2016 CADILLAC CT6 check engine

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
Vehicle Care 271When to Add Engine Oil
2.0L L4 Engine
3.0L V6 Twin Turbo Engine Shown,
3.6L V6 Engine Similar
If the oil is below the cross-hatched
area at the tip of the dipstick, add
1 L (1 qt) of the recommended oil
and then recheck the level. See
“ Selecting the Right Engine Oil ” in
this section for an explanation of
what kind of oil to use. For engine
oil crankcase capacity, see
Capacities and Specifications 0 358 . CautionDo not add too much oil. Oil
levels above or below the
acceptable operating range
shown on the dipstick are harmful
to the engine. If you find that you
have an oil level above the
operating range, i.e., the engine
has so much oil that the oil level
gets above the cross-hatched
area that shows the proper
operating range, the engine could
be damaged. You should drain
out the excess oil or limit driving
of the vehicle and seek a service
professional to remove the
excess amount of oil.
See Engine Compartment Overview
0 265 for the location of the engine
oil fill cap.
Add enough oil to put the level
somewhere in the proper operating
range. Push the dipstick all the way
back in when through. Selecting the Right Engine Oil Selecting the right engine oil
depends on both the proper oil
specification and viscosity grade.
See Recommended Fluids and
Lubricants 0 353 .
Specification
Ask for and use engine oils that
meet the dexos1 ™ specification.
Engine oils that have been
approved by GM as meeting the
dexos1 specification are marked
with the dexos1 approved logo. See
www.gmdexos.com.
Caution
Failure to use the recommended
engine oil or equivalent can result
in engine damage not covered by
the vehicle warranty.

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 273If the system is ever reset
accidentally, the oil must be
changed at 5 000 km (3,000 mi)
since the last oil change.
Remember to reset the oil life
system whenever the oil is changed.
How to Reset the Engine Oil
Life System Reset the system whenever the
engine oil is changed so that the
system can calculate the next
engine oil change. To reset the
system:
1. Using the DIC buttons, display
REMAINING OIL LIFE on the
DIC. See Driver Information
Center (DIC) 0 140 and Engine
Oil Messages 0 149 .
2. Press and hold SEL to clear
the CHANGE ENGINE OIL
SOON message and reset the
oil life at 100%.
Be careful not to reset the oil
life display accidentally at any
time other than after the oil is
changed. It cannot be reset
accurately until the next oil
change. The oil life system can also be reset
as follows:
1. Turn the ignition on with the
engine off.
2. Fully press and release the
accelerator pedal three times
within five seconds.
If the CHANGE ENGINE OIL
SOON message is not on, the
system is reset.
The system is reset when the
CHANGE ENGINE OIL SOON
message is off.
If the CHANGE ENGINE OIL SOON
message comes back on when the
vehicle is started, the engine oil life
system has not been reset. Repeat
the procedure.
Automatic Transmission
Fluid How to Check Automatic
Transmission Fluid
It is not necessary to check the
transmission fluid level.
A transmission fluid leak is the only
reason for fluid loss. If a leak occurs, take the vehicle to your
dealer and have it repaired as soon
as possible.
The vehicle is not equipped with a
transmission fluid level dipstick.
There is a special procedure for
checking and changing the
transmission fluid. Because this
procedure is difficult, this should be
done at the dealer. Contact your
dealer for additional information.
Change the fluid and filter at the
intervals listed in Maintenance
Schedule 0 344 , and be sure to use
the fluid listed in Recommended
Fluids and Lubricants 0 353 .
Engine Air Cleaner/Filter The engine air cleaner/filter is in the
engine compartment. See Engine
Compartment Overview 0 265 .
When to Inspect the Engine Air
Cleaner/Filter
For intervals on changing and
inspecting the engine air cleaner/
filter, see Maintenance
Schedule 0 344 .

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
278 Vehicle Care Checking Coolant The vehicle must be on a level
surface when checking the coolant
level.
2.0L L4 and 3.0L V6 Engine
Coolant Surge Tank 3.6L V6 Engine Coolant
Surge Tank
Check to see if coolant is visible in
the coolant surge tank. If the coolant
inside the coolant surge tank is
boiling, do not do anything else until
it cools down. See Engine
Overheating 0 280 .
The coolant surge tank is in the
engine compartment on the
passenger side of the vehicle. See
Engine Compartment
Overview 0 265 . How to Add Coolant to the
Coolant Surge Tank
CautionThis vehicle has a specific
coolant fill procedure. Failure to
follow this procedure could cause
the engine to overheat and be
severely damaged.
If no problem is found, check to see
if coolant is visible in the coolant
surge tank. If coolant is visible but
the coolant level mark is not visible,
add a 50/50 mixture of clean,
drinkable water and DEX-COOL
coolant at the coolant surge tank to
the top rib on the middle of the tank,
but be sure the cooling system,
including the coolant surge tank
pressure cap, is cool before this is
done. See Engine
Overheating 0 280 .

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