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Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
SERVICE AND MAINTENANCE 359
Maintenance Schedule
Owner Checks and Services
Check the engine oil level. SeeEngine
Oil 0277.
Once a Month
. Check the tire inflation pressures.
See Tire Pressure 0322.
. Inspect the tires for wear. See Tire
Inspection 0329.
. Check the windshield washer fluid
level. See Washer Fluid 0289.
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
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
0280.
Engine Air Filter Change
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 0281.
Air Conditioning Desiccant
(Replace Every Seven Years)
The air conditioning system requires
maintenance every seven years. This
service requires replacement of the
desiccant to help the longevity and
efficient operation of the air
conditioning system. This service can
be complex. See your dealer.
Tire Rotation and Required
Services Every 12 000 km
(7,500 mi)
Rotate the tires, if recommended for
the vehicle, and perform the following
services. See Tire Rotation0329.
. Check engine oil level and oil
life percentage. If needed,
change engine oil and filter,
and reset oil life system. See
Engine Oil 0277 and
Engine Oil Life System 0280.
. If equipped with the engine air
filter life system, check the air
filter life percentage. If necessary,
replace the engine air filter and
reset the engine air filter life
system. See Engine Air Filter Life
System 0281. If the vehicle is not
equipped with the engine air filter
life system, inspect the engine air
cleaner filter. See Engine Air
Cleaner/Filter 0282.
. Check engine coolant level. See
Cooling System 0284.
. Check windshield washer fluid
level. See Washer Fluid 0289.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
360 SERVICE AND MAINTENANCE
.Check tire inflation pressures. See
Tire Pressure 0322.
. Inspect tire wear. See Tire
Inspection 0329.
. Visually check for fluid leaks.
. Inspect brake system. See Exterior
Care 0349.
. Visually inspect steering,
suspension, and chassis
components for damage, including
cracks or tears in the rubber boots,
loose or missing parts, or signs of
wear at least once a year. See
Exterior Care 0349.
. Inspect power steering for proper
attachment, connections, binding,
leaks, cracks, chafing, etc. .
Visually inspect halfshafts and
driveshafts for excessive wear,
lubricant leaks, and/or damage
including: tube dents or cracks,
constant velocity joint or universal
joint looseness, cracked or missing
boots, loose or missing boot
clamps, center bearing excessive
looseness, loose or missing
fasteners, and axle seals leaks.
. Check restraint system
components. See Safety System
Check 064.
. Visually inspect fuel system for
damage or leaks.
. Visually inspect exhaust system
and nearby heat shields for loose
or damaged parts. .
Lubricate body components. See
Exterior Care 0349.
. Check starter switch. See Starter
Switch Check 0294.
. Check parking brake and
automatic transmission park
mechanism. See Park Brake and
P (Park) Mechanism Check 0294.
. Check accelerator pedal for
damage, high effort, or binding.
Replace if needed.
. Visually inspect gas strut for signs
of wear, cracks, or other damage.
Check the hold open ability of the
strut. If the hold open ability is
low, service the gas strut. See Gas
Strut(s) 0296.
. Inspect sunroof track and seal,
if equipped. See Sunroof041.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
SERVICE AND MAINTENANCE 361
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 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. Check engine air filter life percentage and
status. Change engine air filter, if needed.
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
Replace passenger compartment air filter. (2)@ @@@@@
Inspect evaporative control system. (3)@ @@
Replace spark plugs. Inspect spark plug wires and/or
boots. (4.2L Engine)@ @
Replace spark plugs. Inspect spark plug wires and/or
boots. (3.6L Engine)@
Change transfer case fluid. (4)@
Change rear axle fluid. (Except V-Series) (4)@
Change rear axle fluid. (V-Series Only) (4)@@@
Change front axle fluid 4WD. (4)@
Drain and fill engine cooling system. (5)@
Visually inspect accessory drive belts. (6)@
Replace brake fluid. (7)
Replace windshield wiper blades. (8)
@ @ @ @ @ @ @ @ @ @
Replace hood and/or body lift support gas struts. (9)@ @
Replace air conditioning desiccant. (10)

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
362 SERVICE AND MAINTENANCE
Footnotes—Maintenance Schedule
Additional Required Services -
Normal
(1) Vehicles with different size front
and rear tires do not have tire
rotation. See Tire Rotation0329.
(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)
Visually check all fuel and vapor
lines and hoses for proper attachment,
connection, routing, and condition.
(4) 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.
(5) Or every five years, whichever
comes first. See Cooling System0284. (6)
Or every 10 years, whichever
comes first. Inspect for fraying,
excessive cracking, or damage; replace,
if needed.
(7) Replace brake fluid every five
years. See Brake Fluid 0291.
(8) Or every 12 months, whichever
comes first. See Wiper Blade
Replacement 0295.
(9) Or every 10 years, whichever
comes first. See Gas Strut(s)0296.
(10) Replace air conditioning
desiccant every seven years.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
SERVICE AND MAINTENANCE 363
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. Check engine air filter life percentage and
status. Change engine air filter, if needed.
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
Replace passenger compartment air filter. (2)@ @@@@@
Inspect evaporative control system. (3)@ @@
Replace spark plugs. Inspect spark plug wires and/or
boots. (4.2L Engine)@ @
Replace spark plugs. Inspect spark plug wires and/or
boots. (3.6L Engine)@
Change automatic transmission fluid and filter.@@@
Change transfer case fluid. (4)@@@
Change rear axle fluid. (4)@@@
Change front axle fluid 4WD. (4)@@@
Drain and fill engine cooling system. (5)@
Visually inspect accessory drive belts. (6)@
Replace brake fluid. (7)
Replace windshield wiper blades. (8)
@ @ @ @ @ @ @ @ @ @
Replace hood and/or body lift support gas struts. (9)@ @
Replace air conditioning desiccant. (10)

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
364 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 Rotation0329.
(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) Visually check all fuel and vapor
lines and hoses for proper attachment,
connection, routing, and condition.
(4) 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.
(5)
Or every five years, whichever
comes first. See Cooling System0284.
(6) Or every 10 years, whichever
comes first. Inspect for fraying,
excessive cracking, or damage; replace,
if needed.
(7) Replace brake fluid every five
years. See Brake Fluid 0291.
(8) Or every 12 months, whichever
comes first. See Wiper Blade
Replacement 0295.
(9) Or every 10 years, whichever
comes first. See Gas Strut(s)0296.
(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 Care
0 349.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
SERVICE AND MAINTENANCE 365
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.
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 0368 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.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
366 SERVICE AND MAINTENANCE
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. 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 0353 and
Exterior Care 0349.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
SERVICE AND MAINTENANCE 367
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 CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
368 SERVICE AND MAINTENANCE
Recommended Fluids, Lubricants, and Parts
Recommended Fluids and Lubricants
UsageFluid/Lubricant
Automatic Transmission DEXRON-ULV Automatic Transmission Fluid (GM Part No. 19352619, in Canada 19352620).
Engine Coolant 50/50 mixture of clean drinkable water and use only DEX-COOL Coolant.
Engine Oil (3.6L V6 Engine) Engine oil meeting the dexos1 specification of the proper SAE viscosity grade. ACDelco dexos1 full synthetic is recommended. See Engine Oil0277.
Engine Oil (4.2L V8 Twin Turbo Engine) Engine oil meeting the dexos2 specification of the proper SAE viscosity grade. ACDelco dexos2 is recommended. SeeEngine Oil0277.
Hood Latch Assembly, Pivots, Spring Anchor, and Release Pawl Lubriplate Lubricant Aerosol (GM Part No. 89021668, in Canada 89021674) or
lubricant meeting requirements of NLGI #2, Category LB or GC-LB.
Hydraulic Brake System DOT 3 Hydraulic Brake Fluid (GM Part No. 19353126, in Canada 19353127).
Key Lock Cylinders, Hood and Door Hinges Multi-Purpose Lubricant, Superlube (GM Part No. 12346241, in
Canada 10953474).
Rear Axle (Except V-Series)/Front Axle SAE 75W-90 Synthetic Axle Lubricant (GM Part No. 88863089, in Canada 88863090).
Rear Axle (V-Series) SAE 75W-90 Synthetic Axle Lubricant (GM Part No. 88862624, in
Canada 88862625).
Transfer Case (All-Wheel Drive) Transfer Case Fluid (GM Part No. 19331044, in Canada 19331045).