2017 CADILLAC CT6 engine overheat

Cadillac CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
CRC - 6/21/16
DRIVING AND OPERATING 199
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
on fairly level ground, always set
the parking brake and move the
shift lever to P (Park). SeeShifting
Into Park 0198.
If you have to leave the vehicle with
the engine running, the vehicle must
be in P (Park) and the parking brake set. After shifting into P (Park), try to
move the shift lever out without first
pushing the button on the shift lever.
If you can, the shift lever was not
fully locked into P (Park).Torque Lock
Torque lock is when the weight of the
vehicle puts too much force on the
parking pawl in the transmission. This
happens when parking on a hill and
shifting the transmission into P (Park)
is not done properly and then it is
difficult to shift out of P (Park). To
prevent torque lock, set the parking
brake and then shift into P (Park). To
find out how, see "Shifting Into Park"
listed previously.
If torque lock does occur, the vehicle
may need to be pushed uphill by
another vehicle to relieve the parking
pawl pressure, so you can shift out of
P (Park).
Shifting out of Park
This vehicle is equipped with an
electronic shift lock release system.
The shift lock release is designed to
prevent movement of the shift leverout of P (Park), unless the ignition is
in ON/RUN and the brake pedal is
applied.
The shift lock release is always
functional except in the case of an
uncharged or low voltage (less than
9 volt) battery.
If the vehicle has an uncharged
battery or a battery with low voltage,
try charging or jump starting the
battery. See
Jump Starting 0296 for
more information.
To shift out of P (Park):
1. Apply the brake pedal.
2. Release the parking brake. See Electric Parking Brake 0205.
3. Press the shift lever button.
4. Move the shift lever.
If unable to shift out of P (Park): 1. Fully release the shift lever button.
2. While holding down the brake pedal, press the shift lever
button again.
3. Move the shift lever.

Cadillac CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
CRC - 6/21/16
DRIVING AND OPERATING 207
Caution
Driving with the parking brake on
can overheat the brake system and
cause premature wear or damage to
brake system parts. Make sure that
the parking brake is fully released
and the brake warning light is off
before driving.
Automatic EPB Release
The EPB will automatically release if
the vehicle is running, placed into
gear, and an attempt is made to drive
away. Avoid rapid acceleration when
the EPB is applied, to preserve parking
brake lining life.
Brake Assist
This vehicle has a brake assist feature
designed to assist the driver in
stopping or decreasing vehicle speed
in emergency driving conditions. This
feature uses the stability system
hydraulic brake control module to
supplement the power brake system
under conditions where the driver has
quickly and forcefully applied thebrake pedal in an attempt to quickly
stop or slow down the vehicle. The
stability system hydraulic brake
control module increases brake
pressure at each corner of the vehicle
until the ABS activates. Minor brake
pedal pulsation or pedal movement
during this time is normal and the
driver should continue to apply the
brake pedal as the driving situation
dictates. The brake assist feature will
automatically disengage when the
brake pedal is released or brake pedal
pressure is quickly decreased.
Hill Start Assist (HSA)
Hill Start Assist (HSA) may
automatically activate when the
vehicle is stopped on a hill and
Automatic Vehicle Hold (AVH) is not
enabled. This feature is designed to
prevent the vehicle from rolling, either
forward or rearward, during vehicle
drive off. During the transition from
releasing the brake pedal to
accelerating to drive off on a hill, HSA
holds the braking pressure to prevent
rolling. HSA will not activate if the
vehicle is in a drive gear and facing
downhill or if the vehicle is facing
uphill and in R (Reverse).
Automatic Vehicle
Hold (AVH)
Automatic Vehicle Hold (AVH) can be
turned on by pressing AUTO HOLD
with the driver safety belt fastened,
the driver door closed, and the engine
running. The AVH indicator will
come on.
This feature will activate when the
vehicle is stopped to prevent it from
moving. After the brake pedal has
been released and before the

Cadillac CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
CRC - 6/21/16
244 VEHICLE CARE
Vehicle Care
General Information
General Information . . . . . . . . . . . . . 245
Accessories andModifications . . . . . . . . . . . . . . . . . . . 245
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . . . . . . 245
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . . . . . . 247
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . 250
Engine Oil Life System . . . . . . . . . . . 252
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253
Engine Air Cleaner/Filter . . . . . . . . . 254
Cooling System . . . . . . . . . . . . . . . . . . . 255
Engine Coolant . . . . . . . . . . . . . . . . . . . 256
Engine Overheating . . . . . . . . . . . . . . 259
Washer Fluid . . . . . . . . . . . . . . . . . . . . . 260
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . 262
Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
All-Wheel Drive . . . . . . . . . . . . . . . . . . 264
Starter Switch Check . . . . . . . . . . . . . 264
Automatic Transmission Shift Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264 Park Brake and P (Park)
Mechanism Check . . . . . . . . . . . . . . 265
Wiper Blade Replacement . . . . . . . 265
Windshield Replacement . . . . . . . . 266
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . . . . . 266
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . 267
LED Lighting . . . . . . . . . . . . . . . . . . . . . 267
License Plate Lamp . . . . . . . . . . . . . . 267
Replacement Bulbs . . . . . . . . . . . . . . . 267
Electrical System
Electrical System Overload . . . . . . 268
Fuses and Circuit Breakers . . . . . . 269
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269
Instrument Panel Fuse Block . . . . 272
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
All-Season Tires . . . . . . . . . . . . . . . . . . 277
Winter Tires . . . . . . . . . . . . . . . . . . . . . . 277
Low-Profile Tires . . . . . . . . . . . . . . . . . 278
Summer Tires . . . . . . . . . . . . . . . . . . . . 278
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . 279
Tire Pressure for High-SpeedOperation . . . . . . . . . . . . . . . . . . . . . . . . 280 Tire Pressure Monitor System . . . 280
Tire Pressure Monitor
Operation . . . . . . . . . . . . . . . . . . . . . . . . 281
Tire Inspection . . . . . . . . . . . . . . . . . . . 284
Tire Rotation . . . . . . . . . . . . . . . . . . . . . 284
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286
Buying New Tires . . . . . . . . . . . . . . . . 286
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . . . . . 288
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . . . . . . 288
Wheel Replacement . . . . . . . . . . . . . . 288
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . 289
If a Tire Goes Flat . . . . . . . . . . . . . . . . 289
Tire Changing . . . . . . . . . . . . . . . . . . . . . 291
Compact Spare Tire . . . . . . . . . . . . . . 295
Jump Starting
Jump Starting . . . . . . . . . . . . . . . . . . . . . 296
Towing the Vehicle
Towing the Vehicle . . . . . . . . . . . . . . . 299
Recreational Vehicle Towing . . . . 299
Appearance Care
Exterior Care . . . . . . . . . . . . . . . . . . . . . . 301
Interior Care . . . . . . . . . . . . . . . . . . . . . . 305
Floor Mats . . . . . . . . . . . . . . . . . . . . . . . . 308

Cadillac CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
CRC - 6/21/16
256 VEHICLE CARE
{Warning
Heater and radiator hoses, and
other engine parts, can be very hot.
Do not touch them. If you do, you
can be burned.
Do not run the engine if there is a
leak. If you run the engine, it could
lose all coolant. That could cause
an engine fire, and you could be
burned. Get any leak fixed before
you drive the vehicle.
Caution
Using coolant other than
DEX-COOL®can cause premature
engine, heater core, or radiator
corrosion. In addition, the engine
coolant could require changing
sooner. Any repairs would not be
covered by the vehicle warranty.
Always use DEX-COOL (silicate-free)
coolant in the vehicle.
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 0311.
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 0259.
What to Use
{Warning
Adding 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 overheat
warning. The engine could catch
(Continued)
Warning (Continued)
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.

Cadillac CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
CRC - 6/21/16
VEHICLE CARE 257
Caution
If 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. SeeRecommended Fluids
and Lubricants 0318.
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.
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. 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 is cool
before this is done. See
Engine
Overheating 0259.
The coolant surge tank is in the
engine compartment on the passenger
side of the vehicle. See Engine
Compartment Overview 0247.
How to Add Coolant to the
Coolant Surge Tank
Caution
This 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 is not at the indicated
level mark, add a 50/50 mixture of

Cadillac CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
CRC - 6/21/16
258 VEHICLE CARE
clean, drinkable water and DEX-COOL
coolant at the coolant surge tank, but
be sure the cooling system, including
the coolant surge tank pressure cap, is
cool before you do it.
{Warning
Steam and scalding liquids from a
hot cooling system can blow out
and burn you badly. Never turn the
cap when the cooling system,
including the surge tank pressure
cap, is hot. Wait for the cooling
system and surge tank pressure cap
to cool.
{Warning
Adding 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(Continued)
Warning (Continued)
plain water or the wrong mixture,
the engine could get too hot but
you would not get the 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.
Caution
In cold weather, water can freeze
and crack the engine, radiator,
heater core, and other parts. Use
the recommended coolant and the
proper coolant mixture.
{Warning
You can be burned if you spill
coolant on hot engine parts.
Coolant contains ethylene glycol(Continued)
Warning (Continued)
and it will burn if the engine parts
are hot enough. Do not spill coolant
on a hot engine.
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-MidEast-10293390) - 2017 -
CRC - 6/21/16
VEHICLE CARE 259
the upper radiator hose getting
hot. Watch out for the engine
cooling fan.
By this time, the coolant level
inside the coolant surge tank
may be lower. If the level is
lower, add more of the proper
mixture to the coolant surge
tank until the level reaches the
indicated level mark.
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.
Caution
If 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 0124 and
Engine Coolant Temperature Warning
Light 0132. The vehicle may also
display a message on the Driver
Information Center (DIC). See Engine
Cooling System Messages 0143.
If the decision is made not to lift the
hood when this warning appears, get
service help right away.
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
{Warning
Steam 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.

Cadillac CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
CRC - 6/21/16
260 VEHICLE CARE
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 for about 10 minutes. Keep a safe
distance from the vehicle in front.
If the warning does not come back on,
continue to drive normally and have
the cooling system checked for proper
fill and function.
If the warning continues, pull over,
stop, and park the vehicle right away.
If there is no sign of steam, idle the
engine for three minutes while parked.
If the warning is still displayed, turn
off the engine until it cools down.
Washer Fluid
What to Use
When windshield washer fluid is
needed, be sure to read the
manufacturer's instructions before
use. If operating the vehicle in an area
where the temperature may fall below
freezing, use a fluid that has sufficient
protection against freezing.
Adding Washer Fluid
Open the cap with the washer symbol
on it. Add washer fluid until the tank
is full. See
Engine Compartment
Overview 0247 for reservoir location.
Caution
.
Do not use washer fluid that
contains any type of water
repellent coating. This can
cause the wiper blades to
chatter or skip.
. Do not use engine coolant
(antifreeze) in the windshield
washer. It can damage the
windshield washer system
and paint.
. Do not mix water with
ready-to-use washer fluid.
Water can cause the solution
(Continued)