2021 CADILLAC CT5 warning

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
318 VEHICLE CARE
Engine Oil Additives/Engine Oil
Flushes
Do not add anything to the oil. The
recommended oils meeting the dexos1
specification are all that is needed for
good performance and engine
protection.
Engine oil system flushes are not
recommended and could cause engine
damage not covered by the vehicle
warranty.
What to Do with Used Oil
Used engine oil contains certain
elements that can be unhealthy for
your skin and could even cause
cancer. Do not let used oil stay on
your skin for very long. Clean your
skin and nails with soap and water,
or a good hand cleaner. Wash or
properly dispose of clothing or rags
containing used engine oil. See the
manufacturer's warnings about the
use and disposal of oil products.
Used oil can be a threat to the
environment. If you change your own
oil, be sure to drain all the oil from
the filter before disposal. Never
dispose of oil by putting it in the trashor pouring it on the ground, into
sewers, or into streams or bodies of
water. Recycle it by taking it to a place
that collects used oil.
Engine Oil Life System
When to Change Engine Oil
This vehicle has a computer system
that indicates when to change the
engine oil and filter. This is based on a
combination of factors which include
engine revolutions, engine
temperature, and miles driven. Based
on driving conditions, the mileage at
which an oil change is indicated can
vary considerably. For the oil life
system to work properly, the system
must be reset every time the oil is
changed.
When the system has calculated that
oil life has been diminished, it
indicates that an oil change is
necessary. A CHANGE ENGINE OIL
SOON message comes on. Change the
oil as soon as possible within the next
1 000 km (600 mi). It is possible that,
if driving under the best conditions,
the oil life system might indicate that
an oil change is not necessary for up
to a year. The engine oil and filter
must be changed at least once a year
and at this time the system must be
reset. Your dealer has trained service
people who will perform this work and
reset the system. It is also important
to check the oil regularly over the
course of an oil drain interval and
keep it at the proper level.
If the system is ever reset accidentally,
the oil must be changed at 5 000 km
(3,000 mi) since the last oil change.
Remember to reset the oil life system
whenever the oil is changed.
How to Reset the Engine Oil Life
System
Reset the system whenever the engine
oil is changed so that the system can
calculate the next engine oil change.
To reset the system:
1. Using the DIC buttons, display REMAINING OIL LIFE on the DIC.
See Driver Information Center (DIC)
(Base Level) 0113 or
Driver Information Center (DIC)
(Uplevel) 0116.

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
VEHICLE CARE 321
To inspect or replace the air cleaner/
filter:
2.0L L4 Engine
1. Remove the five screws on top of the air cleaner/filter cover.
2. Lift the air/cleaner/filter cover away from the air cleaner/filter housing.
3. Pull out the air cleaner/filter.
{Warning
If part replacement is necessary,
the part must be replaced with one
of the same part number or with an
equivalent part. Use of a
replacement part without the same (Continued)
Warning (Continued)
fit, form, and function may result in
personal injury or damage to the
vehicle.
4. Inspect or replace the air cleaner/ filter.
5. Reverse Steps 1–3 to reinstall the air cleaner/filter cover.
6. If equipped, reset the engine air filter life system after replacing the
engine air filter. See Engine Air
Filter Life System 0319.
3.0L V6 Engine
1. Air Duct Clamps 2. Electrical Connectors
3. Screws
1. Disconnect the harness connectors
from the air cleaner/filter cover
electrical connectors (2).
2. Loosen the screws on the air duct clamps (1) holding the air outlet
ducts in place. Do not remove
clamps. Move the ducts aside.
3. Remove the 13 screws (3) on top of the engine air cleaner/filter cover
to gain access to both air cleaner/
filters.
4. Lift the engine air cleaner/filter cover.
5. Lift and remove one or both engine air cleaner/filters.
6. Inspect or replace one or both engine air cleaner/filters.
7. Reverse Steps 1–4 to reinstall the engine air cleaner/filter cover.
8. If equipped, reset the engine air filter life system after replacing the
engine air filter. See Engine Air
Filter Life System 0319.

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
322 VEHICLE CARE
{Warning
Operating the engine with the air
cleaner/filter off can cause you or
others to be burned. Use caution
when working on the engine. Do
not start the engine or drive the
vehicle with the air cleaner/filter
off, as flames may be present if the
engine backfires.
Caution
If the air cleaner/filter is off, dirt
can easily get into the engine,
which could damage it. Always have
the air cleaner/filter in place when
driving.
Cooling System
The cooling system allows the engine
to maintain the correct working
temperature.
2.0L L4 Engine
1. Engine Coolant Surge Tank andPressure Cap
2. Engine Cooling Fan (Out of View)
3.0L V6 Engine
1. Engine Coolant Surge Tank and Pressure Cap
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.

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)

Cadillac CT5 Owner Manual (GMNA-Localizing-U.S./Canada-14584312) -
2021 - CRC - 11/23/20
328 VEHICLE CARE
Caution (Continued)
expansion if freezing occurs,
which could damage the tank if
it is completely full.
Brakes
Disc brake linings have built-in wear
indicators that make a high-pitched
warning sound when the brake linings
are worn and new linings are needed.
The sound can come and go or can be
heard all the time when the vehicle is
moving, except when applying the
brake pedal firmly.
{Warning
The brake wear warning sound
means that soon the brakes will not
work well. That could lead to a
crash. When the brake wear
warning sound is heard, have the
vehicle serviced.
Caution
Continuing to drive with worn-out
brake linings could result in costly
brake repairs.
Some driving conditions or climates
can cause a brake squeal when the
brakes are first applied, clearing up
following several applications. This
does not mean something is wrong
with the brakes.
Properly torqued wheel nuts are
necessary to help prevent brake
pulsation. When tires are rotated,
inspect brake linings for wear and
evenly tighten wheel nuts in the
proper sequence to torque
specifications. See Capacities and
Specifications 0397.
Brake pads should be replaced as
complete axle sets.
Brake Pedal Travel
See your dealer if the brake pedal does
not return to normal height, or if
there is a rapid increase in pedal
travel. This could be a sign that brake
service may be required.
Replacing Brake System Parts
Always replace brake system parts
with new, approved replacement parts.
If this is not done, the brakes may not
work properly. The braking
performance can change in many
ways if the wrong brake parts are
installed or if parts are improperly
installed.
Brake Pad Life System (If
Equipped)
When to Change Brake Pads
This vehicle has a system that
estimates the remaining life of the
front and rear brake pads. Brake pad
life is displayed in the Driver
Information Center (DIC), along with
a percentage for each axle. The system
must be reset every time the brake
pads are changed.
When the system has determined that
the brake pads need to be replaced, a
message will display, which may
include mileage remaining.
Brake pads should always be replaced
as complete axle sets.