
Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/6/15
Vehicle Care 263airbags, braking, stability, ride and
handling, emissions systems,
aerodynamics, durability, and
electronic systems like antilock
brakes, traction control, and stability
control. These accessories or
modifications could even cause
malfunction or damage not covered
by the vehicle warranty.
Damage to suspension components
caused by modifying vehicle height
outside of factory settings will not be
covered by the warranty. Damage to vehicle components
resulting from modifications or the
installation or use of non-GM
certified parts, including control
module or software modifications, is
not covered under the terms of the
vehicle warranty and may affect
remaining warranty coverage for
affected parts.
GM Accessories are designed to
complement and function with other
systems on the vehicle. See your
dealer to accessorize the vehicle
using genuine GM Accessories
installed by a dealer technician.
Also, see Adding Equipment to the
Airbag-Equipped Vehicle 0 86 .Vehicle Checks Doing Your Own
Service Work
{ WarningIt can be dangerous to work on
your vehicle if you do not have
the proper knowledge, service
manual, tools, or parts. Always
follow owner manual procedures
and consult the service manual
for your vehicle before doing any
service work.
If doing some of your own service
work, use the proper service
manual. It tells you much more
about how to service the vehicle
than this manual can. To order the
proper service manual, see Service
Publications Ordering
Information 0 370 .
This vehicle has an airbag system.
Before attempting to do your own
service work, see Servicing the
Airbag-Equipped Vehicle 0 86 .

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/13/15
264 Vehicle Care Keep a record with all parts receipts
and list the mileage and the date of
any service work performed. See
Maintenance Records 0 356 .
CautionEven small amounts of
contamination can cause damage
to vehicle systems. Do not allow
contaminants to contact the fluids,
reservoir caps, or dipsticks.
Hood
{ WarningGas struts and other hot metal
components under the hood can
get hot after running the engine.
Do not touch as they can burn
unprotected skin and could cause
serious injury.
Clear any snow from the hood
before opening. To open the hood:
1. Pull the hood release handle.
It is on the lower left side of the
instrument panel between the
door and the steering wheel.
2. Release the handle, then pull
the handle again to fully open
the hood.
3. Go to the front of the vehicle
and lift the hood open. CautionBe sure the hood is completely
closed before driving. Damage
may occur if it is not.
To close the hood:
1. Before closing the hood, be
sure all filler caps are properly
installed.
2. Lower the hood approximately
46 cm (18 in) from the closed
position.
3. Then push the front center of
the hood with a swift, firm
motion.
4. Check to make sure the hood
is closed. If not, release the
hood from inside and repeat
Steps 1 – 3.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/6/15
270 Vehicle Care 1. Engine Coolant Surge Tank
and Pressure Cap. See
Cooling System 0 275 .
2. Engine Air Cleaner/Filter 0 273 .
3. Engine Cooling Fan (Out of
View). See Cooling
System 0 275 .
4. Engine Oil Fill Cap. See
Engine Oil 0 270 .
5. Engine Oil Dipstick. See
Engine Oil 0 270 .
6. Remote Positive (+) Battery
Terminal. See Jump Starting -
North America 0 327 .
7. Engine Compartment Fuse
Block 0 290 .
8. Brake Fluid Reservoir. See
Brake Fluid 0 283 .
9. Windshield Washer Fluid
Reservoir. See Washer
Fluid 0 281 .
10. Remote Negative (-) Battery
Terminal. See Jump Starting -
North America 0 327 . Engine Oil To ensure proper engine
performance and long life, careful
attention must be paid to engine oil.
Following these simple, but
important steps will help protect
your investment:
.
Use engine oil approved to the
proper specification and of the
proper viscosity grade. See
“ Selecting the Right Engine Oil ”
in this section.
.
Check the engine oil level
regularly and maintain the
proper oil level. See “ Checking
Engine Oil ” and “ When to Add
Engine Oil ” later in this section.
.
Change the engine oil at the
appropriate time. See Engine Oil
Life System 0 272 .
.
Always dispose of engine oil
properly. See “ What to Do with
Used Oil ” in this section.
Checking Engine Oil
It is a good idea to check the engine
oil level at each fuel fill. In order to
get an accurate reading, the vehicle must be on level ground. The
engine oil dipstick handle is a loop.
See Engine Compartment Overview
0 265 for the location of the engine
oil dipstick.
1. If the engine has been running
recently, turn off the engine and
allow several minutes for the oil
to drain back into the oil pan.
Checking the oil level too soon
after engine shutoff will not
provide an accurate oil level
reading.
{ WarningThe engine oil dipstick handle
may be hot; it could burn you.
Use a towel or glove to touch the
dipstick handle.
2. Pull out the dipstick and wipe it
with a clean paper towel or
cloth, then push it back in all
the way. Remove it again,
keeping the tip down, and
check the level.

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 275
3.6L V6 Engine
1. Screws (6)
2. Bolts (3)
3. Diagonal Brace
1. Remove the three bolts (2) and
the diagonal brace (3).
2. Remove the six screws (1) on
top of the engine air cleaner/
filter cover.
3. Lift the engine air cleaner/filter
cover open on the hinge.
4. Lift and remove the engine air
cleaner/filter.
5. Inspect or replace the engine
air cleaner/filter. 6. Reverse Steps 1 – 4 to reinstall
the engine air cleaner/filter
cover and diagonal brace.
{ WarningOperating the engine with the air
cleaner/filter off can cause you or
others to be burned. The air
cleaner not only cleans the air; it
helps to stop flames if the engine
backfires. Use caution when
working on the engine and do not
drive with the air cleaner/filter off.
CautionIf the air cleaner/filter is off, dirt
can easily get into the engine,
which could damage it. Always
have the air cleaner/filter in place
when you are driving.
Cooling System The cooling system allows the
engine to maintain the correct
working temperature. 2.0L L4 Engine
1. Engine Coolant Surge Tank
and Pressure Cap
2. Engine Cooling Fan (Out
of View)

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/6/15
276 Vehicle Care
3.0L V6 Twin Turbo Engine
1. Engine Coolant Surge Tank
and Pressure Cap
2. Engine Cooling Fan (Out
of View) 3.6L V6 Engine
1. Engine Coolant Surge Tank
and Pressure Cap
2. Engine Cooling Fan (Out
of View)
{ Warning
An electric engine cooling fan
under the hood can start up even
when the engine is not running
and can cause injury. Keep
hands, clothing, and tools away
from any underhood electric fan. { WarningHeater and radiator hoses, and
other engine parts, can be very
hot. Do not touch them. If you do,
you can be burned.
Do not run the engine if there is a
leak. If you run the engine, it
could lose all coolant. That could
cause an engine fire, and you
could be burned. Get any leak
fixed before you drive the vehicle.
CautionUsing coolant other than
DEX-COOL ®
can cause
premature engine, heater core,
or radiator corrosion. In addition,
the engine coolant could require
changing sooner. Any repairs
would not be covered by the
vehicle warranty. Always use
DEX-COOL (silicate-free) coolant
in the vehicle.

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
Vehicle Care 279
{ WarningSteam and scalding liquids from a
hot cooling system can blow out
and burn you badly. Never turn
the cap when the cooling system,
including the surge tank pressure
cap, is hot. Wait for the cooling
system and surge tank pressure
cap to cool.
{ 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
overheat warning. The engine
could catch fire and you or others
(Continued) Warning (Continued) could be burned. Use a 50/
50 mixture of clean, drinkable
water and DEX-COOL coolant.
CautionIn cold weather, water can freeze
and crack the engine, radiator,
heater core, and other parts. Use
the recommended coolant and
the proper coolant mixture.
{ Warning
You can be burned if you spill
coolant on hot engine parts.
Coolant contains ethylene glycol
and it will burn if the engine parts
are hot enough. Do not spill
coolant on a hot engine.
1. Remove the coolant surge tank
pressure cap when the cooling
system, including the coolant surge tank pressure cap and
upper radiator hose, is no
longer hot.
Turn the pressure cap slowly
counterclockwise about
one-quarter of a turn. If you
hear a hiss, wait for that to
stop. This will allow any
pressure still left to be vented
out the discharge hose.
2. Keep turning the pressure cap
slowly and remove it.
3. Fill the coolant surge tank with
the proper mixture to the
indicated level mark.
4. With the coolant surge tank
pressure cap off, start the
engine and let it run until you
can feel the upper radiator
hose getting hot. Watch out for
the engine cooling fan.
By this time, the coolant level
inside the coolant surge tank
may be lower. If the level is
lower, add more of the proper
mixture to the coolant surge
tank until the level reaches the
indicated level mark.