decrease the life of the transfer case
and/or axles and should be replaced
Sheet Metal Damage
If the vehicle is damaged and requires
sheet metal repair or replacement,
make sure the body repair shop
applies anti-corrosion material to
parts repaired or replaced to restore
corrosion protection.
Original manufacturer replacement
parts will provide the corrosion
protection while maintaining the
vehicle warranty.
Finish Damage
Quickly repair minor chips and
scratches with touch-up materials
available from your dealer to avoid
corrosion. Larger areas of finish
damage can be corrected in your
dealer's body and paint shop.
Chemical Paint Spotting
Airborne pollutants can fall upon and
attack painted vehicle surfaces
causing blotchy, ring-shaped
discolorations, and small, irregular

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
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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