fuel CADILLAC CT6 2020 Service Manual

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
350 VEHICLE CARE
soon as possible. If necessary, use
non-abrasive cleaners that are marked
safe for painted surfaces to remove
foreign matter.
Occasional hand waxing or mild
polishing should be done to remove
residue from the paint finish. See your
dealer for approved cleaning products.
Do not apply waxes or polishes to
uncoated plastic, vinyl, rubber, decals,
simulated wood, or flat paint as
damage can occur.
Caution
Machine compounding or
aggressive polishing on a basecoat/
clearcoat paint finish may damage
it. Use only non-abrasive waxes and
polishes that are made for a
basecoat/clearcoat paint finish on
the vehicle.
To keep the paint finish looking new,
keep the vehicle garaged or covered
whenever possible. Protecting Exterior Bright Metal
Moldings
Caution
Failure to clean and protect the
bright metal moldings can result in
a hazy white finish or pitting. This
damage would not be covered by
the vehicle warranty.
The bright metal moldings on the
vehicle are aluminum, chrome,
or stainless steel. To prevent damage,
always follow these cleaning
instructions:
. Be sure the molding is cool to the
touch before applying any cleaning
solution.
. Use only approved cleaning
solutions for aluminum, chrome,
or stainless steel. Some cleaners
are highly acidic or contain
alkaline substances and can
damage the moldings.
. Always dilute a concentrated
cleaner according to the
manufacturer’s instructions. .
Do not use cleaners that are not
intended for automotive use.
. Use a nonabrasive wax on the
vehicle after washing to protect
and extend the molding finish.Cleaning Exterior Lamps/Lenses,
Emblems, Decals, and Stripes
Use only lukewarm or cold water, a
soft cloth, and a car washing soap to
clean exterior lamps, lenses, emblems,
decals, and stripes. Follow instructions
under "Washing the Vehicle"
previously in this section.
Lamp covers are made of plastic, and
some have a UV protective coating. Do
not clean or wipe them when dry.
Do not use any of the following on
lamp covers:
.Abrasive or caustic agents.
. Washer fluids and other cleaning
agents in higher concentrations
than suggested by the
manufacturer.
. Solvents, alcohols, fuels, or other
harsh cleaners.
. Ice scrapers or other hard items.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
VEHICLE CARE 351
.Aftermarket appearance caps or
covers while the lamps are
illuminated, due to excessive heat
generated.
Caution
Failure to clean lamps properly can
cause damage to the lamp cover
that would not be covered by the
vehicle warranty.
Caution
Using wax on low gloss black finish
stripes can increase the gloss level
and create a non-uniform finish.
Clean low gloss stripes with soap
and water only.
Air Intakes
Clear debris from the air intakes
between the hood and windshield
when washing the vehicle.
Shutter System
The vehicle may have a shutter
system designed to help increase fuel
economy. Keep the shutter system
clean for proper operation.
Windshield and Wiper Blades
Clean the outside of the windshield
with glass cleaner.
Clean rubber blades using a lint-free
cloth or paper towel soaked with
windshield washer fluid or a mild
detergent. Wash the windshield
thoroughly when cleaning the blades. Bugs, road grime, sap, and a buildup
of vehicle wash/wax treatments may
cause wiper streaking.
Replace the wiper blades if they are
worn or damaged. Damage can be
caused by extreme dusty conditions,
sand, salt, heat, sun, snow, and ice.
Weatherstrips
Apply weatherstrip lubricant on
weatherstrips to make them last
longer, seal better, and not stick or
squeak. Lubricate weatherstrips at
least once a year. Hot, dry climates
may require more frequent
application. Black marks from rubber
material on painted surfaces can be
removed by rubbing with a clean
cloth. See
Recommended Fluids and
Lubricants 0368.
Tires
Use a stiff brush with tire cleaner to
clean the tires.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
352 VEHICLE CARE
Caution
Using petroleum-based tire dressing
products on the vehicle may
damage the paint finish and/or
tires. When applying a tire dressing,
always wipe off any overspray from
all painted surfaces on the vehicle.
Wheels and Wheel Trim
Use a soft, clean cloth with mild soap
and water to clean the wheels. After
rinsing thoroughly with clean water,
dry with a soft, clean towel. A wax
may then be applied.
Caution
Chrome wheels and chrome wheel
trim may be damaged if the vehicle
is not washed after driving on roads
that have been sprayed with
magnesium chloride or calcium
chloride. These are used on roads
for conditions such as dust and ice.
Always wash the chrome with soap
and water after exposure.
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 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 hinges, 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

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
358 SERVICE AND MAINTENANCE
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
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 Limits 0179.
. Are driven on reasonable road
surfaces within legal driving limits. .
Use the recommended fuel.
See Recommended Fuel (3.6L
V6 Engine) 0258 or
Recommended Fuel (4.2L Twin
Turbo V8 Engine) 0259.
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.
. Frequently towing a trailer.
. 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 0272.

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
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
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
374 TECHNICAL DATA
ApplicationCapacities
Metric English
Front Axle 0.4 L 0.42 qt
Rear Axle 0.5 L 0.53 qt
Rear Axle 4.2L V8 Twin Turbo (LTA) Engine or V-Series 1.1 L 1.16 qt
Fuel Tank 72.7 L 19.2 gal
Transfer Case –AWD 0.8 L 0.85 qt
Wheel Nut Torque 150 Y110 lb ft
All capacities are approximate. When adding, be sure to fill to the approximate level, as recommended in this manual.
Recheck fluid level after filling.
*Engine cooling system capacity values are based on the entire cooling system and its components.
Engine Specifications
Engine VIN CodeTransmission Spark Plug Gap
3.6L V6 Engine (LGX) SAutomatic0.80–0.90 mm (0.031–0.035 in)
4.2L V8 Engine (LTA) JAutomatic 0.74–0.75 mm (0.029–0.030 in)
Spark plug gaps are preset by the manufacturer. Re-gapping the spark plug is not recommended and can damage the
spark plug.