service CADILLAC CT6 2016 Repair Manual

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/6/15
272 Vehicle Care Viscosity Grade
Use SAE 5W-30 viscosity grade
engine oil.
Cold Temperature Operation: In an
area of extreme cold, where the
temperature falls below − 29 °C
( − 20 °F), an SAE 0W-30 oil may be
used. An oil of this viscosity grade
will provide easier cold starting for
the engine at extremely low
temperatures. When selecting an oil
of the appropriate viscosity grade, it
is recommended to select an oil of
the correct specification. See
“ Specification ” earlier in this section.
Engine Oil Additives/Engine
Oil Flushes Do not add anything to the oil. The
recommended oils meeting the
dexos1 specification are all that is
needed for good performance and
engine protection.
Engine oil system flushes are not
recommended and could cause
engine damage not covered by the
vehicle warranty. What to Do with Used Oil Used engine oil contains certain
elements that can be unhealthy for
your skin and could even cause
cancer. Do not let used oil stay on
your skin for very long. Clean your
skin and nails with soap and water,
or a good hand cleaner. Wash or
properly dispose of clothing or rags
containing used engine oil. See the
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 at which 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. See
Engine Oil Messages 0 149 .
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.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/6/15
Vehicle Care 277
Engine Coolant The cooling system in the vehicle is
filled with DEX-COOL ®
engine
coolant. This coolant needs to be
checked and replaced at
appropriate intervals. See
Maintenance Schedule 0 344 .
The following explains the cooling
system and how to check and add
coolant when it is low. If there is a
problem with engine overheating,
see Engine Overheating 0 280 .
What to Use
{ WarningAdding only plain water or some
other liquid to the cooling system
can be dangerous. Plain water
and other liquids, can boil before
the proper coolant mixture will.
The coolant warning system is set
for the proper coolant mixture.
With plain water or the wrong
mixture, the engine could get too
hot but you would not get the
(Continued) Warning (Continued) overheat warning. The engine
could catch fire and you or others
could be burned. Use a 50/
50 mixture of clean, drinkable
water and DEX-COOL coolant.
Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
coolant. If using this mixture,
nothing else needs to be added.
This mixture:
.
Gives freezing protection down
to − 37 °C ( − 34 °F), outside
temperature.
.
Gives boiling protection up to
129 °C (265 °F), engine
temperature.
.
Protects against rust and
corrosion.
.
Will not damage aluminum parts.
.
Helps keep the proper engine
temperature. CautionIf improper coolant mixture,
inhibitors, or additives are used in
the vehicle cooling system, the
engine could overheat and be
damaged. Too much water in the
mixture can freeze and crack
engine cooling parts. The repairs
would not be covered by the
vehicle warranty. Use only the
proper mixture of engine coolant
for the cooling system. See
Recommended Fluids and
Lubricants 0 353 .
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.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/6/15
280 Vehicle Care 5. Replace the pressure cap
tightly.
6. Verify coolant level after the
engine is shut off and the
coolant is cold. If necessary,
repeat coolant fill procedure
Steps 1 – 6.
If the coolant still is not at the
proper level when the system
cools down again, see your
dealer.
CautionIf the pressure cap is not tightly
installed, coolant loss and
possible engine damage may
occur. Be sure the cap is properly
and tightly secured.
Engine Overheating The vehicle has several indicators
to warn of the engine overheating.
There is an engine coolant
temperature gauge and an engine
coolant temperature warning light on the instrument cluster. See Engine
Coolant Temperature Gauge 0 128
and Engine Coolant Temperature
Warning Light 0 137 . The vehicle
may also display a message on the
Driver Information Center (DIC).
See Engine Cooling System
Messages 0 149 .
If the decision is made not to lift the
hood when this warning appears,
get service help right away. See
Roadside Service 0 364 .
If the decision is made to lift the
hood, make sure the vehicle is
parked on a level surface. Then
check to see if the engine cooling
fan is running. If the engine is
overheating, the fan should be
running. If it is not, do not continue
to run the engine. Have the vehicle
serviced.
Caution
Running the engine without
coolant may cause damage or a
fire. Vehicle damage would not be
covered by the vehicle warranty. If Steam Is Coming from the
Engine Compartment
{ WarningSteam from an overheated engine
can burn you badly, even if you
just open the hood. Stay away
from the engine if you see or hear
steam coming from it. Just turn it
off and get everyone away from
the vehicle until it cools down.
Wait until there is no sign of
steam or coolant before you open
the hood.
If you keep driving when the
engine is overheated, the liquids
in it can catch fire. You or others
could be badly burned. Stop the
engine if it overheats, and get out
of the vehicle until the engine
is cool.
If No Steam Is Coming from
the Engine Compartment
If an engine overheat warning is
displayed but no steam can be seen
or heard, the problem may not be

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/6/15
282 Vehicle Care Caution (Continued).
Do not mix water with
ready-to-use washer fluid.
Water can cause the
solution to freeze and
damage the washer fluid
tank and other parts of the
washer system.
.
When using concentrated
washer fluid, follow the
manufacturer instructions for
adding water.
.
Fill the washer fluid tank
only three-quarters full when
it is very cold. This allows
for fluid expansion if
freezing occurs, which could
damage the tank if it is
completely full.
Brakes Disc brake pads have built-in wear
indicators that make a high-pitched
warning sound when the brake pads
are worn and new pads are needed.
The sound can come and go or can be heard all the time when the
vehicle is moving, except when
applying the brake pedal firmly.
{ WarningThe brake wear warning sound
means that soon the brakes will
not work well. That could lead to
a crash. When the brake wear
warning sound is heard, have the
vehicle serviced.
CautionContinuing to drive with worn-out
brake pads could result in costly
brake repair.
Some driving conditions or climates
can cause a brake squeal when the
brakes are first applied or lightly
applied. This does not mean
something is wrong with the brakes.
Properly torqued wheel nuts are
necessary to help prevent brake
pulsation. When tires are rotated,
inspect brake pads for wear and evenly tighten wheel nuts in the
proper sequence to torque
specifications. See Capacities and
Specifications 0 358 .
Brake pads should be replaced as
complete sets.
Brake Pedal Travel See your dealer if the brake pedal
does not return to normal height,
or if there is a rapid increase in
pedal travel. This could be a sign
that brake service may be required.
Replacing Brake System Parts Always replace brake system parts
with new, approved replacement
parts. If this is not done, the brakes
may not work properly. The braking
performance expected can change
in many other ways if the wrong
replacement brake parts are
installed or if parts are improperly
installed.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/6/15
Vehicle Care 285Transfer Case When to Check Lubricant
It is not necessary to regularly
check the transfer case fluid unless
a leak is suspected or an unusual
noise is heard. A fluid loss could
indicate a problem. Have it
inspected and repaired.
How to Check Lubricant
1. Fill Plug
2. Drain Plug
To get an accurate reading, the
vehicle should be on a level
surface. If the level is below the bottom of
the fill plug hole on the transfer
case, some lubricant will need to be
added. Add enough lubricant to
raise the level to the bottom of the
fill plug hole. Use care not to
overtighten the fill plug.
What to Use
To determine what kind of lubricant
to use, see Recommended Fluids
and Lubricants 0 353 .
Starter Switch Check
{ WarningWhen you are doing this
inspection, the vehicle could
move suddenly. If the vehicle
moves, you or others could be
injured.
1. Before starting this check, be
sure there is enough room
around the vehicle.
2. Firmly apply both the parking
brake and the regular brake.
Do not use the accelerator pedal, and be ready to turn off
the engine immediately if it
starts.
3. Try to start the engine in each
gear. The vehicle should start
only in P (Park) or N (Neutral).
If the vehicle starts in any other
position, contact your dealer for
service.
Automatic Transmission
Shift Lock Control
Function Check
{ WarningWhen you are doing this
inspection, the vehicle could
move suddenly. If the vehicle
moves, you or others could be
injured.
1. Before starting this check, be
sure there is enough room
around the vehicle. It should be
parked on a level surface.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/6/15
286 Vehicle Care 2. Firmly apply the parking brake.
See Electric Parking
Brake 0 214 .
Be ready to apply the regular
brake immediately if the vehicle
begins to move.
3. With the engine off, turn the
ignition on, but do not start the
engine. Without applying the
regular brake, try to move the
shift lever out of P (Park) with
normal effort. If the shift lever
moves out of P (Park), contact
your dealer for service.
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
(Continued) Warning (Continued) 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 or cracking.
For the proper type and size, see
Maintenance Replacement
Parts 0 354 .
To replace the wiper blade
assembly:
1. Pull the windshield wiper
assembly away from the
windshield.
2. Lift up on the latch in the
middle of the wiper blade
where the wiper arm attaches.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/6/15
Vehicle Care 299
Wheels and Tires Tires Every new GM vehicle has
high-quality tires made by a
leading tire manufacturer. See
the warranty manual for
information regarding the tire
warranty and where to get
service. For additional
information refer to the tire
manufacturer.
{ Warning.
Poorly maintained and
improperly used tires are
dangerous..
Overloading the tires can
cause overheating as a
result of too much
flexing. There could be a
blowout and a serious
crash. See Vehicle Load
Limits 0 198 .
(Continued) Warning (Continued) .
Underinflated tires pose
the same danger as
overloaded tires. The
resulting crash could
cause serious injury.
Check all tires frequently
to maintain the
recommended pressure.
Tire pressure should be
checked when the tires
are cold. .
Overinflated tires are
more likely to be cut,
punctured, or broken by
a sudden impact — such
as when hitting a pothole.
Keep tires at the
recommended pressure.
.
Worn or old tires can
cause a crash. If the
tread is badly worn,
replace them.
(Continued) Warning (Continued) .
Replace any tires that
have been damaged by
impacts with potholes,
curbs, etc. .
Improperly repaired tires
can cause a crash. Only
the dealer or an
authorized tire service
center should repair,
replace, dismount, and
mount the tires. .
Do not spin the tires in
excess of 56 km/h
(35 mph) on slippery
surfaces such as snow,
mud, ice, etc. Excessive
spinning may cause the
tires to explode.
See Tire Pressure for
High-Speed Operation 0 308 for
inflation pressure adjustment for
high-speed driving.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/6/15
Vehicle Care 301
Summer Tires This vehicle may come with high
performance summer tires. These
tires have a special tread and
compound that are optimized for
maximum dry and wet road
performance. This special tread and
compound will have decreased
performance in cold climates, and
on ice and snow. It is recommended
that winter tires be installed on the
vehicle if frequent driving at
temperatures below approximately
5 °C (40 °F) or on ice or snow
covered roads is expected. See
Winter Tires 0 300 .
Caution
High performance summer tires
have rubber compounds that lose
flexibility and may develop
surface cracks in the tread area
at temperatures below − 7 °C (20 °
F). Always store high
performance summer tires
indoors and at temperatures
above − 7 °C (20 °F) when not in
(Continued) Caution (Continued) use. If the tires have been
subjected to − 7 °C (20 °F) or less,
let them warm up in a heated
space to at least 5 °C (40 °F) for
24 hours or more before being
installed or driving a vehicle on
which they are installed. Do not
apply heat or blow heated air
directly on the tires. Always
inspect tires before use. See Tire
Inspection 0 312 .
Tire Sidewall Labeling Useful information about a tire is
molded into its sidewall. The
examples show a typical
passenger vehicle tire and a
compact spare tire sidewall. Passenger (P-Metric) Tire Example
(1) Tire Size :
The tire size is a
combination of letters and
numbers used to define a
particular tire's width, height,
aspect ratio, construction type,
and service description. See the
“ Tire Size ” illustration later in this
section.
(2) TPC Spec (Tire
Performance Criteria
Specification) :
Original
equipment tires designed to
GM's specific tire performance
criteria have a TPC specification
code molded onto the sidewall.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/6/15
Vehicle Care 303(3) Tire Identification Number
(TIN) :
The letters and numbers
following the DOT (Department
of Transportation) code are the
Tire Identification Number (TIN).
The TIN shows the
manufacturer and plant code,
tire size, and date the tire was
manufactured. The TIN is
molded onto both sides of the
tire, although only one side may
have the date of manufacture.
(4) Maximum Cold Inflation
Load Limit :
Maximum load that
can be carried and the
maximum pressure needed to
support that load.
(5) Tire Inflation :
The
temporary use tire or compact
spare tire should be inflated to
420 kPa (60 psi). For more
information on tire pressure and
inflation see Tire
Pressure 0 306 .
(6) Tire Size :
A combination of
letters and numbers define a
tire's width, height, aspect ratio, construction type, and service
description. The letter T as the
first character in the tire size
means the tire is for temporary
use only.
(7) TPC Spec (Tire
Performance Criteria
Specification) :
Original
equipment tires designed to
GM's specific tire performance
criteria have a TPC specification
code molded onto the sidewall.
GM's TPC specifications meet or
exceed all federal safety
guidelines.
Tire Designations Tire Size
The following is an example of a
typical passenger vehicle
tire size. (1) Passenger (P-Metric) Tire :
The United States version of a
metric tire sizing system. The
letter P as the first character in
the tire size means a passenger
vehicle tire engineered to
standards set by the U.S. Tire
and Rim Association.
(2) Tire Width :
The three-digit
number indicates the tire section
width in millimeters from
sidewall to sidewall.
(3) Aspect Ratio :
A two-digit
number that indicates the tire
height-to-width measurements.
For example, if the tire size
aspect ratio is 60, as shown in
item 3 of the illustration, it would
mean that the tire's sidewall is
60 percent as high as it is wide.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/6/15
304 Vehicle Care (4) Construction Code :
A letter
code is used to indicate the type
of ply construction in the tire.
The letter R means radial ply
construction; the letter D means
diagonal or bias ply
construction; and the letter B
means belted-bias ply
construction.
(5) Rim Diameter :
Diameter of
the wheel in inches.
(6) Service Description :
These
characters represent the load
index and speed rating of the
tire. The load index represents
the load carrying capacity a tire
is certified to carry. The speed
rating is the maximum speed a
tire is certified to carry a load.
Tire Terminology and
Definitions Air Pressure :
The amount of
air inside the tire pressing
outward on each square inch of the tire. Air pressure is
expressed in kPa (kilopascal)
or psi (pounds per square inch).
Accessory Weight :
The
combined weight of optional
accessories. Some examples of
optional accessories are
automatic transmission, power
windows, power seats, and air
conditioning.
Aspect Ratio :
The relationship
of a tire's height to its width.
Belt :
A rubber coated layer of
cords between the plies and the
tread. Cords may be made from
steel or other reinforcing
materials.
Bead :
The tire bead contains
steel wires wrapped by steel
cords that hold the tire onto
the rim.
Bias Ply Tire :
A pneumatic tire
in which the plies are laid at
alternate angles less than
90 degrees to the centerline of
the tread. Cold Tire Pressure :
The
amount of air pressure in a tire,
measured in kPa (kilopascal)
or psi (pounds per square inch)
before a tire has built up heat
from driving. See Tire
Pressure 0 306 .
Curb Weight :
The weight of a
motor vehicle with standard and
optional equipment including the
maximum capacity of fuel, oil,
and coolant, but without
passengers and cargo.
DOT Markings :
A code molded
into the sidewall of a tire
signifying that the tire is in
compliance with the U.S.
Department of Transportation
(DOT) Motor Vehicle Safety
Standards. The DOT code
includes the Tire Identification
Number (TIN), an alphanumeric
designator which can also
identify the tire manufacturer,
production plant, brand, and
date of production.