2018 CADILLAC CT6 Gas

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
252 DRIVING AND OPERATING
When following a vehicle and entering
a curve, ACC may not detect the
vehicle ahead and accelerate to the set
speed. When this happens, the vehicle
ahead indicator will not appear.
ACC may detect a vehicle that is not
in your lane and apply the brakes.
ACC may occasionally provide an alert
and/or braking that is considered
unnecessary. It could respond to
vehicles in different lanes, signs,
guardrails, and other stationary
objects when entering or exiting a
curve. This is normal operation. The
vehicle does not need service.Other Vehicle Lane Changes
ACC will not detect a vehicle ahead
until it is completely in the lane. The
brakes may need to be manually
applied.
Do Not Use ACC on Hills and When
Towing a Trailer
Do not use ACC when driving on steep
hills or when towing a trailer. For
towing capability, see
Trailer Towing
(PLUG-IN Only) 0293 orTrailer Towing
(Gasoline Only) 0293. ACC will not
detect a vehicle in the lane while
driving on steep hills. The driver will
often need to take over acceleration
and braking on steep hills, especially
when towing a trailer. If the brakes are
applied, the ACC disengages.
Disengaging ACC
There are three ways to
disengage ACC:
. Step lightly on the brake pedal.
. Press
*.
. Press
J.
Erasing Speed Memory
The ACC set speed is erased from
memory if
Jis pressed or if the
ignition is turned off.
Cleaning the Sensing System
The camera sensor on the windshield
behind the rearview mirror and the
radar sensors on the front of the

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
288 DRIVING AND OPERATING
Filling the Tank
{Warning
Fuel vapors and fuel fires burn
violently and can cause injury or
death.. To help avoid injuries to you
and others, read and follow
all the instructions on the
fuel pump island.
. Turn off the engine when
refueling.
. Keep sparks, flames, and
smoking materials away
from fuel.
. Do not leave the fuel pump
unattended.
. Do not use a cell phone while
refueling.
. Do not reenter the vehicle
while pumping fuel.
. Keep children away from the
fuel pump and never let
children pump fuel.
(Continued)
Warning (Continued)
.Fuel can spray out if the
refueling nozzle is inserted
too quickly. This spray can
happen if the tank is nearly
full, and is more likely in hot
weather. Insert the refueling
nozzle slowly and wait for any
hiss noise to stop prior to
beginning to flow fuel.
Opening the Fuel Door
(Gasoline Only)
To open the fuel door, push and
release the rearward center edge of
the door. If equipped, the fuel door is
locked when the vehicle doors are
locked. Press
Kon the RKE
transmitter to unlock.
Opening the Fuel Door
(PLUG-IN Only)
To refuel the PLUG-IN vehicle:
1. Press the fuel door button on the driver door for one second.
A WAIT TO REFUEL message
displays on the Driver
Information Center.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
DRIVING AND OPERATING 289
2. When the READY TO REFUELmessage displays, the fuel door
will unlock. To open the fuel
door, push and release the
rearward center edge of the door.
3. Complete refueling within 30 minutes of pressing the fuel
door button on the driver door.
If refueling after more than
30 minutes, press the fuel door
button again.
4. After refueling, close the fuel door.
Refueling the Vehicle
The vehicle has a capless fuel system
and does not have a fuel cap. The
filling nozzle must be fully inserted
and latched prior to starting fuel flow.
{Warning
Overfilling the fuel tank by more
than three clicks of a standard fill
nozzle may cause:
(Continued)
Warning (Continued)
.Vehicle performance issues,
including engine stalling and
damage to the fuel system.
. Fuel spills.
. Potential fuel fires.
Be careful not to spill fuel. Wait a few
seconds after you have finished
pumping before removing the nozzle.
Clean fuel from painted surfaces as
soon as possible. See Exterior Care
0 380.
{Warning
If a fire starts while you are
refueling, do not remove the nozzle.
Shut off the flow of fuel by shutting
off the pump or by notifying the
station attendant. Leave the area
immediately.
Filling the Tank with a Portable
Gas Can
If the vehicle runs out of fuel and
must be filled from a portable gas can:
1. Locate the capless funnel
adapter from within the vehicle.
2. Insert and latch the funnel into the capless fuel system.
{Warning
Attempting to refuel without using
the funnel adapter may cause fuel
spillage and damage the capless
fuel system. This could cause a fire
and you or others could be badly
burned and the vehicle could be
damaged.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
DRIVING AND OPERATING 291
.Then during the first 800 km
(500 mi) of trailer towing, do not
drive over 80 km/h (50 mph) and
do not make starts at full throttle.
. Vehicles can tow in D (Drive). Shift
the transmission to a lower gear if
the transmission shifts too often
under heavy loads and/or hilly
conditions.
. Do not use Adaptive Cruise
Control when towing.
. The Forward Automatic Braking
system should be set to Off when
towing. See Forward Automatic
Braking (FAB) 0262.
. The Front Pedestrian Braking
system should be set to Alert or
Off when towing. See Front
Pedestrian Braking (FPB) System
0 264.
. Turn off Parking Assist when
towing.{Warning
When towing a trailer, exhaust
gases may collect at the rear of the
vehicle and enter if the liftgate,
trunk/hatch, or rear-most window
is open.
When towing a trailer:
. Do not drive with the liftgate,
trunk/hatch, or rear-most
window open.
. Fully open the air outlets on
or under the instrument
panel.
. Also adjust the climate
control system to a setting
that brings in only outside air.
See “Climate Control Systems ”
in the Index.
For more information about carbon
monoxide, see Engine Exhaust
0 230.
Towing a trailer requires a certain
amount of experience. The
combination you are driving is longer
and not as responsive as the vehicle itself. Get acquainted with the
handling and braking of the rig before
setting out for the open road.
Before starting, check all trailer hitch
parts and attachments, safety chains,
electrical connectors, lamps, tires, and
mirrors. If the trailer has electric
brakes, start the combination moving
and then apply the trailer brake
controller by hand to be sure the
brakes work.
During the trip, check occasionally to
be sure that the load is secure and the
lamps and any trailer brakes
still work.
Following Distance
Stay at least twice as far behind the
vehicle ahead as you would when
driving the vehicle without a trailer.
This can help to avoid heavy braking
and sudden turns.
Passing
More passing distance is needed when
towing a trailer. The combination will
not accelerate as quickly and is longer
so it is necessary to go much farther
beyond the passed vehicle before
returning to the lane.

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 - 2/15/17
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