2019 CADILLAC CT6 overheating

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
308 VEHICLE CARE
3.6L V6 Engine
1. Engine Coolant Surge Tankand Pressure Cap (Under
Cover)
2. Engine Cooling Fan (Out of View)
4.2L V8 Engine
1. Engine Coolant Surge Tankand Pressure Cap (Under
Cover)
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-12533370) -
2019 - crc - 1/23/19
VEHICLE CARE 309
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 0383.
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 0312.
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
temperature.Caution
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
engine cooling system 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.
3.0L V6 Engine Coolant Surge Tank

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
310 VEHICLE CARE
2.0L L4, 3.6L V6, and 4.2L V8 EngineCoolant Surge Tank
The coolant surge tank is in the
engine compartment on the passenger
side of the vehicle. See Engine
Compartment Overview 0292.
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
0 312.
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 0312.
{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
(Continued)
Warning (Continued)
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.
3.0L V6 and 3.6L V6 Engines

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
312 VEHICLE CARE
At the end of the cycle, check the
coolant level in the surge tank and
add coolant if it is low. Turn off the
vehicle, allow the Electronic Control
Module (ECM) to go to sleep, about
2 minutes, and repeat Steps 4-7.
Listen for pump activation and
movement of the control valves while
watching the level of the coolant in
the surge tank. If the tank empties,
turn the ignition off, carefully remove
the surge tank cap, refill to the COLD
FILL mark, and repeat Steps 4-7. The
fill and air removal process will run
for approximately 10 minutes.
4.2L V8 Engine OnlyCaution
This vehicle has a specific coolant
fill procedure. Failure to follow this
procedure could cause the engine to
overheat and be severely damaged.
See your dealer for assistance.
Because of possible engine failure or
damage if performed without the
proper tools and information, engine coolant should only be added
by a qualified technician. See your
dealer.
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 0135 and
Engine Coolant Temperature Warning
Light 0146. 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 0405.
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.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
322 VEHICLE CARE
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 wiperlinkage damage. Always clear ice and
heavy snow from the windshield
before using the windshield wipers.
If the overload is caused by an
electrical problem and not snow or
ice, be sure to get it fixed.
Fuses and Circuit Breakers
The wiring circuits in the vehicle are
protected from short circuits by a
combination of fuses and circuit
breakers. This greatly reduces the
chance of damage caused by electrical
problems.
{Danger
Fuses and circuit breakers are
marked with their ampere rating.
Do not exceed the
specified amperage rating when
replacing fuses and circuit breakers.
Use of an oversized fuse or circuit
breaker can result in a vehicle fire.
You and others could be seriously
injured or killed.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
VEHICLE CARE 339
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 Limits0197.
(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 0347 for inflation
pressure adjustment for
high-speed driving.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
346 VEHICLE CARE
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 0354.
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 0357. Vehicle Capacity Weight
:The
number of designated seating
positions multiplied by
68 kg (150 lb) plus the rated cargo
load. See Vehicle Load Limits 0197.
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 0197.
Tire Pressure
Tires need the correct amount of
air pressure to operate effectively.
{Warning
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.
.Poor handling.
.Rough ride.
.Needless damage from
road hazards.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
INDEX 429
Driving (cont'd)Vehicle Load Limits . . . . . . . . . . . . . . 197
Wet Roads . . . . . . . . . . . . . . . . . . . . . . . . . 193
Winter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
E
Electric Parking Brake . . . . . . . . . . . . . . 218
Electric Parking Brake Light . . . . . . . 143
Electrical Equipment, Add-On . . . . . 287
Electrical System
Engine Compartment FuseBlock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
Fuses and Circuit Breakers . . . . . . . 322
Instrument Panel Fuse Block . . . . 330
Overload . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
Emergency OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415
Engine Air Cleaner/Filter . . . . . . . . . . . . . . . . . 304
Check Light (MalfunctionIndicator) . . . . . . . . . . . . . . . . . . . . . . . . 139
Compartment Overview . . . . . . . . . . 292
Coolant Temperature Gauge . . . . . 135
Coolant Temperature
Warning Light . . . . . . . . . . . . . . . . . . . 146
Cooling System . . . . . . . . . . . . . . . . . . . 307 Engine (cont'd)
Drive Belt Routing . . . . . . . . . . . . . . . . 399
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
Oil Life System . . . . . . . . . . . . . . . . . . . . 302
Oil Pressure Gauge . . . . . . . . . . . . . . . . 134
Oil Pressure Light . . . . . . . . . . . . . . . . . 147
Overheating . . . . . . . . . . . . . . . . . . . . . . . 312
Power Messages . . . . . . . . . . . . . . . . . . 156
Running While Parked . . . . . . . . . . . 210
Starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202
Engine Air Filter Life System . . . . . . 304
Entry Lighting . . . . . . . . . . . . . . . . . . . . . . 172
Equipment, Towing . . . . . . . . . . . . . . . . . 286
Event Data Recorders . . . . . . . . . . . . . . 412
Exit Lighting . . . . . . . . . . . . . . . . . . . . . . . . 172
Extended Parking . . . . . . . . . . . . . . . . . . . 209
Extender, Seat Belt . . . . . . . . . . . . . . . . . . 82
Exterior Lamp Controls . . . . . . . . . . . . 166
Exterior Lamps Off Reminder . . . . . . 168
Exterior Lighting Battery Saver . . . . 173
F
Features Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Filter, Engine Air Cleaner . . . . . . . . . . . . . . . . 304 Flash-to-Pass . . . . . . . . . . . . . . . . . . . . . . . . 168
Flashers, Hazard Warning . . . . . . . . . . 169
Flat Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359
Changing . . . . . . . . . . . . . . . . . . . . . . . . . . 361
Floor Mats . . . . . . . . . . . . . . . . . . . . . . . . . . . 379
Fluid Automatic Transmission . . . . . . . . . 303
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315
Washer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313
Folding Mirrors . . . . . . . . . . . . . . . . . . . . . . 53
Forward Automatic Braking . . . . . . . . 264
Forward Collision Alert (FCA) System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
Frequency Statement Radio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 411
Front Pedestrian Braking (FPB)
System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
Front Seats Heated and Ventilated . . . . . . . . . . . . . 70
Fuel Additives . . . . . . . . . . . . . . . . . . . . . . . . . . 278
Economy Driving . . . . . . . . . . . . . . . . . . . 27
Filling a Portable Fuel
Container . . . . . . . . . . . . . . . . . . . . . . . . 280
Filling the Tank . . . . . . . . . . . . . . . . . . . 278
Foreign Countries . . . . . . . . . . . . . . . . . 278
Gauge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
Low Fuel Warning Light . . . . . . . . . 148