engine overheat CADILLAC CT6 2018 1.G Owners Manual

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
138 INSTRUMENTS AND CONTROLS
the normal operating range, check the
vehicle's oil as soon as possible. See
Engine Oil0307.
Caution
Lack of proper engine oil
maintenance can damage the
engine. Driving with the engine oil
low can also damage the engine.
The repairs would not be covered
by the vehicle warranty. Check the
oil level as soon as possible. Add oil
if required, but if the oil level is
within the operating range and the
oil pressure is still low, have the
vehicle serviced. Always follow the
maintenance schedule for changing
engine oil.
Engine Oil Temperature
Gauge (Performance
Configuration Only)
Metric
English
This gauge shows the engine oil
temperature.
If the gauge pointer moves into the
high end, it means that the engine oil
has overheated. If the vehicle has been
operated under normal driving
conditions, pull off the road, stop the
vehicle, and turn off the engine as
soon as possible.
See Engine Oil 0307.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
INSTRUMENTS AND CONTROLS 149
Engine Coolant
Temperature Warning Light
On some vehicles this light comes on
briefly while starting the vehicle. If it
does not, have the vehicle serviced by
the dealer. If the system is working
normally the indicator light goes off.
For vehicles with the reconfigurable
cluster, this light may not come on
when starting the vehicle.
Caution
The engine coolant temperature
warning light indicates that the
vehicle has overheated. Driving with
this light on can damage the engine
and it may not be covered by the
vehicle warranty. SeeEngine
Overheating 0321. The engine coolant temperature
warning light comes on when the
engine has overheated.
If this happens pull over and turn off
the engine as soon as possible. See
Engine Overheating
0321.
Tire Pressure Light
For vehicles with the Tire Pressure
Monitor System (TPMS), this light
comes on briefly when the engine is
started. It provides information about
tire pressures and the TPMS.
When the Light Is On Steady
This indicates that one or more of the
tires are significantly underinflated.
A Driver Information Center (DIC) tire
pressure message may also display.
Stop as soon as possible, and inflate the tires to the pressure value shown
on the Tire and Loading Information
label. See
Tire Pressure 0347.
When the Light Flashes First and
Then Is On Steady
If the light flashes for about a minute
and then stays on, there may be a
problem with the TPMS. If the
problem is not corrected, the light will
come on at every ignition cycle. See
Tire Pressure Monitor Operation 0350.
Engine Oil Pressure Light
Caution
Lack of proper engine oil
maintenance can damage the
engine. Driving with the engine oil
low can also damage the engine.
The repairs would not be covered
by the vehicle warranty. Check the
oil level as soon as possible. Add oil
if required, but if the oil level is
within the operating range and the
oil pressure is still low, have the
(Continued)

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
DRIVING AND OPERATING 211
.Have good tires with proper tread
depth. See Tires0340.
. Turn off cruise control.
Hill and Mountain Roads
Driving on steep hills or through
mountains is different than driving on
flat or rolling terrain. Tips include:
.Keep the vehicle serviced and in
good shape.
. Check all fluid levels and brakes,
tires, cooling system, and
transmission.
. Shift to a lower gear when going
down steep or long hills.
{Warning
Using the brakes to slow the vehicle
on a long downhill slope can cause
brake overheating, can reduce brake
performance, and could result in a
loss of braking. Shift the
transmission to a lower gear to let
the engine assist the brakes on a
steep downhill slope.
{Warning
Coasting downhill in N (Neutral) or
with the ignition off is dangerous.
This can cause overheating of the
brakes and loss of steering. Always
have the engine running and the
vehicle in gear.
. Drive at speeds that keep the
vehicle in its own lane. Do not
swing wide or cross the
center line.
. Be alert on top of hills; something
could be in your lane (e.g., stalled
car, accident).
. Pay attention to special road signs
(e.g., falling rocks area, winding
roads, long grades, passing or
no-passing zones) and take
appropriate action.
Winter Driving
Driving on Snow or Ice
Snow or ice between the tires and the
road creates less traction or grip, so
drive carefully. Wet ice can occur at
about 0 °C (32 °F) when freezing rain
begins to fall. Avoid driving on wet ice
or in freezing rain until roads can be
treated.
For slippery road driving:
.Accelerate gently. Accelerating too
quickly causes the wheels to spin
and makes the surface under the
tires slick.
. Turn on Traction Control. See
Traction Control/Electronic Stability
Control 0239.
. Antilock Brake System (ABS)
improves vehicle stability during
hard stops, but the brakes should
be applied sooner than when on
dry pavement. See Antilock Brake
System (ABS) 0234.
See Driver Mode Control (Gasoline
Only) 0241

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
DRIVING AND OPERATING 213
{Warning
If the vehicle's tires spin at high
speed, they can explode, and you or
others could be injured. The vehicle
can overheat, causing an engine
compartment fire or other damage.
Spin the wheels as little as possible
and avoid going above 56 km/h
(35 mph).
Rocking the Vehicle to Get it Out
Turn the steering wheel left and right
to clear the area around the front
wheels. Turn off any traction system.
Shift back and forth between
R (Reverse) and a low forward gear,
spinning the wheels as little as
possible. To prevent transmission
wear, wait until the wheels stop
spinning before shifting gears. Release
the accelerator pedal while shifting,
and press lightly on the accelerator
pedal when the transmission is in
gear. Slowly spinning the wheels in
the forward and reverse directions
causes a rocking motion that could
free the vehicle. If that does not get
the vehicle out after a few tries, itmight need to be towed out. If the
vehicle does need to be towed out, see
Towing the Vehicle
0376.
Vehicle Load Limits
It is very important to know how
much weight the vehicle can carry.
This weight is called the vehicle
capacity weight and includes the
weight of all occupants, cargo, and
all nonfactory-installed options.
Two labels on the vehicle may
show how much weight it may
properly carry: the Tire and
Loading Information label and the
Certification label.
{Warning
Do not load the vehicle any
heavier than the Gross Vehicle
Weight Rating (GVWR),
or either the maximum front or
rear Gross Axle Weight Rating
(GAWR). This can cause
systems to break and change
(Continued)
Warning (Continued)
the way the vehicle handles.
This could cause loss of control
and a crash. Overloading can
also reduce stopping distance,
damage the tires, and shorten
the life of the vehicle.
Tire and Loading Information
Label
Label Example
A vehicle-specific Tire and
Loading Information label is
attached to the vehicle's center

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
DRIVING AND OPERATING 219
Move the shift lever to P (Park) or
N (Neutral). To restart the engine
when the vehicle is already moving,
use N (Neutral) only.
Caution
Do not try to shift to P (Park) if the
vehicle is moving. If you do, you
could damage the transmission.
Shift to P (Park) only when the
vehicle is stopped.
Caution
If you add electrical parts or
accessories, you could change the
way the engine operates. Any
resulting damage would not be
covered by the vehicle warranty. See
Add-On Electrical Equipment0295.
PLUG-IN Starting Procedure 1. With the Keyless Access system, the Remote Keyless Entry (RKE)
transmitter must be in the
vehicle. Press ENGINE START/ STOP with the brake pedal
applied. When the engine begins
cranking, let go of the button.
The idle speed will go down as
the engine gets warm. Do not
race the engine immediately
after starting it.
If the RKE transmitter is not in
the vehicle, if there is
interference, or if the RKE
battery is low, a Driver
Information Center (DIC) will
display a message. See
Remote
Keyless Entry (RKE) System
Operation 035.Caution
Cranking the engine for long
periods of time, by returning the
ignition to the START position
immediately after cranking has
ended, can overheat and damage
the cranking motor, and drain the
battery. Wait at least 15 seconds
between each try, to let the
cranking motor cool down. 2. If the engine does not start after
five to 10 seconds, especially in
very cold weather (below −18 °C
or 0 °F), it could be flooded with
too much gasoline. Try pushing
the accelerator pedal all the way
to the floor and holding it there
as you press ENGINE START/
STOP. Wait at least 15 seconds
between each try, to allow the
cranking motor to cool down.
When the engine starts, release
the accelerator. If the vehicle
starts briefly but then stops
again, do the same thing. This
clears the extra gasoline from the
engine. Do not race the engine
immediately after starting it.
Operate the engine and
transmission gently until the oil
warms up and lubricates all
moving parts.
When the state of charge is low and
the hood is open, the vehicle may not
start. Close the hood and follow the
starting procedure again.
The vehicle will emit an audible
startup beep when the vehicle is ready
to be driven. When the vehicle ready
light is on in the instrument cluster,

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
DRIVING AND OPERATING 221
SeeAutomatic Climate Control
System (Quad Zone - Gasoline Only)
0 197 orAutomatic Climate Control
System (Dual Zone - Gasoline and
PLUG-IN) 0191.
. The Auto Stop time is greater than
two minutes.
. With the hood open, the engine
will be in an Auto Stop. The driver
may force the engine on when the
hood is open, by completely
pressing the accelerator pedal for
at least two seconds.
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.
Starting the Engine
(Gasoline Only)
Move the shift lever to P (Park) or
N (Neutral). To restart the engine
when the vehicle is already moving,
use N (Neutral) only.
Caution
Do not try to shift to P (Park) if the
vehicle is moving. If you do, you
could damage the transmission.
Shift to P (Park) only when the
vehicle is stopped.
Caution
If you add electrical parts or
accessories, you could change the
way the engine operates. Any
resulting damage would not be
covered by the vehicle warranty. See
Add-On Electrical Equipment 0295.
Starting Procedure 1. With the Keyless Access system, the Remote Keyless Entry (RKE)
transmitter must be in the
vehicle. Press ENGINE START/
STOP with the brake pedal
applied. When the engine begins
cranking, let go of the button. The idle speed will go down as
the engine gets warm. Do not
race the engine immediately
after starting it.
If the RKE transmitter is not in
the vehicle, if there is
interference, or if the RKE
battery is low, a Driver
Information Center (DIC) will
display a message. See
Remote
Keyless Entry (RKE) System
Operation 035.
Caution
Cranking the engine for long
periods of time, by returning the
ignition to the START position
immediately after cranking has
ended, can overheat and damage
the cranking motor, and drain the
battery. Wait at least 15 seconds
between each try, to let the
cranking motor cool down.
2. If the engine does not start after five to 10 seconds, especially in
very cold weather (below −18 °C
or 0 °F), it could be flooded with

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
224 DRIVING AND OPERATING
Warning (Continued)
overheat and cause a fire,
property damage, electric
shock, and injury.
. Do not operate the vehicle
with the heater cord
permanently attached to the
vehicle. Possible heater cord
and thermostat damage could
occur.
. While in use, do not let the
heater cord touch vehicle
parts or sharp edges. Never
close the hood on the
heater cord.
. Before starting the vehicle,
unplug the cord, reattach the
cover to the plug, and
securely fasten the cord. Keep
the cord away from any
moving parts.
4. Before starting the engine, be sure to unplug and store the cord
as it was before to keep it away
from moving engine parts. If you
do not, it could be damaged. Contact your dealer for information
on how long to use the heater in your
particular area.
Retained Accessory
Power (RAP)
Some vehicle accessories may be used
after the ignition is turned off.
The power windows and sunroof,
if equipped, will continue to work for
up to 10 minutes or until any door is
opened.
The infotainment system will continue
to work for 10 minutes, until the
driver door is opened, or until the
ignition is turned on or placed in
ACC/ACCESSORY.
Shifting Into Park
To shift into P (Park):
1. Hold the brake pedal down and set the parking brake.
See Electric Parking Brake 0235. 2. Move the shift lever into P (Park)
by holding in the button on the
shift lever and pushing the lever
all the way toward the front of
the vehicle.
3. Turn the ignition off.
4. Take the Remote Keyless Entry (RKE) transmitter with you.
Leaving the Vehicle with the
Engine Running
{Warning
It can be dangerous to leave the
vehicle with the engine running.
It could overheat and catch fire.
It is dangerous to get out of the
vehicle if the shift lever is not fully
in P (Park) with the parking brake
firmly set. The vehicle can roll.
Do not leave the vehicle when the
engine is running. If you have left
the engine running, the vehicle can
move suddenly. You or others could
be injured. To be sure the vehicle
will not move, even when you are
(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