2021 CADILLAC CT4 coolant

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
320 VEHICLE CARE
{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.
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.
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 coolant to
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
0 219.
3.3. Turn off the air conditioning.
3.4. Set the parking brake.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
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VEHICLE CARE 321
3.5. At the same time, press theaccelerator 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.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
0 219.
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

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
322 VEHICLE CARE
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 0403.
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.
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

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
VEHICLE CARE 323
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. SeeEngine Compartment
Overview 0309 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.
(Continued)
Caution (Continued)
.Fill the washer fluid tank only
three-quarters full when it is very
cold. This allows for fluid
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.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
344 VEHICLE CARE
to carry. The speed rating is the
maximum speed a tire is certified
to carry a load.
Tire Terminology and
Definitions
Air Pressure:The amount of air
inside the tire pressing outward
on each square inch of the tire.
Air pressure is expressed in kPa
(kilopascal) or psi (pounds per
square inch).
Accessory Weight
:The combined
weight of optional accessories.
Some examples of optional
accessories are automatic
transmission, power windows,
power seats, and air conditioning.
Aspect Ratio
:The relationship of
a tire's height to its width.
Belt
:A rubber coated layer of
cords between the plies and the
tread. Cords may be made from
steel or other reinforcing
materials. Bead
:The tire bead contains steel
wires wrapped by steel cords that
hold the tire onto the rim.
Bias Ply Tire
:A pneumatic tire in
which the plies are laid at
alternate angles less than
90 degrees to the centerline of the
tread.
Cold Tire Pressure
:The amount
of air pressure in a tire, measured
in kPa (kilopascal) or psi (pounds
per square inch) before a tire has
built up heat from driving. See
Tire Pressure 0346.
Curb Weight
:The weight of a
motor vehicle with standard and
optional equipment including the
maximum capacity of fuel, oil, and
coolant, but without passengers
and cargo.
DOT Markings
:A code molded
into the sidewall of a tire
signifying that the tire is in
compliance with the U.S.
Department of Transportation
(DOT) Motor Vehicle Safety Standards. The DOT code includes
the Tire Identification Number
(TIN), an alphanumeric designator
which can also identify the tire
manufacturer, production plant,
brand, and date of production.
GVWR
:Gross Vehicle Weight
Rating. See Vehicle Load Limits
0 214.
GAWR FRT
:Gross Axle Weight
Rating for the front axle. See
Vehicle Load Limits 0214.
GAWR RR
:Gross Axle Weight
Rating for the rear axle. See
Vehicle Load Limits 0214.
Intended Outboard Sidewall
:
The side of an asymmetrical tire
that must always face outward
when mounted on a vehicle.
Kilopascal (kPa)
:The metric unit
for air pressure.
Light Truck (LT-Metric) Tire
:A
tire used on light duty trucks and
some multipurpose passenger
vehicles.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
SERVICE AND MAINTENANCE 381
oil life system must be reset. Your
trained dealer technician can perform
this work. If the engine oil life system
is reset accidentally, service the
vehicle within 5 000 km (3,000 mi)
since the last service. Reset the oil life
system when the oil is changed. See
Engine Oil Life System0314.
Air Conditioning Desiccant
(Replace Every Seven Years)
The air conditioning system requires
maintenance every seven years. This
service requires replacement of the
desiccant to help the longevity and
efficient operation of the air
conditioning system. This service can
be complex. See your dealer.
Tire Rotation and Required
Services Every 12 000 km
(7,500 mi)
Rotate the tires, if recommended for
the vehicle, and perform the following
services. See Tire Rotation0352.
.Check engine oil level and oil
life percentage. If needed, change
engine oil and filter, and reset oil
life system. See Engine Oil0312 and
Engine Oil Life System 0314.
.If equipped, check the air filter
life percentage. If necessary, replace
the engine air filter and reset the
engine air filter life system. See
Engine Air Filter Life System 0315.
If the vehicle is not equipped with
the engine air filter life system,
inspect the engine air cleaner filter.
See Engine Air Cleaner/Filter 0316.
.Check engine coolant level. See
Cooling System 0317.
.Check windshield washer fluid level.
See Washer Fluid 0323.
.Check tire inflation pressures. See
Tire Pressure 0346.
.Inspect tire wear. See Tire Inspection
0 352.
.Visually check for fluid leaks.
.Inspect brake system. See Exterior
Care 0370.
.Visually inspect steering,
suspension, and chassis
components for damage, including
cracks or tears in the rubber boots,
loose or missing parts, or signs of
wear at least once a year. See
Exterior Care 0370.
.Inspect power steering for proper
attachment, connections, binding,
leaks, cracks, chafing, etc.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
SERVICE AND MAINTENANCE 391
Recommended Fluids, Lubricants, and Parts
Recommended Fluids and Lubricants
Fluids and lubricants identified below by name or specification, including fluids or lubricants not listed here, can be
obtained from your dealer.Usage Fluid/Lubricant
Automatic Transmission (8-Speed Transmission) DEXRON-HP Automatic Transmission Fluid.
Automatic Transmission (10-Speed Transmission) DEXRON ULV Automatic Transmission Fluid.
Chassis Lubrication Chassis lubricant meeting requirements of NLGI #2, Category LB or GC-LB. Engine Coolant 50/50 mixture of clean, drinkable water and use only DEX-COOL Coolant. See Cooling System0317.
Engine Oil Engine oil meeting the dexos1 specification of the proper SAE viscosity grade. ACDelco dexos1 full synthetic is recommended. See Engine Oil0312.
Hood Latch Assembly, Secondary Latch,
Pivots, Spring Anchor, and Release Pawl Lubriplate Lubricant Aerosol or lubricant meeting requirements of NLGI #2,
Category LB or GC-LB.
Hydraulic Brake System DOT 4 Hydraulic Brake Fluid.
Key Lock Cylinders, Hood and Door Hinges Multi-Purpose Lubricant, Superlube. See your dealer.
Rear Axle/Front Axle (All-Wheel Drive) See your dealer. Windshield Washer Automotive windshield washer fluid that meets regional freeze protection requirements.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 11/23/20
INDEX 423
Chains, Tire . . . . . . . . . . . . . . . . . . . . . . . . . 358
ChargingWireless . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Charging System Light . . . . . . . . . . . . . . 97
Check Engine Light (MalfunctionIndicator) . . . . . . . . . . . . . . . . . . . . . . . . . 97
Child Restraints Infants and Young Children . . . . . . . 60
Lower Anchors and Tethersfor Children . . . . . . . . . . . . . . . . . . . . . . . 65
Older Children . . . . . . . . . . . . . . . . . . . . . 59
Securing . . . . . . . . . . . . . . . . . . . . . . . . 72, 74
Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Circuit Breakers . . . . . . . . . . . . . . . . . . . . . 331
Cleaning Exterior Care . . . . . . . . . . . . . . . . . . . . . . 370
Interior Care . . . . . . . . . . . . . . . . . . . . . . 375
Climate Control Systems Dual Automatic . . . . . . . . . . . . . . . . . . . 196
Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Cluster, Instrument . . . . . . . . . . . . . . 88, 90
Collision Damage Repair . . . . . . . . . . . 406
Compartments Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Compass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Competitive Driving Mode . . . . . . . . . 246
Composite Materials . . . . . . . . . . . . . . . . 218 Compressor Kit, Tire Sealant . . . . . . . 360
Connected Services
Connections . . . . . . . . . . . . . . . . . . . . . . . 419
Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . 420
Navigation . . . . . . . . . . . . . . . . . . . . . . . . . 418
Connections Connected Services . . . . . . . . . . . . . . . 419
Control Traction and ElectronicStability . . . . . . . . . . . . . . . . . . . . . . . . . . 239
Control of a Vehicle . . . . . . . . . . . . . . . . 204
Controls
Steering Wheel . . . . . . . . . . . . . . . . . . . . 137
Convex Mirrors . . . . . . . . . . . . . . . . . . . . . . 23
Coolant Engine Temperature Gauge . . . 94, 95
Engine Temperature Warning
Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
Cooling System . . . . . . . . . . . . . . . . . . . . . 317
Cornering Lamps . . . . . . . . . . . . . . . . . . . 130
Courtesy Lamps . . . . . . . . . . . . . . . . . . . . . 130
Courtesy Transportation Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405
Coverage Explanations . . . . . . . . . . . . . 163
Cruise Control . . . . . . . . . . . . . . . . . . . . . . . 248
Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Cruise Control, Adaptive . . . . . . . . . . . 251 Cruise Control, Super . . . . . . . . . . . . . . . 260
Cupholders . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Customer Assistance . . . . . . . . . . . . . . . 402
Offices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 401
Text Telephone (TTY) Users . . . . . 402
Customer Information Publications Ordering
Information . . . . . . . . . . . . . . . . . . . . . . 408
Customer Satisfaction Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . 399
Cybersecurity . . . . . . . . . . . . . . . . . . . . . . . . 410
D
Damage Repair, Collision . . . . . . . . . . . 406
Danger, Warning, and Caution . . . . . . . . 2
Data Collection Infotainment System . . . . . . . . . . . . . 412
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 412
Data Recorders, Event . . . . . . . . . . . . . . 411
Database Coverage Explanations . . . . . . . . . . . . . . . . . . . . . . 163
Daytime Running Lamps (DRL) . . . 128
Defensive Driving . . . . . . . . . . . . . . . . . . . 204
Delayed Locking . . . . . . . . . . . . . . . . . . . . . 17
Destination . . . . . . . . . . . . . . . . . . . . . . . . . . 155
Diagnostics Connected Services . . . . . . . . . . . . . . . 420
Differential, Limited-Slip . . . . . . . . . . . 248