heating CADILLAC CT6 2018 1.G User Guide

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
DRIVING AND OPERATING 223
The automatic engine stop/start
function can be disabled by
touching
hon the center stack.
When
hcomes on green in the
instrument cluster, the system is
active. The system is not active when
it comes on white with a slash
through it.
Engine Heater
Vehicles with the engine heater can
use this option in cold weather
conditions at or below −18 °C (0 °F) for
easier starting and better fuel
economy during engine warm-up. Plug
in the coolant heater at least four hours before starting your vehicle. An
internal thermostat in the plug-end of
the cord may exist which will prevent
engine heater operation at
temperatures above
−18 °C (0 °F).
{Warning
Do not plug in the engine block
heater while the vehicle is parked in
a garage or under a carport.
Property damage or personal injury
may result. Always park the vehicle
in a clear open area away from
buildings or structures.
To Use the Engine Heater
1. Turn off the engine.
2. Open the hood and unwrap the
electrical cord. The cord is
clipped to the diagonal brace on
the passenger side of the engine
compartment.
Check the heater cord for
damage. If it is damaged, do not
use it. See your dealer for a
replacement. Inspect the cord for
damage yearly. 3. Plug it into a normal, grounded
110-volt AC outlet.
{Warning
Improper use of the heater cord or
an extension cord can damage the
cord and may result in overheating
and fire.
. Plug the cord into a
three-prong electrical utility
receptacle that is protected by
a ground fault detection
function. An ungrounded
outlet could cause an electric
shock.
. Use a weatherproof,
heavy-duty, 15 amp-rated
extension cord if needed.
Failure to use the
recommended extension cord
in good operating condition,
or using a damaged heater or
extension cord, could make it
(Continued)

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
292 DRIVING AND OPERATING
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 TurnsCaution
Making 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 0321.
Parking on Hills
{Warning
Parking 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.
2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, release the regular brakes
until the chocks absorb the load.

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 313
3.0L V6 Engine
1. Engine Coolant Surge Tankand Pressure Cap
2. Engine Cooling Fan (Out of View)
3.6L V6 Engine
1. Engine Coolant Surge Tank
and Pressure Cap
2. Engine Cooling Fan (Out of View)
{Warning
An underhood electric fan can start
up even when the engine is not
running and can cause injury. Keep
hands, clothing, and tools away
from any underhood electric fan. If the coolant inside the coolant surge
tank is boiling, do not do anything
else until it cools down. The vehicle
should be parked on a level surface.
The coolant level should be at the
cold fill mark on the middle of the
tank. If it is not, the vehicle may have
a leak at the radiator hoses, heater
hoses, radiator, water pump,
or somewhere else in the cooling
system.
{Warning
Do not touch heater or radiator
hoses, or other engine parts. They
can be very hot and can burn you.
Do not run the engine if there is a
leak; all coolant could leak out.
That could cause an engine fire and
can burn you. Fix any leak before
driving the vehicle.
If there seems to be no leak, with the
engine on, check to see if the electric
cooling fan is running. If the engine is
overheating, the fan should be
running. If it is not, the vehicle needs
service. Turn off the engine.

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 315
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
0 321.
The coolant surge tank is in the
engine compartment on the passenger
side of the vehicle. See Engine
Compartment Overview 0300.
How to Add Coolant to the
Coolant Surge Tank
If no problem is found, check to see if
coolant is visible in the coolant surge
tank. If coolant is visible but not at or above the indicated mark, add a 50/
50 mixture of clean, drinkable water
and DEX-COOL coolant. Be sure the
cooling system, including the coolant
surge tank pressure cap, is cool before
this is done. See
Engine Overheating
0 321.
{Warning
Spilling coolant on hot engine parts
can burn you. Coolant contains
ethylene glycol and it will burn if
the engine parts are hot enough.
{Warning
Steam and scalding liquids from a
hot cooling system are under
pressure. Turning the pressure cap,
even a little, can cause them to
come out at high speed and you
could be burned. Never turn the cap
when the cooling system, including
the pressure cap, is hot. Wait for
the cooling system and pressure
cap to cool.
Caution
Failure to follow the specific
coolant fill procedure could cause
the engine to overheat and could
cause system damage. If coolant is
not visible in the surge tank,
contact your dealer.
1. Remove the coolant surge tank
pressure cap when the cooling
system, including the coolant
surge tank pressure cap and
upper radiator hose, is no
longer hot.
Turn the pressure cap slowly
counterclockwise about
one-quarter of a turn. If you hear
a hiss, wait for that to stop. This
will allow any pressure still left
to be vented out the
discharge hose.

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.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/15/17
318 VEHICLE CARE
The coolant surge tank is in the
engine compartment on the passenger
side of the vehicle. SeeEngine
Compartment Overview 0300.
How to Add Coolant to the
Coolant Surge Tank
If no problem is found, check to see if
coolant is visible in the coolant surge
tank. If coolant is visible but not at or
above the indicated mark, add GM
Premix DEX-COOL coolant. Be sure
the cooling system, including the
coolant surge tank pressure cap, is
cool before this is done. See Engine
Overheating 0321.
{Warning
Spilling coolant on hot engine parts
can burn you. Coolant contains
ethylene glycol and it will burn if
the engine parts are hot enough.
{Warning
Steam and scalding liquids from a
hot cooling system are under
pressure. Turning the pressure cap,
even a little, can cause them to
come out at high speed and you
could be burned. Never turn the cap
when the cooling system, including
the pressure cap, is hot. Wait for
the cooling system and pressure
cap to cool.
Caution
Failure to follow the specific
coolant fill procedure could cause
the engine to overheat and could
cause system damage. If coolant is
not visible in the surge tank,
contact your dealer.
1. Remove the coolant surge tank
pressure cap when the cooling
system, including the coolant
surge tank pressure cap and
upper radiator hose, is no
longer hot.
Turn the pressure cap slowly
counterclockwise about
one-quarter of a turn. If you hear
a hiss, wait for that to stop. This
will allow any pressure still left
to be vented out the
discharge hose.
2. Keep turning the pressure cap slowly and remove it.
3. Fill the coolant surge tank with the proper mixture to the
indicated level mark.
4. With the coolant surge tank pressure cap off, start the engine
and let it run until you can feel

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/15/17
VEHICLE CARE 321
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.
SeeEngine Coolant Temperature Gauge
0 139 and Engine Coolant Temperature
Warning Light 0149. The vehicle may
also display a message on the Driver
Information Center (DIC).
If the decision is made not to lift the
hood when this warning appears, get
service help right away. See Roadside
Service 0411.
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
Do not run the engine if there is a
leak in the engine cooling system.
This can cause a loss of all coolant
and can damage the system and
vehicle. Have any leaks fixed
right away.
If Steam Is Coming from the
Engine Compartment
{Warning
Steam and scalding liquids from a
hot cooling system are under
pressure. Turning the pressure cap,
even a little, can cause them to
come out at high speed and you
could be burned. Never turn the cap
when the cooling system, including
the pressure cap, is hot. Wait for
the cooling system and pressure
cap to 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 too
serious. Sometimes the engine can get
a little too hot when the vehicle:
. Climbs a long hill on a hot day
. Stops after high-speed driving
. Idles for long periods in traffic
If the overheat warning is displayed
with no sign of steam: 1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature and to the highest
fan speed. Open the windows as
necessary.
3. When it is safe to do so, pull off the road, shift to P (Park) or
N (Neutral), and let the
engine idle.
If the engine coolant temperature
gauge is no longer in the overheated
area or the engine coolant
temperature warning light no longer
displays, the vehicle can be driven.
Continue to drive the vehicle slowly

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/15/17
VEHICLE CARE 325
Stop/Start System
The vehicle has a Stop/Start system to
shut off the engine to help conserve
fuel.
SeeStarting the Engine (PLUG-IN Only)
0 218 orStarting the Engine (Gasoline
Only) 0221.
{Warning
WARNING: Battery posts,
terminals, and related accessories
contain lead and lead compounds,
chemicals known to the State of
California to cause cancer and birth
defects or other reproductive harm.
Batteries also contain other
chemicals known to the State of
California to cause cancer. WASH
HANDS AFTER HANDLING. For
more information go to
www.P65Warnings.ca.gov/
passenger-vehicle.
See California Proposition 65 Warning
0 297 and the back cover.
PLUG-IN Vehicle
The PLUG-IN vehicle 12-volt battery is
in the trunk. PLUG-IN vehicles also
have a high voltage battery. Only a
trained service technician with the
proper knowledge and tools should
inspect, test, or replace the high
voltage battery. See your dealer if
either the 12-volt or the high voltage
battery needs service. The dealer has
information on how to recycle the
high voltage battery.
{Warning
Damage to the high voltage battery
or high voltage system can create a
risk of electric shock, overheating,
or fire.
If the vehicle is damaged from a
moderate to severe crash, flood,
fire, or other event, the vehicle
should be inspected as soon as
possible. Until the vehicle has been
inspected, store it outside at least
15 m (50 ft) from any structure or
(Continued)
Warning (Continued)
anything that can burn. Ventilate
the vehicle by opening a window or
a door.
Contact your dealer as soon as
possible to determine whether an
inspection is needed.
Vehicle Storage
{Warning
Batteries have acid that can burn
you and gas that can explode. You
can be badly hurt if you are not
careful. SeeJump Starting - North
America 0374 for tips on working
around a battery without
getting hurt.
Infrequent Usage: Remove the 12-volt
battery black, negative (−) cable from
the battery to keep the battery from
running down.