2018 CADILLAC CT6 service

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
286 DRIVING AND OPERATING
The following are the minimum
requirements for circuits used to
charge this vehicle:
.120 volts/15 amps
. 240 volts/20 amps
Charging equipment with a rating of
at least 240 volts/20 amps will provide
the fastest charging time and best
charging efficiency to recharge the
high voltage battery. 240 volt/40 amp
circuits provide flexibility for future
vehicle charging needs. Always follow
the charging equipment installation
instructions. Contact your dealer for
more information.
Caution
Do not use portable or stationary
backup generating equipment to
charge the vehicle. This may cause
damage to the vehicle's charging
system. Only charge the vehicle
from utility supplied power.
Fuel
GM recommends the use of TOP
TIER®detergent gasoline to keep the
engine cleaner and reduce engine
deposits. See www.toptiergas.com for a
list of TOP TIER detergent gasoline
marketers and applicable countries.
Do not use any fuel labeled E85 or
FlexFuel. Do not use gasoline with
ethanol levels greater than 15% by
volume.
For the 2.0L L4 turbo engine,
premium unleaded gasoline meeting
ASTM specification D4814 with a
posted octane rating of 93 is highly
recommended for best performance and fuel economy. Unleaded gasoline
with an octane rated as low as 87 can
be used. Using unleaded gasoline
rated below 93 octane, however, will
lead to reduced acceleration and fuel
economy. If knocking occurs, use a
gasoline rated at 93 octane as soon as
possible, otherwise, the engine could
be damaged. If heavy knocking is
heard when using gasoline with a
93 octane rating, the engine needs
service.
For the 3.6L V6 engine, use regular
unleaded gasoline meeting ASTM
specification D4814 with a posted
octane rating of 87 or higher. Do not
use gasoline with a posted octane
rating of less than 87, as this may
cause engine knock and will lower fuel
economy.
For the 3.0L twin turbo V6 engine, use
premium unleaded gasoline meeting
ASTM specification D4814 with a
posted octane rating of 93.
If unavailable, unleaded gasoline with
a posted octane rating of 91 may be
used, but with reduced performance
and fuel economy. If the octane is less
than 91, the engine could be damaged
and the repairs would not be covered

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
DRIVING AND OPERATING 287
by the vehicle warranty. If heavy
knocking is heard when using gasoline
rated at 93 octane, the engine needs
service.
Prohibited Fuels
Caution
Do not use fuels with any of the
following conditions; doing so may
damage the vehicle and void its
warranty:. For vehicles which are not
FlexFuel, fuel labeled greater
than 15% ethanol by volume,
such as mid-level ethanol
blends (16 –50% ethanol),
E85, or FlexFuel.
. Fuel with any amount of
methanol, methylal, and
aniline. These fuels can
corrode metal fuel system
parts or damage plastic and
rubber parts.
. Fuel containing metals such
as methylcyclopentadienyl
manganese tricarbonyl
(Continued)
Caution (Continued)
(MMT), which can damage
the emissions control system
and spark plugs.
. Fuel with a posted octane
rating of less than the
recommended fuel. Using this
fuel will lower fuel economy
and performance, and may
decrease the life of the
emissions catalyst.
California Fuel
Requirements
If the vehicle is certified to meet
California Emissions Standards, it is
designed to operate on fuels that meet
California specifications. See the
underhood emission control label.
If this fuel is not available in states
adopting California Emissions
Standards, the vehicle will operate
satisfactorily on fuels meeting federal
specifications, but emission control
system performance may be affected.
The malfunction indicator lamp could
turn on and the vehicle may not pass a smog-check test. See
Malfunction
Indicator Lamp (Check Engine Light)
0 143. If this occurs, return to your
authorized dealer for diagnosis. If it is
determined that the condition is
caused by the type of fuel used,
repairs may not be covered by the
vehicle warranty.
Fuels in Foreign Countries
The U.S., Canada, and Mexico post
fuel octane ratings in anti-knock index
(AKI). For fuel not to use in a foreign
country, see “Prohibited Fuels” inFuel
0 286.
Fuel Additives
To keep fuel systems clean, TOP TIER
detergent gasoline is recommended.
See Fuel 0286.
If TOP TIER detergent gasoline is not
available, one bottle of GM Fuel
System Treatment Cleaner added to
the fuel tank at every engine oil
change, can help. GM Fuel System
Treatment Cleaner is the only gasoline
additive recommended by General
Motors. It is available at your dealer.

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) -
2018 - crc - 2/14/17
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
296 VEHICLE CARE
Vehicle Care
General Information
General Information . . . . . . . . . . . . . 297
California Proposition65 Warning . . . . . . . . . . . . . . . . . . . . . 297
California Perchlorate Materials Requirements . . . . . . . . . . . . . . . . . . . 297
Accessories and Modifications . . . . . . . . . . . . . . . . . . . 298
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . . . . . . 298
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . . . . . . 300
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . 307
Engine Oil Life System . . . . . . . . . . . 309
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310
Engine Air Cleaner/Filter . . . . . . . . . 311
Cooling System (Gasoline Only) . . . . . . . . . . . . . . . . . 312
Cooling System (PLUG-IN Only) . . . . . . . . . . . . . . . . . 316
Engine Overheating . . . . . . . . . . . . . . 321
Washer Fluid . . . . . . . . . . . . . . . . . . . . . 322
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . 323 Battery - North America . . . . . . . . . 324
All-Wheel Drive . . . . . . . . . . . . . . . . . . 326
Starter Switch Check . . . . . . . . . . . . . 326
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327
Park Brake and P (Park) Mechanism Check . . . . . . . . . . . . . . 327
Wiper Blade Replacement . . . . . . . 327
Windshield Replacement . . . . . . . . 328
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . 328
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . . . . . 329
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . 330
LED Lighting . . . . . . . . . . . . . . . . . . . . . 330
License Plate Lamp . . . . . . . . . . . . . . 330
Replacement Bulbs . . . . . . . . . . . . . . . 330
Electrical System
Electrical System Overload . . . . . . 331
Fuses and Circuit Breakers . . . . . . 331
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
Instrument Panel Fuse Block . . . . 335
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340 All-Season Tires . . . . . . . . . . . . . . . . . . 341
Winter Tires . . . . . . . . . . . . . . . . . . . . . . 341
Low-Profile Tires . . . . . . . . . . . . . . . . . 342
Summer Tires . . . . . . . . . . . . . . . . . . . . 342
Tire Sidewall Labeling . . . . . . . . . . . 342
Tire Designations . . . . . . . . . . . . . . . . . 344
Tire Terminology and
Definitions . . . . . . . . . . . . . . . . . . . . . . 345
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . 347
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . . . . . . 349
Tire Pressure Monitor System . . . 349
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . . . . . . 350
Tire Inspection . . . . . . . . . . . . . . . . . . . 353
Tire Rotation . . . . . . . . . . . . . . . . . . . . . 353
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355
Buying New Tires . . . . . . . . . . . . . . . . 355
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . . . . . 357
Uniform Tire Quality Grading . . . 357
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . . . . . . 359
Wheel Replacement . . . . . . . . . . . . . . 359
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . 360
If a Tire Goes Flat . . . . . . . . . . . . . . . . 360
Tire Sealant and Compressor Kit . . . . . . . . . . . . . . . . . 362
Storing the Tire Sealant and Compressor Kit . . . . . . . . . . . . . . . . . 368

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/15/17
VEHICLE CARE 297
Tire Changing . . . . . . . . . . . . . . . . . . . . . 368
Compact Spare Tire . . . . . . . . . . . . . . 373
Jump Starting
Jump Starting - NorthAmerica . . . . . . . . . . . . . . . . . . . . . . . . . 374
Towing the Vehicle
Towing the Vehicle . . . . . . . . . . . . . . . 376
Recreational Vehicle Towing . . . . 378
Appearance Care
Exterior Care . . . . . . . . . . . . . . . . . . . . . . 380
Interior Care . . . . . . . . . . . . . . . . . . . . . . 384
Floor Mats . . . . . . . . . . . . . . . . . . . . . . . . 387
General Information
For service and parts needs, visit your
dealer. You will receive genuine GM
parts and GM-trained and supported
service people.
Genuine GM parts have one of these
marks:
California Proposition
65 Warning
{Warning
Most motor vehicles, including this
one, as well as many of its service
parts and fluids, contain and/or
emit chemicals known to the State
of California to cause cancer and
birth defects or other reproductive
harm. Engine exhaust, many parts
and systems, many fluids, and
some component wear by-products
contain and/or emit these
chemicals. For more information go
to www.P65Warnings.ca.gov/
passenger-vehicle.
See Battery - North America 0324 and
Jump Starting - North America 0374
and the back cover.
California Perchlorate
Materials Requirements
Certain types of automotive
applications, such as airbag initiators,
seat belt pretensioners, and lithium

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
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298 VEHICLE CARE
batteries contained in Remote Keyless
Entry transmitters, may contain
perchlorate materials. Special
handling may be necessary. For
additional information, see
www.dtsc.ca.gov/hazardouswaste/
perchlorate.
Accessories and
Modifications
Adding non-dealer accessories or
making modifications to the vehicle
can affect vehicle performance and
safety, including such things as
airbags, 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 vehicle 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 095.
Vehicle Checks
Doing Your Own
Service Work
{Warning
It can be dangerous to work on
your vehicle if you do not have the
proper knowledge, service manual,
tools, or parts. Always follow
owner’s 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 0416.
This vehicle has an airbag system.
Before attempting to do your own
service work, see Servicing 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.