2020 CADILLAC CT4 air conditioning

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
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

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
134 CLIMATE CONTROLS
Climate Controls
Climate Control Systems
Dual Automatic Climate ControlSystem . . . . . . . . . . . . . . . . . . . . . . . . . . 134
Air Vents
Air Vents . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Maintenance
Passenger Compartment AirFilter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
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
9. SYNC (Synchronized
Temperature)
10. Defrost
11. Rear Window Defogger

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
CLIMATE CONTROLS 135
Climate Control Display
1. Driver and PassengerTemperature 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, 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.
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.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
136 CLIMATE CONTROLS
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 control system
will turn on and deliver airf low 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 airf low. An indicator light comes

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
CLIMATE CONTROLS 137
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, 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 vents. 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 0139.
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
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 ignition is on. The defogger
turns off if the ignition is turned to
off or ACC/ACCESSORY.
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 027.
Remote Start Climate Control
Operation : If equipped with remote
start, the climate control system may

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
140 CLIMATE CONTROLS
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
0303.

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.