2018 CADILLAC CT6 maintenance

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
228 DRIVING AND OPERATING
Once the vehicle is refueled, or the
malfunction is corrected, the engine
will start the next time the vehicle is
turned on to perform a self test, and
DIC messages will not be displayed.
Once the engine starts successfully,
normal operation will continue with
either electric propulsion or with the
engine running. The engine will stop
running after the self test is
completed, and based on the current
mode of operation.
Maintenance Modes
Engine Maintenance Mode (EMM)
EMM runs the engine to keep it in
good working condition after
approximately six weeks of no or very
limited engine operation. EMM will
force the engine to run, even if there
is a charge to power the vehicle.
When EMM is needed, the EMM
Request screen appears on the
infotainment display at vehicle start.
If Yes is selected, EMM will begin. The
engine will not start until after a short
delay once shifted into D (Drive). The
engine will run for a set amount of
time without turning off. During
EMM, a DIC message displays to show
the EMM percentage complete.
If No is selected, the EMM Request
screen will appear when the vehicle is
next started. The EMM request can be
delayed for up to one day.
If the EMM request was delayed for
one day, EMM will automatically start
the engine at the next vehicle start.
The engine will not start until after a
short delay once shifted into D (Drive).An EMM Notification screen will
appear in the infotainment display.
If the vehicle is shut off during EMM,
it will restart the next time the vehicle
is driven.
A message displays to indicate that
EMM is active.
If EMM is required and the fuel level
is low, EMM may eventually empty
the fuel tank if fuel is not added. This

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
DRIVING AND OPERATING 229
will result in reduced, or no power. An
adequate fuel level must be
maintained in the vehicle to keep it
operational.
Fuel Maintenance Mode (FMM)
FMM tracks average fuel age. Old fuel
can cause engine problems. If low
engine usage causes average fuel age
to exceed approximately one year,
FMM will run the engine to use up
the old fuel. The engine will run until
enough fresh fuel is added to bring
the average fuel age into an
acceptable range. Allowing more old
fuel to be used up by FMM and
adding a larger amount of fresh fuel
will maximize the length of time
before another fuel maintenance
mode is needed. During FMM the
engine may turn on and off.
When FMM is needed, the FMM
Request screen appears on the
infotainment display at vehicle start.
If Yes is selected, FMM will begin. The
engine will not start until after a short
delay once shifted into D (Drive). FMM
will automatically continue at each
vehicle start until fresh fuel is added.
If No is selected, the FMM Request
screen will appear when the vehicle is
next started. The FMM request can be
delayed for only one day.If the FMM request was delayed for
one day, FMM will start at the next
vehicle start and display the FMM
Notification screen on the
infotainment display. The engine will
not start until after a short delay once
shifted into D (Drive).
If FMM is required and the fuel level
is low, FMM may eventually empty
the fuel tank if fuel is not added. This
will result in reduced, or no power. An
adequate fuel level must be
maintained in the vehicle to keep it
operational. After FMM has run it is
recommended to fill the fuel tank.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
DRIVING AND OPERATING 293
4. Reapply the brake pedal. Thenapply the parking brake and shift
into P (Park).
5. Release the brake pedal.
Leaving After Parking on a Hill
1. Apply and hold the brake pedal.
2. Start the engine.
3. Shift into a gear.
4. Release the parking brake.
5. Let up on the brake pedal.
6. Drive slowly until the trailer is clear of the chocks.
7. Stop and have someone pick up and store the chocks.
Maintenance when Trailer
Towing
The vehicle needs service more often
when pulling a trailer. . Things that
are especially important in trailer
operation are automatic transmission
fluid, engine oil, axle lubricant, belts,
cooling system, and brake system. It is
a good idea to inspect these before
and during the trip. Check periodically to see that all hitch
nuts and bolts are tight.
Trailer Towing
(PLUG-IN Only)
The vehicle is neither designed nor
intended to tow a trailer.
Trailer Towing
(Gasoline Only)
Before pulling a trailer, three
important considerations have to do
with weight:
.
Weight of the trailer.
. Weight of the trailer tongue.
. Total weight on your vehicle's
tires.
Weight of the Trailer
How heavy can a trailer safely be?
It should never weigh more than
454 kg (1,000 lb). But even that can be
too heavy.
Safe trailering requires monitoring the
weight, speed, altitude, road grades,
outside temperature, the dimensions of the front of the trailer, and how
frequently the vehicle is used to pull a
trailer. Take into consideration any
special equipment on the vehicle, and
the amount of tongue weight the
vehicle can carry. See
“Weight of the
Trailer Tongue ”later in this section
for more information.
Trailer weight rating (TWR) is
calculated assuming the tow vehicle
has the driver, a front seat passenger,
and all required trailering equipment.
Weight of additional optional
equipment, passengers, and cargo in
the tow vehicle must be subtracted
from the trailer weight rating.
Ask your dealer for trailering
information or advice, or write us at
our Customer Assistance Offices. See
Customer Assistance Offices 0410.Weight of the Trailer Tongue
The tongue weight load (1) of any
trailer is very important because it is
also part of the vehicle weight. The
Gross Vehicle Weight (GVW) includes
the curb weight of the vehicle, any
cargo carried in it, and the people who
will be riding in the vehicle, as well as
trailer tongue weight. Vehicle options,

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
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DRIVING AND OPERATING 295
Because the vehicle has antilock
brakes, do not tap into the vehicle's
brake system. If this is done, both
brake systems will not work well or
at all.Conversions and
Add-Ons
Add-On Electrical
Equipment
{Warning
The Data Link Connector (DLC) is
used for vehicle service and
Emission Inspection/Maintenance
testing. SeeMalfunction Indicator
Lamp (Check Engine Light) 0143.
A device connected to the DLC —
such as an aftermarket fleet or
driver-behavior tracking device —
may interfere with vehicle systems.
This could affect vehicle operation
and cause a crash. Such devices
may also access information stored
in the vehicle’s systems.
Caution
Some electrical equipment can
damage the vehicle or cause
components to not work and would
not be covered by the vehicle
warranty. Always check with your
dealer before adding electrical
equipment.
Add-on equipment can drain the
vehicle's 12-volt battery, even if the
vehicle is not operating.
The vehicle has an airbag system.
Before attempting to add anything
electrical to the vehicle, see Servicing
the Airbag-Equipped Vehicle 095 and
Adding Equipment to the
Airbag-Equipped Vehicle 095.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/15/17
VEHICLE CARE 299
Keep a record with all parts receipts
and list the mileage and the date of
any service work performed. See
Maintenance Records0402.
Caution
Even small amounts of
contamination can cause damage to
vehicle systems. Do not allow
contaminants to contact the fluids,
reservoir caps, or dipsticks.
Hood
{Warning
Gas struts and other metal
components under the hood can get
hot after running the engine. Do
not touch these components 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.
Caution
Be 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-11292458) -
2018 - crc - 2/15/17
VEHICLE CARE 311
Change the fluid and filter at the
intervals listed inMaintenance
Schedule 0390, and be sure to use the
fluid listed in Recommended Fluids and
Lubricants 0399.
Engine Air Cleaner/Filter
The engine air cleaner/filter is in the
engine compartment. See Engine
Compartment Overview 0300.
When to Inspect the Engine Air
Cleaner/Filter
For intervals on changing and
inspecting the engine air cleaner/filter,
see Maintenance Schedule 0390.
How to Inspect the Engine Air
Cleaner/Filter
Do not start the engine or have the
engine running with the engine air
cleaner/filter housing open. Before
removing the engine air cleaner/filter,
make sure that the engine air cleaner/
filter housing and nearby components
are free of dirt and debris. Remove the
engine air cleaner/filter. Lightly tap
and shake the engine air cleaner/filter
(away from the vehicle), to release
loose dust and dirt. Inspect the engine air cleaner/filter for damage, and
replace if damaged. Do not clean the
engine air cleaner/filter or
components with water or
compressed air.
To inspect or replace the engine air
cleaner/filter:2.0L L4 Gasoline Only Engine Shown,
2.0L L4 PLUG-IN Engine Similar
1. Remove the five screws on top of the engine air cleaner/filter cover.
2. Lift the engine air cleaner/filter cover open on the hinge.
3. Lift and remove the engine air cleaner/filter. 4. Inspect or replace the engine air
cleaner/filter.
5. Reverse Steps 1–3 to reinstall the engine air cleaner/filter cover.
3.0L V6 Engine
1. Remove the 10 screws on top of the engine air cleaner/filter cover
to gain access to both air
cleaner/filters.
2. Lift the engine air cleaner/filter cover open on the hinge.
3. Lift and remove one or both engine air cleaner/filters.
4. Inspect or replace one or both engine air cleaner/filters.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/15/17
314 VEHICLE CARE
Engine Coolant
The engine cooling system in the
vehicle is filled with a DEX-COOL
engine coolant mixture. This coolant
needs to be checked and replaced at
appropriate intervals. SeeMaintenance
Schedule 0390.
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 0321.
What to Use
{Warning
Plain water, or other liquids such as
alcohol, can boil before the proper
coolant mixture will. With plain
water or the wrong mixture, the
engine could get too hot but there
would not be an 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. 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
temperatureCaution
Do not use anything other than a
mix of DEX-COOL coolant that
meets GM Standard GMW3420 and
clean, drinkable water. Anything
else can cause damage to the
vehicle’s engine cooling system and
vehicle, which would not be covered
by the vehicle warranty. 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.
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

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/15/17
VEHICLE CARE 317
Engine Coolant
The engine cooling system in the
vehicle is filled with GM Premix
DEX-COOL coolant. This coolant
needs to be checked and replaced at
appropriate intervals. SeeMaintenance
Schedule 0390.
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 0321.
What to Use
{Warning
Plain water, or other liquids such as
alcohol, can boil before the proper
coolant mixture will. With plain
water or the wrong mixture, the
engine could get too hot but there
would not be an overheat warning.
The engine could catch fire and you
or others could be burned.
Use GM Premix 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
Caution
Do not use anything other than GM
Premix DEX-COOL coolant.
Anything else can cause damage to
the PLUG-IN cooling system
components and the vehicle, which
would not be covered by the vehicle
warranty.
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.
Checking Coolant
The vehicle must be on a level surface
when checking the coolant level.
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
0 321.