2020 CADILLAC CT4 service

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
242 VEHICLE CARE
.If unable to wait two hours, the
engine must be off for at least
15 minutes if the engine is warm,
or at least 30 minutes if the
engine is not warm. Pull out the
dipstick, wipe it with a clean paper
towel or cloth, then push it back
in all the way. Remove it again,
keeping the tip down, and check
the level.
When to Add Engine Oil
If the oil is below the cross-hatched
area at the tip of the dipstick and the
engine has been off for at least
15 minutes, add 1 L (1 qt) of the
recommended oil and then recheck
the level. See “Selecting the Right
Engine Oil” later in this section for an
explanation of what kind of oil to use.
For engine oil crankcase capacity, see
Capacities and Specifications 0318.
Caution
Do not add too much oil. Oil levels
above or below the acceptable
operating range shown on the
dipstick are harmful to the engine.
If the oil level is above the
operating range (i.e., the engine has
so much oil that the oil level gets
above the cross-hatched area that
shows the proper operating range),
the engine could be damaged. Drain
the excess oil or limit driving of the
vehicle, and seek a service
professional to remove the
excess oil.
See Engine Compartment Overview
0 238 for the location of the engine oil
fill cap.
Add enough oil to put the level
somewhere in the proper operating
range. Push the dipstick all the way
back in when finished.
Selecting the Right Engine Oil
Selecting the right engine oil depends
on both the proper oil specification
and viscosity grade. See Recommended
Fluids and Lubricants 0313.
Specification
Use full synthetic engine oils that
meet the dexos1 specification. Engine
oils that have been approved by GM
as meeting the dexos1 specification
are marked with the dexos1 approved
logo. See www.gmdexos.com.
Caution
Failure to use the recommended
engine oil or equivalent can result
in engine damage not covered by
the vehicle warranty.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
VEHICLE CARE 243
Viscosity Grade
For the LSY 2.0L L4 turbo engine, use
SAE 0W-20 viscosity grade engine oil.
For the L3B 2.7L L4 turbo engine, use
SAE 5W-30 viscosity grade engine oil.
Cold Temperature Operation: In an
area of extreme cold, where the
temperature falls below−29 °C (−20 °
F), an SAE 0W-30 oil may be used. An
oil of this viscosity grade will provide
easier cold starting for the engine at
extremely low temperatures.
When selecting an oil of the
appropriate viscosity grade, it is
recommended to select an oil of the
correct specification. See
“Specification ”earlier in this section.
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 trash
or 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

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
VEHICLE CARE 247
{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.
Engine Coolant
The cooling system in the vehicle is
filled with DEX-COOL engine coolant.
SeeMaintenance Schedule 0303 and
Recommended Fluids and Lubricants
0 313.
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 0250.
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.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
VEHICLE CARE 249
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.
2.0L L4 Engine
Automatic Coolant Service Fill
Instructions
The vehicle is equipped with a service
feature that assists with filling and
removing air from the cooling system
after service of components or when
coolant is added after being to low.
To use this feature:
1. With a cold system, add coolantto the indicated line on the
surge tank.
2. Replace the pressure cap on the surge tank.
3. Activate the service feature: 3.1. Connect the vehicle to a battery charger.
3.2. Turn the ignition to Service Mode. See Ignition
Positions 0158.
3.3. Turn off the air conditioning.
3.4. Set the parking brake. 3.5. At the same time, press the
accelerator and the brake
pedal for two seconds, then
release.
3.6. At the end of the cycle, check the coolant level in
the surge tank and add
coolant if it is below the
indicated line. Turn the
ignition off, allow the
Electronic Control Module
(ECM) to go to sleep, about
two minutes, and repeat
Steps 3.2 –3.6.
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 pressure cap, refill to the indicated
line, replace the pressure cap, and
repeat steps 3.2 –3.6.
The fill and air removal process will
run for approximately 15 minutes.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
250 VEHICLE CARE
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.
2.7L L4 Engine
Automatic Coolant Service Fill
Instructions
The vehicle is equipped with a service
feature that assists with filling and
removing air from the cooling system
after service of components or when
coolant is added after being to low.
To use this feature:1. With a cold system unscrew the cooling system air bleeder cap.
If coolant can be seen through
the bleeder move to Step 3.
2. Add coolant through the surge tank until it is visible through
the air bleeder.
3. Replace the cooling system air bleeder cap. 4. Add coolant to the indicated line
on the surge tank.
5. Replace the pressure cap on the surge tank.
6. Activate the service feature:
6.1. Connect the vehicle to a battery charger.
6.2. Turn the ignition to Service Mode. See Ignition
Positions 0158.
6.3. Turn off the air conditioning.
6.4. Set the parking brake.
6.5. At the same time, press the accelerator and the brake
pedal for two seconds, then
release.
6.6. At the end of the cycle, check the coolant level in
the surge tank and add
coolant if it is below the
indicated line. Turn the
ignition off, carefully
remove the pressure cap,
refill to the indicated line,
replace the pressure cap,
and repeat steps 6.2 –6.6. 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 pressure cap, refill to the indicated
line, replace the pressure cap, and
repeat steps 6.2
–6.6.
The fill and air removal process will
run for approximately 15 minutes.
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 0325.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
VEHICLE CARE 251
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,(Continued)
Warning (Continued)
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.
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.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
252 VEHICLE CARE
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. SeeEngine Compartment
Overview 0238 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 expansion if freezing
(Continued)
Caution (Continued)
occurs, which could damage
the tank if it is
completely full.
Brakes
Disc brake pads have built-in wear
indicators that make a high-pitched
warning sound when the brake pads
are worn and new pads are needed.
The sound can come and go or 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.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
VEHICLE CARE 253
Caution
Continuing to drive with worn-out
brake pads could result in costly
brake repair.
Some driving conditions or climates
can cause a brake squeal when the
brakes are first applied or lightly
applied. This does not mean
something is wrong with the brakes.
If equipped with high performance
brake linings, there could be an
increased build-up of brake dust as
well as minor noises as compared to
standard brake linings.
Properly torqued wheel nuts are
necessary to help prevent brake
pulsation. When tires are rotated,
inspect brake pads for wear and
evenly tighten wheel nuts in the
proper sequence to torque
specifications. See Capacities and
Specifications 0318.
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 expected can change in
many other ways if the wrong
replacement brake parts are installed
or parts are improperly installed.
Brake Fluid
The brake master cylinder reservoir is
filled with GM approved DOT 3 brake
fluid as indicated on the reservoir cap.
See Engine Compartment Overview
0 238 for the location of the reservoir.
Checking Brake Fluid
With the vehicle in P (Park) on a level
surface, the brake fluid level should be
between the minimum and maximum
marks on the brake fluid reservoir.
There are only two reasons why the
brake fluid level in the reservoir may
go down:
. Normal brake lining wear. When
new linings are installed, the fluid
level goes back up.
. A fluid leak in the brake hydraulic
system. Have the brake hydraulic
system fixed. With a leak, the
brakes will not work well.
Always clean the brake fluid reservoir
cap and the area around the cap
before removing it.
Do not top off the brake fluid. Adding
fluid does not correct a leak. If fluid is
added when the linings are worn,
there will be too much fluid when