2021 CADILLAC CT5 engine overheat

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
DRIVING AND OPERATING 229
Retained Accessory
Power (RAP)
When the ignition is turned from on
to off, the following features (if
equipped) will continue to function
for up to 10 minutes, or until the
driver door is opened. These features
will also work when the ignition is in
RUN or ACC/ACCESSORY:
.Infotainment System
.Power Windows (during RAP this
functionality will be lost when any
door is opened)
.Sunroof (during RAP this
functionality will be lost when any
door is opened)
.Auxiliary Power Outlet
.Audio System
.OnStar System
Shifting Into Park
To shift into P (Park):1. Hold the brake pedal down and set the parking brake. See Electric
Parking Brake 0238. 2. Press the button on top of the shift
lever to shift into P (Park). See
Automatic Transmission 0231.
3. The P indicator on the shift lever will turn red when the vehicle is in
P (Park).
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 vehicle is not in
P (Park) with the parking brake 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
(Continued)
Warning (Continued)
shift to P (Park). SeeShifting Into
Park 0229. If you are towing a
trailer, see Driving Characteristics
and Towing Tips 0301.
If you have to leave the vehicle with
the engine running, be sure the
vehicle is in P (Park) and the parking
brake is set before you leave it.
If you are towing a trailer and parking
on a hill, see Driving Characteristics
and Towing Tips 0301.
Shifting out of Park
This vehicle is equipped with an
electronic transmission. The shift lock
release button is designed to prevent
inadvertent shifting out of P (Park).
To shift out of P (Park):
1. Ensure the engine is running.
2. Apply the brake pedal.
3. Press and hold the shift lock release button on the shift lever.

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
DRIVING AND OPERATING 303
necessary to go much farther beyond
the passed vehicle before returning to
the lane. Pass on level roadways.
Avoid passing on hills if possible.
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
that hand to the right. Always back up
slowly and, if possible, have someone
guide you.
Making TurnsCaution
Turn more slowly and make wider
arcs when towing a trailer to
prevent damage to your vehicle.
Making very sharp turns could
cause the trailer to contact the
vehicle.
Make wider turns than normal when
towing, so trailer will not go over soft
shoulders, over curbs, or strike road
signs, trees, or other objects. Always
signal turns well in advance. Do not
steer or brake suddenly.
Driving on Grades
Reduce speed and shift to a lower gear
before starting down a long or steep
downhill grade. If the transmission is
not shifted down, the brakes may
overheat and result in reduced braking
efficiency.
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 higher altitudes,
engine coolant will boil at a lower
temperature than at lower altitudes.
If the engine is turned off immediately
after towing at high altitude on steep
uphill grades, the vehicle could show
signs similar to engine overheating. To
avoid this, let the engine run,
preferably on level ground, with the
transmission in P (Park) for a few
minutes before turning the engine off.
If the overheat warning comes on, see
Engine Overheating 0326.
Parking on Hills
{Warning
To prevent serious injury or death,
always park your vehicle and trailer
on a level surface when possible.
When parking your vehicle and your
trailer 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, gradually release the brake
pedal to allow the chocks to absorb
the load of the trailer.
4. Reapply the brake pedal. Then apply the parking brake and shift
into P (Park).
5. Release the brake pedal.
Leaving After Parking on a Hill
1. Apply and hold the brake pedal.
.Start the engine.

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
304 DRIVING AND OPERATING
.Shift into a gear.
.Release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
Maintenance when Trailer
Towing
The vehicle needs service more often
when used to tow trailers. See
Maintenance Schedule 0383. It is
especially important to check the
automatic transmission fluid, engine
oil, axle lubricant, belts, cooling
system, and brake system before and
during each trip.
Check periodically that all nuts and
bolts on the trailer hitch are tight.
Engine Cooling when Trailer
Towing
The cooling system may temporarily
overheat during severe operating
conditions. See Engine Overheating
0 326.
Trailer Towing (LSY 2.0L
L4 and LGY 3.0L
V6 Engines Only)
Caution
Towing a trailer improperly can
damage the vehicle and result in
costly repairs not covered by the
vehicle warranty. To tow a trailer
correctly, follow the directions in
this section and see your dealer for
important information about
towing a trailer with the vehicle.
Trailer Weight
{Warning
Never exceed the towing capacity
for your vehicle.
Safe trailering requires monitoring the
weight, speed, altitude, road grades,
outside temperature, dimensions of
the front of the trailer, and how
frequently the vehicle is used to tow a
trailer.
Before towing a trailer, always
separately weigh:
.the total weight on the vehicle's
tires.
.the trailer.
.the trailer tongue.
{Warning
You and others could be seriously
injured or killed if the trailer is too
heavy or the trailer brakes are
inadequate for the load. The vehicle
may be damaged, and the repairs
would not be covered by the vehicle
warranty.
Only tow a trailer if all the steps in
this section have been followed. Ask
your dealer for advice and
information about towing a trailer.
Gross Vehicle Weight
Rating (GVWR)
For information about the vehicle's
maximum load capacity, see Vehicle
Load Limits 0219. When calculating
the GVWR with a trailer attached, the
trailer tongue weight must be
included as part of the weight the
vehicle is carrying.

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
308 VEHICLE CARE
Vehicle Care
General Information
General Information . . . . . . . . . . . . . 309
California Proposition65 Warning . . . . . . . . . . . . . . . . . . . . . 309
California Perchlorate Materials Requirements . . . . . . . . . . . . . . . . . . . 309
Accessories and Modifications . . . . . . . . . . . . . . . . . . . 310
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . . . . . . 310
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . . . . . . 313
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . 316
Engine Oil Life System . . . . . . . . . . . 318
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319
Engine Air Filter Life System . . . . 319
Engine Air Cleaner/Filter . . . . . . . . . 320
Cooling System . . . . . . . . . . . . . . . . . . . 322
Engine Overheating . . . . . . . . . . . . . . 326
Washer Fluid . . . . . . . . . . . . . . . . . . . . . 327
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328
Brake Pad Life System (If Equipped) . . . . . . . . . . . . . . . . . . . . . . . 328
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . 329 Battery - North America . . . . . . . . . 330
All-Wheel Drive . . . . . . . . . . . . . . . . . . 331
Park Brake and P (Park)
Mechanism Check . . . . . . . . . . . . . . 331
Wiper Blade Replacement . . . . . . . 331
Windshield Replacement . . . . . . . . 332
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . 332
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . 333
Bulb Replacement
LED Lighting . . . . . . . . . . . . . . . . . . . . . 334
Electrical System
Electrical System Overload . . . . . . 334
Fuses and Circuit Breakers . . . . . . 334
Engine Compartment Fuse
Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335
Instrument Panel Fuse Block . . . . 337
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 342
All-Season Tires . . . . . . . . . . . . . . . . . . 342
Winter Tires . . . . . . . . . . . . . . . . . . . . . . 343
Run-Flat Tires . . . . . . . . . . . . . . . . . . . . 343
Self-Sealing Tires . . . . . . . . . . . . . . . . . 344
Low-Profile Tires . . . . . . . . . . . . . . . . . 344
Summer Tires . . . . . . . . . . . . . . . . . . . . 344
Tire Sidewall Labeling . . . . . . . . . . . 345 Tire Designations . . . . . . . . . . . . . . . . . 346
Tire Terminology and
Definitions . . . . . . . . . . . . . . . . . . . . . . 347
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . 349
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . . . . . . 350
Tire Pressure Monitor System . . . 351
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . . . . . . 352
Tire Inspection . . . . . . . . . . . . . . . . . . . 355
Tire Rotation . . . . . . . . . . . . . . . . . . . . . 355
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 356
Buying New Tires . . . . . . . . . . . . . . . . 357
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . . . . . 358
Uniform Tire Quality Grading . . . 359
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . . . . . . 360
Wheel Replacement . . . . . . . . . . . . . . 360
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . 361
If a Tire Goes Flat . . . . . . . . . . . . . . . . 361
Tire Sealant and Compressor Kit . . . . . . . . . . . . . . . . . 362
Storing the Tire Sealant and Compressor Kit . . . . . . . . . . . . . . . . . 368
Jump Starting
Jump Starting - NorthAmerica . . . . . . . . . . . . . . . . . . . . . . . . . 368

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
VEHICLE CARE 323
{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.
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.
Engine Coolant
The cooling system in the vehicle is
filled with DEX-COOL engine coolant.
SeeMaintenance Schedule 0383 and
Recommended Fluids and Lubricants
0 392. 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
0326.
What to Use
{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.
Use a 50/50 mixture of clean
drinkable water and DEX-COOL
coolant. 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.
It is normal to see coolant moving in
the upper coolant hose return line
when the engine is running. It is also
normal to see bubbles entering the
surge tank through the small hose.

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
324 VEHICLE CARE
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 is 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 is cool
before this is done.
If no coolant is visible in the coolant
surge tank, add coolant as follows:
How to Add Coolant to the
Coolant Surge Tank
{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
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.
{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(Continued)
Warning (Continued)
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.
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 or above the
indicated mark, add a 50/50 mixture
of 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.

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
326 VEHICLE CARE
3. Fill the surge tank with the propermixture 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
surge tank until the level reaches
the indicated level mark.
5. Replace the pressure cap tightly. 6. Check the level in the surge tank
after the engine is shut off and the
cooling system has cooled down.
If the coolant is not at the proper
level, repeat 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 engine
damage may occur. Be sure the cap
is properly and tightly secured.
Engine Overheating
The vehicle has an indicator to warn
of the engine overheating.
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 CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
VEHICLE CARE 327
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 overheat warning no longer
displays, the vehicle can be driven.
Continue to drive the vehicle slowly
for about 10 minutes. Keep a safe
vehicle 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 0313 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 to freeze
and damage the washer fluid
tank and other parts of the
washer system.
.When using concentrated washer
fluid, follow the manufacturer
instructions for adding water.
.Fill the washer fluid tank only
three-quarters full when it is very
cold. This allows for fluid
(Continued)