2021 CADILLAC CT4 Owner's Manual

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
384 SERVICE AND MAINTENANCE
Maintenance Schedule
Additional Required Services -
Normal12 000 km/7,500 mi
24 000 km/15,000 mi
36 000 km/22,500 mi
48 000 km/30,000 mi
60 000 km/37,500 mi
72 000 km/45,000 mi
84 000 km/52,500 mi
96 000 km/60,000 mi
108 000 km/67,500 mi
120 000 km/75,000 mi
132 000 km/82,500 mi
144 000 km/90,000 mi
156 000 km/97,500 mi
168 000 km/105,000 mi
180 000 km/112,500 mi
192 000 km/120,000 mi
204 000 km/127,500 mi
216 000 km/135,000 mi
228 000 km/142,500 mi
240 000 k m/150,000 mi
Change rear axle fluid, without limited slip
differential. (5)@
Change front axle fluid, if equipped with AWD. (5)@
Drain and fill engine cooling system. (6)@
Visually inspect accessory drive belts. (7)@
Replace brake fluid. (8)
Replace windshield wiper blades. (9)
@ @ @ @ @ @ @ @ @ @
Replace hood and/or body lift support gas
struts. (10)@ @
Replace air conditioning desiccant. (11)

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
SERVICE AND MAINTENANCE 385
Footnotes—Maintenance Schedule
Additional Required Services -
Normal
(1) Vehicles with different size front
and rear tires do not have tire
rotation. See Tire Rotation0352.
(2) Or every two years, whichever
comes first. More frequent passenger
compartment air filter replacement
may be needed if driving in areas with
heavy traffic, poor air quality, high
dust levels, or environmental
allergens. Passenger compartment air
filter replacement may also be needed
if there is reduced airf low, window
fogging, or odors. Your GM dealer can
help determine when to replace the
filter.
(3) Or every four years, whichever
comes first. If driving in dusty
conditions, inspect the filter at each
oil change or more often as needed.
See Engine Air Cleaner/Filter 0316.
(4) Visually check all fuel and vapor
lines and hoses for proper attachment,
connection, routing, and condition. (5)
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 transfer case fluid. Contaminated
fluid will decrease the life of the
transfer case and/or axles and should
be replaced.
(6) Or every five years, whichever
comes first. See Cooling System0317.
(7) Or every 10 years, whichever
comes first. Inspect for fraying,
excessive cracking, or damage; replace,
if needed.
(8) Replace brake fluid every five
years. See Brake Fluid 0325.
(9) Or every 12 months, whichever
comes first. See Wiper Blade
Replacement 0327.
(10) Or every 10 years, whichever
comes first. See Gas Strut(s)0328.
(11) Replace air conditioning
desiccant every seven years.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
386 SERVICE AND MAINTENANCE
Maintenance Schedule
Additional Required Services -
Severe12 000 km/7,500 mi
24 000 km/15,000 mi
36 000 km/22,500 mi
48 000 km/30,000 mi
60 000 km/37,500 mi
72 000 km/45,000 mi
84 000 km/52,500 mi
96 000 km/60,000 mi
108 000 km/67,500 mi
120 000 km/75,000 mi
132 000 km/82,500 mi
144 000 km/90,000 mi
156 000 km/97,500 mi
168 000 km/105,000 mi
180 000 km/112,500 mi
192 000 km/120,000 mi
204 000 km/127,500 mi
216 000 km/135,000 mi
228 000 km/142,500 mi
240 000 km/150,000 mi
Rotate tires, if recommended for the vehicle, and
perform Required Services. (1) Check engine oil level
and oil life percentage. Change engine oil and filter,
if needed.
If equipped, check engine air filter life percentage
and status. Change engine air filter, if needed.
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
Replace passenger compartment air filter. (2)@ @@@@@
If the vehicle is not equipped with the engine air
filter life system, replace engine air cleaner filter. (3)@ @@
Inspect evaporative control system. (4)@@@
Replace spark plugs. Inspect spark plug wires and/or
boots.@ @
Change automatic transmission fluid and filter.@@@
Change transfer case fluid, if equipped with
AWD. (5)@@@
Change rear axle fluid, if equipped with limited slip
differential. (5)@@@

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
SERVICE AND MAINTENANCE 387
Maintenance Schedule
Additional Required Services -
Severe12 000 km/7,500 mi
24 000 km/15,000 mi
36 000 km/22,500 mi
48 000 km/30,000 mi
60 000 km/37,500 mi
72 000 km/45,000 mi
84 000 km/52,500 mi
96 000 km/60,000 mi
108 000 km/67,500 mi
120 000 km/75,000 mi
132 000 km/82,500 mi
144 000 km/90,000 mi
156 000 km/97,500 mi
168 000 km/105,000 mi
180 000 km/112,500 mi
192 000 km/120,000 mi
204 000 km/127,500 mi
216 000 km/135,000 mi
228 000 km/142,500 mi
240 000 km/150,000 mi
Change rear axle fluid, without limited slip
differential. (5)@ @
Change front axle fluid, if equipped with AWD. (5)@@@
Drain and fill engine cooling system. (6)@
Visually inspect accessory drive belts. (7)@
Replace brake fluid. (8)
Replace windshield wiper blades. (9)
@ @ @ @ @ @ @ @ @ @
Replace hood and/or body lift support gas
struts. (10)@ @
Replace air conditioning desiccant. (11)

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
388 SERVICE AND MAINTENANCE
Footnotes—Maintenance Schedule
Additional Required Services -
Severe
(1) Vehicles with different size front
and rear tires do not have tire
rotation. See Tire Rotation0352.
(2) Or every two years, whichever
comes first. More frequent passenger
compartment air filter replacement
may be needed if driving in areas with
heavy traffic, poor air quality, high
dust levels, or environmental
allergens. Passenger compartment air
filter replacement may also be needed
if there is reduced airf low, window
fogging, or odors. Your GM dealer can
help determine when to replace the
filter.
(3) Or every four years, whichever
comes first. If driving in dusty
conditions, inspect the filter at each
oil change or more often as needed.
See Engine Air Cleaner/Filter 0316.
(4) Visually check all fuel and vapor
lines and hoses for proper attachment,
connection, routing, and condition. (5)
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 transfer case fluid. Contaminated
fluid will decrease the life of the
transfer case and/or axles and should
be replaced.
(6) Or every five years, whichever
comes first. See Cooling System0317.
(7) Or every 10 years, whichever
comes first. Inspect for fraying,
excessive cracking, or damage; replace,
if needed.
(8) Replace brake fluid every five
years. See Brake Fluid 0325.
(9) Or every 10 years, whichever
comes first. See Gas Strut(s)0328.
(10) Replace air conditioning
desiccant every seven years.Special Application
Services
.Severe Commercial Use Vehicles
Only: Lubricate chassis components
every oil change.
.Have underbody flushing service
performed. See "Underbody
Maintenance" in Exterior Care0370.
Additional Maintenance
and Care
Your vehicle is an important
investment and caring for it properly
may help to avoid future costly
repairs. To maintain vehicle
performance, additional maintenance
services may be required.
It is recommended that your dealer
perform these services —their trained
dealer technicians know your vehicle
best. Your dealer can also perform a
thorough assessment with a
multi-point inspection to recommend
when your vehicle may need
attention.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
SERVICE AND MAINTENANCE 389
The following list is intended to
explain the services and conditions to
look for that may indicate services are
required.
Battery
The 12-volt battery supplies power to
start the engine and operate any
additional electrical accessories.
.To avoid break-down or failure to
start the vehicle, maintain a battery
with full cranking power.
.Trained dealer technicians have the
diagnostic equipment to test the
battery and ensure that the
connections and cables are
corrosion-free.
Belts
.Belts may need replacing if they
squeak or show signs of cracking or
splitting.
.Trained dealer technicians have
access to tools and equipment to
inspect the belts and recommend
adjustment or replacement when
necessary. Brakes
Brakes stop the vehicle and are crucial
to safe driving.
.Signs of brake wear may include
chirping, grinding, or squealing
noises, or difficulty stopping.
.Trained dealer technicians have
access to tools and equipment to
inspect the brakes and recommend
quality parts engineered for the
vehicle.
Fluids
Proper fluid levels and approved fluids
protect the vehicle’s systems and
components. See Recommended Fluids
and Lubricants 0391 for GM approved
fluids.
.Engine oil and windshield washer
fluid levels should be checked at
every fuel fill.
.Instrument cluster lights may come
on to indicate that fluids may be
low and need to be filled. Hoses
Hoses transport fluids and should be
regularly inspected to ensure that
there are no cracks or leaks. With a
multi-point inspection, your dealer
can inspect the hoses and advise if
replacement is needed.
Lamps
Properly working headlamps,
taillamps, and brake lamps are
important to see and be seen on
the road.
.Signs that the headlamps need
attention include dimming, failure
to light, cracking, or damage. The
brake lamps need to be checked
periodically to ensure that they light
when braking.
.With a multi-point inspection, your
dealer can check the lamps and
note any concerns.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
390 SERVICE AND MAINTENANCE
Shocks and Struts
Shocks and struts help aid in control
for a smoother ride.
.Signs of wear may include steering
wheel vibration, bounce/sway while
braking, longer stopping distance,
or uneven tire wear.
.As part of the multi-point
inspection, trained dealer
technicians can visually inspect the
shocks and struts for signs of
leaking, blown seals, or damage, and
can advise when service is needed.
Tires
Tires need to be properly inflated,
rotated, and balanced. Maintaining
the tires can save money and fuel, and
can reduce the risk of tire failure.
.Signs that the tires need to be
replaced include three or more
visible treadwear indicators; cord or
fabric showing through the rubber;
cracks or cuts in the tread or
sidewall; or a bulge or split in
the tire.
.Trained dealer technicians can
inspect and recommend the right
tires. Your dealer can also provide
tire/wheel balancing services to
ensure smooth vehicle operation at
all speeds. Your dealer sells and
services name brand tires.
Vehicle Care
To help keep the vehicle looking like
new, vehicle care products are
available from your dealer. For
information on how to clean and
protect the vehicle’s interior and
exterior, see Interior Care 0375 and
Exterior Care 0370.
Wheel Alignment
Wheel alignment is critical for
ensuring that the tires deliver optimal
wear and performance.
.Signs that the alignment may need
to be adjusted include pulling,
improper vehicle handling,
or unusual tire wear.
.Your dealer has the required
equipment to ensure proper wheel
alignment. Windshield
For safety, appearance, and the best
viewing, keep the windshield clean
and clear.
.Signs of damage include scratches,
cracks, and chips.
.Trained dealer technicians can
inspect the windshield and
recommend proper replacement if
needed.
Wiper Blades
Wiper blades need to be cleaned and
kept in good condition to provide a
clear view.
.Signs of wear include streaking,
skipping across the windshield, and
worn or split rubber.
.Trained dealer technicians can
check the wiper blades and replace
them when needed.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
SERVICE AND MAINTENANCE 391
Recommended Fluids, Lubricants, and Parts
Recommended Fluids and Lubricants
Fluids and lubricants identified below by name or specification, including fluids or lubricants not listed here, can be
obtained from your dealer.Usage Fluid/Lubricant
Automatic Transmission (8-Speed Transmission) DEXRON-HP Automatic Transmission Fluid.
Automatic Transmission (10-Speed Transmission) DEXRON ULV Automatic Transmission Fluid.
Chassis Lubrication Chassis lubricant meeting requirements of NLGI #2, Category LB or GC-LB. Engine Coolant 50/50 mixture of clean, drinkable water and use only DEX-COOL Coolant. See Cooling System0317.
Engine Oil Engine oil meeting the dexos1 specification of the proper SAE viscosity grade. ACDelco dexos1 full synthetic is recommended. See Engine Oil0312.
Hood Latch Assembly, Secondary Latch,
Pivots, Spring Anchor, and Release Pawl Lubriplate Lubricant Aerosol or lubricant meeting requirements of NLGI #2,
Category LB or GC-LB.
Hydraulic Brake System DOT 4 Hydraulic Brake Fluid.
Key Lock Cylinders, Hood and Door Hinges Multi-Purpose Lubricant, Superlube. See your dealer.
Rear Axle/Front Axle (All-Wheel Drive) See your dealer. Windshield Washer Automotive windshield washer fluid that meets regional freeze protection requirements.