2023 CADILLAC CT4 air conditioning

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Introduction 3
Danger, Warning, and
Caution
Warning messages found on
vehicle labels and in this
manual describe hazards and
what to do to avoid or
reduce them.
{Danger
Danger indicates a hazard
with a high level of risk
which will result in serious
injury or death.
{Warning
Warning indicates a hazard
that could result in injury or
death.
Caution
Caution indicates a hazard
that could result in property
or vehicle damage.
A circle with a slash through it
is a safety symbol which
means“Do not,” “Do not do
this,” or“Do not let this
happen.”
Symbols
The vehicle has components
and labels that use symbols
instead of text. Symbols are
shown along with the text
describing the operation or
information relating to a
specific component, control,
message, gauge, or indicator.
M: Shown when the owner’s
manual has additional
instructions or information.
*: Shown when the service
manual has additional
instructions or information.
0: Shown when there is more
information on another page —
“see page.”
Vehicle Symbol Chart
Here are some additional
symbols that may be found on
the vehicle and what they
mean. See the features in this
manual for information.
u: Air Conditioning System
G:Air Conditioning
Refrigerant Oil
9: Airbag Readiness Light
!:Antilock Brake
System (ABS)
$: Brake System Warning
Light
9: Dispose of Used
Components Properly
P: Do Not Apply High
Pressure Water
B: Engine Coolant
Temperature
_: Flame/Fire Prohibited

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Climate Controls 225
Climate Controls
Climate Control Systems
Dual Automatic ClimateControl System . . . . . . . . . . . 225
Air Vents
Air Vents . . . . . . . . . . . . . . . . . . . . . 230
Maintenance
Passenger CompartmentAir Filter . . . . . . . . . . . . . . . . . . . . . 231
Service . . . . . . . . . . . . . . . . . . . . . . . . 231
Climate Control Systems
Dual Automatic Climate Control System
The climate control buttons on the center stack and on the
climate control display are used to adjust the heating, cooling,
and ventilation system. Center
Stack Climate Controls
1. ON/OFF (Power)
2. AUTO (Automatic
Operation)
3. Air Delivery Mode Control
4. Driver Temperature Controls 5. Fan Control
6. Passenger Temperature
Controls
7. A/C (Air Conditioning)
8. Recirculation

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
226 Climate Controls
9. SYNC (SynchronizedTemperature)
10. Defrost
11. Rear Window Defogger
Climate Control Display
1. Driver and Passenger Temperature Displays
2. Fan Control
3. Driver and Passenger Temperature Controls 4. Sync (Synchronized
Temperature)
5. Recirculation
6. Air Delivery Mode Control
7. Auto (Automatic Operation)
8. A/C (Air Conditioning)
9. On/Off (Power)
The fan speed, air delivery
mode, air conditioning, driver
and passenger temperatures,
recirculation, and Sync
settings can be controlled by
touching CLIMATE icon on the
infotainment Home Page or
the climate button in the
application tray. A selection
can then be made on the front
climate control page displayed.
See the infotainment manual.
Climate Control Status Display
The climate control status
display appears briefly when
the center stack climate
controls are adjusted.
Climate Control Influence
on Fuel Economy
The climate control system
depends on other vehicle
systems for heat and power
input. Certain climate control
settings can lead to higher
fuel usage.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Climate Controls 227
The following climate control
settings use more fuel:
.MAX air conditioning mode
.Defrost mode
.Extreme temperature
settings, such as 15° C
(60° F) or 32° C (90° F)
.High fan speed settings
To help reduce fuel usage:
.Use the full automatic
control as described under
“Automatic Operation.”
.Select a temperature setting
that is higher in hot weather
and lower in cold weather.
.Turn off the air conditioning
when it is not needed.
.Only use defrost to clear the
windows.
Automatic Operation
The system automatically
controls the following four
functions to heat or cool the
vehicle to the desired
temperature:
.Fan Speed
.Air Delivery Mode
.Air Conditioning
.Recirculation
When the AUTO indicator light
is lit, all four functions are
operating automatically. Each
function can be manually set
and the selected setting will
be shown. This cancels full
automatic operation and the
AUTO indicator light turns off.
Functions that are not
manually set will continue to
be automatically controlled,
although the AUTO indicator
light will not be lit.
To place the system in
automatic mode: 1. Press AUTO.
2. Set the driver and passenger temperature.
To find your comfort
setting, start with 22 °C
(72 °F) and allow the
system time to stabilize.
Then adjust the
temperature as needed for
best comfort. To improve fuel efficiency and
to cool the vehicle faster,
recirculation may be
automatically selected in warm
weather.
The recirculation light will not
come on when automatically
controlled. Press
@to
manually select recirculation;
press it again to select
outside air.
Do not cover the solar sensor
on the top of the instrument
panel near the windshield.
This sensor regulates air
temperature based on sun
load. See “Sensors” later in
this section.
Manual Operation
On/Off : Press to turn the
climate control system on or
off. When the system is off,
outside air will be prevented
from entering the vehicle.
When the system is on or a
button is pressed, the climate

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
228 Climate Controls
control system will turn on and
deliver airflow per the current
setting.
9:Press button up or down
to increase or decrease the
fan speed.
Press AUTO to return to
automatic operation.
Driver and Passenger
Temperature Control : The
temperature can be adjusted
separately for the driver and
passenger.
Press button up or down to
increase or decrease the
driver or passenger
temperature setting.
The driver side or passenger
side temperature display
shows the temperature
setting increasing or
decreasing.
SYNC : Press to link the
passenger and rear climate
temperature settings,
if equipped, to the driver
setting. The SYNC indicator
light will turn on. When the passenger or rear climate
temperature settings are
adjusted, the SYNC indicator
light is off.
Air Delivery Mode Control :
Press
Y,[, orzto change
the direction of the airflow. An
indicator light comes on in the
selected mode button. Multiple
buttons can be selected
simultaneously.
Changing the mode cancels
the automatic operation and
the system goes into manual
mode. Press AUTO to return
to automatic operation.
z: This mode clears the
windows of fog or moisture.
Air is directed to the
windshield and side window
vents. The system
automatically forces outside
air into the vehicle and the air
conditioning compressor will
run, unless the outside
temperature is close to
freezing.
Y: Air is directed to the
instrument panel outlets.
[: Air is directed to the floor
outlets, with some to the
windshield, side window
outlets, outboard panel
outlets, and second row floor
outlets.
0: Press to clear the
windshield of fog or frost
more quickly. Air is directed to
the windshield and the side
window outlets. The air
conditioning compressor also
comes on, unless the outside
temperature is below freezing.
Do not drive the vehicle until
all windows are clear.
See Air Vents 0230.
A/C : Press to turn the air
conditioning system on or off.
An indicator light comes on to
show that the air conditioning
is enabled. If the fan is turned
off, the air conditioner will not
run. The A/C light will stay on

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Climate Controls 229
even if the outside
temperatures are below
freezing.
@:Press to turn on
recirculation. An indicator light
comes on. Air is recirculated to
quickly cool the inside of the
vehicle. It can also be used to
help reduce outside air and
odors that enter the vehicle.
The air conditioning
compressor also comes on
when this mode is activated.
Rear Window Defogger
The rear window defogger
uses a warming grid to remove
fog from the rear window.
K: Press to turn the rear
window defogger on or off. An
indicator light on the button
comes on to show that the
rear window defogger is on.
The rear window defogger
only works when the vehicle is
on. The defogger can be
turned off by turning the
vehicle off or to
accessory mode.
Caution
Using a razor blade or sharp
object to clear the inside
rear window can damage
the rear window defogger.
Repairs would not be
covered by the vehicle
warranty. Do not clear the
inside rear window with
sharp objects.
Heated Mirror : If equipped
with heated outside mirrors,
the mirrors heat to help clear
fog or frost from the surface
of the mirror when the rear
window defog button is
pressed. See Heated Mirrors
0 30.
Remote Start Climate
Control Operation :
If equipped with remote start,
the climate control system
may run when the vehicle is
started remotely. The rear
defog may come on during
remote start based on cold ambient conditions. The rear
defog indicator light does not
come on during a remote start.
If equipped, the heated seats
will turn on if it is cold outside
or the ventilated seats will
turn on if it is hot outside. The
heated and ventilated seat
indicator lights may not come
on during a remote start.
If equipped, the heated
steering wheel will come on in
a remote start if it is cold
outside. The heated steering
wheel indicator light may not
come on.
Ionizer :
If equipped with an
ionizer, this feature helps to
clean the air inside the vehicle
and remove contaminants
such as pollen, odors, and
dust. If the climate control
system is on and the ionizer is
enabled, the ionizer status
indicator will be lit on the
climate control display. To turn
the Ionizer off or on, select

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
Climate Controls 231
Operation Tips
.Clear away any ice, snow,
or leaves from air inlets at
the base of the windshield
that could block the flow of
air into the vehicle.
.Clear snow off the hood to
improve visibility and help
decrease moisture drawn
into the vehicle.
.Keep the path under the
front seats clear of objects
to help circulate the air
inside of the vehicle more
effectively.
.Use of non-GM approved
hood deflectors can
adversely affect the
performance of the system.
Check with your dealer
before adding equipment to
the outside of the vehicle.
.Do not attach any devices to
the air vent slats. This
restricts airflow and may
cause damage to the air
vents.
Maintenance
Passenger
Compartment Air
Filter
The filter reduces dust, pollen,
and other airborne irritants
from outside air that is pulled
into the vehicle. The filter
should be replaced as part of
routine scheduled
maintenance. See
Maintenance Schedule0469.
See your dealer regarding
replacement of the filter.
Service
All vehicles have a label
underhood that identifies the
refrigerant used in the vehicle.
The refrigerant system should
only be serviced by trained
and certified technicians. The
air conditioning evaporator
should never be repaired or
replaced by one from a
salvage vehicle. It should only be replaced by a new
evaporator to ensure proper
and safe operation.
During service, all refrigerants
should be reclaimed with
proper equipment. Venting
refrigerants directly to the
atmosphere is harmful to the
environment and may also
create unsafe conditions
based on inhalation,
combustion, frostbite, or other
health-based concerns.
The air conditioning system
requires periodic maintenance.
See Maintenance Schedule
0
469.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-16500442) -
2023 - CRC - 5/4/22
390 Vehicle Care
To use this feature:
1. With a cold system, addcoolant 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 0261.
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.
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.