
Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/6/15
Driving and Operating 257necessary to go much farther
beyond the passed vehicle before
returning to the lane.
Backing Up Hold the bottom of the steering
wheel with one hand. To move the
trailer to the left, move that hand to
the left. To move the trailer to the
right, move your hand to the right.
Always back up slowly and,
if possible, have someone
guide you.
Making Turns
CautionMaking very sharp turns while
trailering could cause the trailer to
come in contact with the vehicle.
The vehicle could be damaged.
Avoid making very sharp turns
while trailering.
When turning with a trailer, make
wider turns than normal. Do this so
the trailer will not strike soft
shoulders, curbs, road signs, trees, or other objects. Avoid jerky or
sudden maneuvers. Signal well in
advance.
If the trailer turn signal bulbs burn
out, the arrows on the instrument
cluster will still flash for turns. It is
important to check occasionally to
be sure the trailer bulbs are still
working.
Driving on Grades Reduce speed and shift to a lower
gear before starting down a long or
steep downgrade. If the
transmission is not shifted down, the
brakes might get hot and no longer
work well.
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.
When towing at high altitude on
steep uphill grades, consider the
following: Engine coolant will boil at
a lower temperature than at normal
altitudes. If the engine is turned off
immediately after towing at high
altitude on steep uphill grades, the vehicle may show signs similar to
engine overheating. To avoid this,
let the engine run while parked,
preferably on level ground, with the
automatic transmission in P (Park)
for a few minutes before turning the
engine off. If the overheat warning
comes on, see Engine
Overheating 0 280 .
Parking on Hills
{ WarningParking the vehicle on a hill with
the trailer attached can be
dangerous. If something goes
wrong, the rig could start to move.
People can be injured, and both
the vehicle and the trailer can be
damaged. When possible, always
park the rig on a flat surface.
If parking the rig on a hill:
1. Press the brake pedal, but do
not shift into P (Park) yet. Turn
the wheels into the curb if
facing downhill or into traffic if
facing uphill.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/6/15
Vehicle Care 261
Vehicle Care General Information General Information . . . . . . . . . . 262
California Proposition
65 Warning . . . . . . . . . . . . . . . . . 262
California Perchlorate
Materials Requirements . . . . . 262
Accessories and
Modifications . . . . . . . . . . . . . . . . 262
Vehicle Checks Doing Your Own
Service Work . . . . . . . . . . . . . . . 263
Hood . . . . . . . . . . . . . . . . . . . . . . . . . 264
Engine Compartment
Overview . . . . . . . . . . . . . . . . . . . . 265
Engine Oil . . . . . . . . . . . . . . . . . . . . 270
Engine Oil Life System . . . . . . . 272
Automatic Transmission
Fluid . . . . . . . . . . . . . . . . . . . . . . . . 273
Engine Air Cleaner/Filter . . . . . . 273
Cooling System . . . . . . . . . . . . . . 275
Engine Coolant . . . . . . . . . . . . . . . 277
Engine Overheating . . . . . . . . . . 280
Washer Fluid . . . . . . . . . . . . . . . . . 281
Brakes . . . . . . . . . . . . . . . . . . . . . . . 282
Brake Fluid . . . . . . . . . . . . . . . . . . . 283
Battery - North America . . . . . . 284
All-Wheel Drive . . . . . . . . . . . . . . . 284 Starter Switch Check . . . . . . . . . 285
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 285
Park Brake and P (Park)
Mechanism Check . . . . . . . . . . 286
Wiper Blade Replacement . . . . 286
Windshield Replacement . . . . . 287
Headlamp Aiming Headlamp Aiming . . . . . . . . . . . . 287
Bulb Replacement Bulb Replacement . . . . . . . . . . . . 288
LED Lighting . . . . . . . . . . . . . . . . . 288
License Plate Lamp . . . . . . . . . . 288
Replacement Bulbs . . . . . . . . . . . 289
Electrical System Electrical System Overload . . . 289
Fuses and Circuit Breakers . . . 290
Engine Compartment Fuse
Block . . . . . . . . . . . . . . . . . . . . . . . . 290
Instrument Panel Fuse
Block . . . . . . . . . . . . . . . . . . . . . . . . 293
Rear Compartment Fuse
Block . . . . . . . . . . . . . . . . . . . . . . . . 295
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 299
All-Season Tires . . . . . . . . . . . . . . 300
Winter Tires . . . . . . . . . . . . . . . . . . 300 Low-Profile Tires . . . . . . . . . . . . . 300
Summer Tires . . . . . . . . . . . . . . . . 301
Tire Sidewall Labeling . . . . . . . . 301
Tire Designations . . . . . . . . . . . . . 303
Tire Terminology and
Definitions . . . . . . . . . . . . . . . . . . 304
Tire Pressure . . . . . . . . . . . . . . . . . 306
Tire Pressure for High-Speed
Operation . . . . . . . . . . . . . . . . . . . 308
Tire Pressure Monitor
System . . . . . . . . . . . . . . . . . . . . . . 308
Tire Pressure Monitor
Operation . . . . . . . . . . . . . . . . . . . 309
Tire Inspection . . . . . . . . . . . . . . . . 312
Tire Rotation . . . . . . . . . . . . . . . . . 313
When It Is Time for New
Tires . . . . . . . . . . . . . . . . . . . . . . . . 314
Buying New Tires . . . . . . . . . . . . . 315
Different Size Tires and
Wheels . . . . . . . . . . . . . . . . . . . . . . 316
Uniform Tire Quality
Grading . . . . . . . . . . . . . . . . . . . . . 316
Wheel Alignment and Tire
Balance . . . . . . . . . . . . . . . . . . . . . 318
Wheel Replacement . . . . . . . . . . 318
Tire Chains . . . . . . . . . . . . . . . . . . . 319
If a Tire Goes Flat . . . . . . . . . . . . 320
Tire Changing . . . . . . . . . . . . . . . . 321
Compact Spare Tire . . . . . . . . . . 326

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

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/6/15
Vehicle Care 289
Replacement Bulbs Exterior Lamp Bulb
Number
License
Plate Lamp 13588150
For replacement bulbs not listed
here, contact your dealer.
Electrical System Electrical System
Overload The vehicle has fuses and circuit
breakers to protect against an
electrical system overload.
When the current electrical load is
too heavy, the circuit breaker opens
and closes, protecting the circuit
until the current load returns to
normal or the problem is fixed. This
greatly reduces the chance of circuit
overload and fire caused by
electrical problems.
Fuses and circuit breakers protect
power devices in the vehicle.
Replace a bad fuse with a new one
of the identical size and rating.
If there is a problem on the road and
a fuse needs to be replaced, the
same amperage fuse can be
borrowed. Choose some feature of
the vehicle that is not needed to use
and replace it as soon as possible. Headlamp Wiring An electrical overload may cause
the lamps to go on and off, or in
some cases to remain off. Have the
headlamp wiring checked right away
if the lamps go on and off or
remain off.
Windshield Wipers If the wiper motor overheats due to
heavy snow or ice, the windshield
wipers will stop. Wiper function is
available immediately after the wiper
switch is set to off, and back to on.
To protect the wiper motor from
overheating, the wipers may slow
down when the windshield is dry for
a long period of time. If a period of
dry operation, or little moisture,
exceeds 10 minutes, the wipers
may switch to intermittent operation,
and remain there. When moisture is
again detected on the windshield,
wiper operation will return to the
operator selected speed.
Although the circuit is protected
from electrical overload, overload
due to heavy snow or ice may
cause wiper linkage damage.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/6/15
Vehicle Care 299
Wheels and Tires Tires Every new GM vehicle has
high-quality tires made by a
leading tire manufacturer. See
the warranty manual for
information regarding the tire
warranty and where to get
service. For additional
information refer to the tire
manufacturer.
{ Warning.
Poorly maintained and
improperly used tires are
dangerous..
Overloading the tires can
cause overheating as a
result of too much
flexing. There could be a
blowout and a serious
crash. See Vehicle Load
Limits 0 198 .
(Continued) Warning (Continued) .
Underinflated tires pose
the same danger as
overloaded tires. The
resulting crash could
cause serious injury.
Check all tires frequently
to maintain the
recommended pressure.
Tire pressure should be
checked when the tires
are cold. .
Overinflated tires are
more likely to be cut,
punctured, or broken by
a sudden impact — such
as when hitting a pothole.
Keep tires at the
recommended pressure.
.
Worn or old tires can
cause a crash. If the
tread is badly worn,
replace them.
(Continued) Warning (Continued) .
Replace any tires that
have been damaged by
impacts with potholes,
curbs, etc. .
Improperly repaired tires
can cause a crash. Only
the dealer or an
authorized tire service
center should repair,
replace, dismount, and
mount the tires. .
Do not spin the tires in
excess of 56 km/h
(35 mph) on slippery
surfaces such as snow,
mud, ice, etc. Excessive
spinning may cause the
tires to explode.
See Tire Pressure for
High-Speed Operation 0 308 for
inflation pressure adjustment for
high-speed driving.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/6/15
306 Vehicle Care Sidewall :
The portion of a tire
between the tread and the bead.
Speed Rating :
An
alphanumeric code assigned to
a tire indicating the maximum
speed at which a tire can
operate.
Traction :
The friction between
the tire and the road surface.
The amount of grip provided.
Tread :
The portion of a tire that
comes into contact with
the road.
Treadwear Indicators :
Narrow
bands, sometimes called wear
bars, that show across the tread
of a tire when only 1.6 mm
(1/16 in) of tread remains. See
When It Is Time for New
Tires 0 314 .
UTQGS (Uniform Tire Quality
Grading Standards) :
A tire
information system that provides
consumers with ratings for a
tire's traction, temperature, and
treadwear. Ratings are determined by tire
manufacturers using
government testing procedures.
The ratings are molded into the
sidewall of the tire. See Uniform
Tire Quality Grading 0 316 .
Vehicle Capacity Weight :
The
number of designated seating
positions multiplied by
68 kg (150 lb) plus the rated
cargo load. See Vehicle Load
Limits 0 198 .
Vehicle Maximum Load on the
Tire :
Load on an individual tire
due to curb weight, accessory
weight, occupant weight, and
cargo weight.
Vehicle Placard :
A label
permanently attached to a
vehicle showing the vehicle
capacity weight and the original
equipment tire size and
recommended inflation pressure.
See “ Tire and Loading
Information Label ” under Vehicle
Load Limits 0 198 . Tire Pressure Tires need the correct amount of
air pressure to operate
effectively.
Caution
Neither tire underinflation nor
overinflation is good.
Underinflated tires, or tires
that do not have enough air,
can result in: .
Tire overloading and
overheating which could
lead to a blowout. .
Premature or
irregular wear. .
Poor handling. .
Reduced fuel economy.
Overinflated tires, or tires that
have too much air, can
result in:
.
Unusual wear.
(Continued)