2016 CADILLAC CT6 engine overheat

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
Vehicle Care 279
{ WarningSteam 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.
{ 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
overheat warning. The engine
could catch fire and you or others
(Continued) Warning (Continued) could be burned. Use a 50/
50 mixture of clean, drinkable
water and DEX-COOL coolant.
CautionIn 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
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 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.

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 281too 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 0 265 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.
(Continued)

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/6/15
388 Index E Electric Parking Brake . . . . . . . . . . 214
Electric Parking Brake Light . . . . 134
Electrical Equipment,
Add-On . . . . . . . . . . . . . . . . . . . . . . . 260
Electrical System
Engine Compartment Fuse
Block . . . . . . . . . . . . . . . . . . . . . . . . 290
Fuses and Circuit Breakers . . . 290
Instrument Panel Fuse
Block . . . . . . . . . . . . . . . . . . . . . . . . 293
Overload . . . . . . . . . . . . . . . . . . . . . 289
Rear Compartment Fuse
Block . . . . . . . . . . . . . . . . . . . . . . . . 295
Emergency
OnStar ®
. . . . . . . . . . . . . . . . . . . . . . 376
Engine
Air Cleaner/Filter . . . . . . . . . . . . . 273
Check and Service Engine
Soon Light . . . . . . . . . . . . . . . . . . 132
Compartment Overview . . . . . . . 265
Coolant . . . . . . . . . . . . . . . . . . . . . . . 277
Coolant Heater . . . . . . . . . . . . . . . 206
Coolant Temperature
Gauge . . . . . . . . . . . . . . . . . . . . . . 128 Engine (cont'd)
Coolant Temperature
Warning Light . . . . . . . . . . . . . . . 137
Cooling System . . . . . . . . . . . . . . . 275
Cooling System Messages . . . 149
Drive Belt Routing . . . . . . . . . . . . 360
Exhaust . . . . . . . . . . . . . . . . . . . . . . 209
Oil Life System . . . . . . . . . . . . . . . 272
Oil Messages . . . . . . . . . . . . . . . . . 149
Oil Pressure Gauge . . . . . . . . . . 126
Oil Pressure Light . . . . . . . . . . . . 138
Overheating . . . . . . . . . . . . . . . . . . 280
Power Messages . . . . . . . . . . . . . 150
Running While Parked . . . . . . . . 210
Starting . . . . . . . . . . . . . . . . . . . . . . . 204
Engine Oil
Temperature Gauge . . . . . . . . . . 127
Entry Lighting . . . . . . . . . . . . . . . . . . . 175
Equipment, Towing . . . . . . . . . . . . . 259
Event Data Recorders . . . . . . . . . . 373
Exit Lighting . . . . . . . . . . . . . . . . . . . . 176
Extender, Safety Belt . . . . . . . . . . . . 75
Exterior Lamp Controls . . . . . . . . . 170
Exterior Lamps Off Reminder . . . 172
Exterior Lighting Battery
Saver . . . . . . . . . . . . . . . . . . . . . . . . . 176 F Features
Memory . . . . . . . . . . . . . . . . . . . . . . . . . 12
Filter,
Engine Air Cleaner . . . . . . . . . . . 273
Flash-to-Pass . . . . . . . . . . . . . . . . . . . 172
Flashers, Hazard Warning . . . . . . 173
Flat Tire . . . . . . . . . . . . . . . . . . . . . . . . 320
Changing . . . . . . . . . . . . . . . . . . . . . 321
Floor Mats . . . . . . . . . . . . . . . . . . . . . . 341
Fluid
Automatic Transmission . . . . . . 273
Brakes . . . . . . . . . . . . . . . . . . . . . . . . 283
Washer . . . . . . . . . . . . . . . . . . . . . . . 281
Forward Collision Alert
(FCA) System . . . . . . . . . . . . . . . . . 237
Frequency Statement
Radio . . . . . . . . . . . . . . . . . . . . . . . . . 371
Front Automatic Braking
(FAB) System . . . . . . . . . . . . . . . . . 240
Front Pedestrian Braking
(FPB) System . . . . . . . . . . . . . . . . . 241
Front Seats
Heated and Ventilated . . . . . . . . . . 64
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
Additives . . . . . . . . . . . . . . . . . . . . . 253
Economy Driving . . . . . . . . . . . . . . . 27