Page 392 of 524

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Vehicle Care 391
2. Add coolant through thesurge 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 0261.
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
Assistance Program 0487.
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.
Page 393 of 524

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
392 Vehicle Care
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 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.
Page 411 of 524
Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
410 Vehicle Care
Fuses Usage
1–
2 Heating, Ventilation, and Air Conditioning
Blower
3 –
4 –
5 Theft Deterrent/ Universal Garage Door
Opener/Overhead
Console/Rain Sensor
6 –
Fuses Usage
7 Air Quality Ionizer
8 Heated Steering Wheel
9 –
10 Electronic Steering Column Lock 1
11 –
12 –
13 –
Fuses Usage
14–
15 –
16 –
17 –
18 Display/Infotainment/ USB/Multi-function
Control Module
19 Sensing and Diagnostic Module/
Automatic Occupant
Sensing/Data Link
Connection/Wireless
Charging Module/
Virtual Key Module
20 Power Steering Column Module/
Electronic Steering
Column Lock 2
21 Driver Monitor System/Performance
Data Recorder
22 –
23 –
24 –
25 USB
26 –
27 –
28 –
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Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
472 Service and Maintenance
pressure water can
overcome the seals and
contaminate the transfer
case fluid. Contaminated
fluid will decrease the life of
the transfer case and/or
axles and should be
replaced.
.Change front axle fluid,
if equipped with AWD. Do
not directly power wash the
transfer case and/or front/
rear axle output seals. High
pressure water can
overcome the seals and
contaminate the transfer
case fluid. Contaminated
fluid will decrease the life of
the transfer case and/or
axles and should be
replaced.
Every 120 000 km
(75,000 mi)
.Change rear axle fluid,
without limited slip
differential. Do not directly
power wash the transfer
case and/or front/rear axle
output seals. High pressure water can overcome the
seals and contaminate the
transfer case fluid.
Contaminated fluid will
decrease the life of the
transfer case and/or axles
and should be replaced.
Owner Checks and
Services
Every Five Years
.Replace brake fluid every
five years. See Brake Fluid
0
398.
Every Seven Years
.Replace Air Conditioning
Desiccant 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.
Multi-Point Vehicle
Inspection (MPVI)
A Multi Point Vehicle
Inspection (MPVI) completed
by a GM dealer technician is a
maintenance assessment of
your vehicle. The benefit of
the MPVI is to identify and
inform the customer of service
items that require immediate
attention and those that may
require attention in the future.
The technician will perform the
following checks on your
vehicle. For a complete list of
checks, inspections, and
services, see your dealer.
Some items may not apply to
your vehicle and/or region.
Diagnostics
.OnStar active, if equipped
.Service history/recall check
Engine Oil and Filter
.Engine oil
.Oil life monitor
‐ Reset oil life monitor
Page 481 of 524
Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
480 Technical Data
Vehicle Data
Capacities and Specifications
ApplicationCapacities
Metric English
Air Conditioning Refrigerant For the air conditioning system refrigerant type and
charge amount, see the refrigerant label under the hood. See your dealer for more information.
Engine Cooling System*
I2.0L L4 Engine 10.4 L
11.0 qt
I2.7L L4 Engine 13.0 L
13.7 qt
I3.6L V6 Engine 13.6 L
14.4 qt
I3.6L V6 Engine Intercoolers (V-Series Blackwing) 2.7 L
2.9 qt
Engine Oil with Filter I2.0L L4 Engine 5.0 L
5.3 qt
I2.7L L4 Engine 5.7 L
6.0 qt
I3.6L V6 Engine 6.6 L
7.0 qt
Fuel Tank 66.0 L17.5 gal
Transfer Case –AWD 0.78 L0.8 qt
Front Axle –AWD 0.4 L0.42 qt
Page 510 of 524

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/10/22
INDEX 509
IndexA
Accessories andModifications . . . . . . . . . . . . . . . . 370
Accessory Power . . . . . . . . . . . .267
Active Rev Match . . . . . . . . . . . . . . . . . . . 285
Adaptive Cruise Control . . . . . . . . . . . . . . 304
Add-On Electrical Equipment . . . . . . . . . . . . . . . . . . . 366
Additional OnStar Information . . . . . . . . 501
Adjustments Lumbar, Front Seats . . . . . . . 40
Thigh Support . . . . . . . . . . . . . . . . 39
Agreements Trademarks andLicense . . . . . . . . . . . . . . . . . . . . . . 215
Air
Cleaner/Filter, Engine . . . . 384
Conditioning . . . . . . . . . . . . . . . . 225
Filter Life System . . . . . . . . . 383
Filter, PassengerCompartment . . . . . . . . . . . . . . 231
Vents . . . . . . . . . . . . . . . . . . . . . . . . . . 230
Airbag System . . . . . . . . . . . . . . . . . 59 Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 Airbag System (cont'd)
How Does an Airbag
Restrain? . . . . . . . . . . . . . . . . . . . . . 64
Passenger Sensing System . . . . . . . . . . . . . . . . . . . . . . . . 66
What Makes an Airbag Inflate? . . . . . . . . . . . . . . . . . . . . . . . . 63
What Will You See after an Airbag
Inflates? . . . . . . . . . . . . . . . . . . . . . . 64
When Should an Airbag Inflate? . . . . . . . . . . . . . . . . . . . . . . . . 62
Where Are the Airbags? . . . . . . . . . . . . . . . . . . . . . . . 61
Airbags Adding Equipment to
the Vehicle . . . . . . . . . . . . . . . . . . . 70
Passenger Status Indicator . . . . . . . . . . . . . . . . . . . . . . 117
Readiness Light . . . . . . . . . . . . . 116
Replacing System Parts after a Crash . . . . . . . 72
Servicing Airbag-Equipped
Vehicles . . . . . . . . . . . . . . . . . . . . . . 70
Alarm
Vehicle Security . . . . . . . . . . . . . 24