2020 CADILLAC CT4 maintenance

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
ContentsIntroduction . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Keys, Doors, and Windows . . . . . . . . . . 7
Seats and Restraints . . . . . . . . . . . . . . . 33
Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Instruments and Controls . . . . . . . . . . 85
Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
Infotainment System . . . . . . . . . . . . . 133
Climate Controls . . . . . . . . . . . . . . . . . . 134
Driving and Operating . . . . . . . . . . . . 141
Vehicle Care . . . . . . . . . . . . . . . . . . . . . . . 233
Service and Maintenance . . . . . . . . . 302
Technical Data . . . . . . . . . . . . . . . . . . . . 317
Customer Information . . . . . . . . . . . . 321
Reporting Safety Defects . . . . . . . . . 331
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335
Connected Services . . . . . . . . . . . . . . . 341
Index . . . . . . . . . . . . . . . . . . . . . . . . 344

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
62 SEATS AND RESTRAINTS
.Airbag system, including airbag
modules, front or side impact
sensors, sensing and diagnostic
module, or airbag wiring
. Front seats, including stitching,
seams or zippers
. Seat belts
. Steering wheel, instrument panel,
overhead console, ceiling trim,
or pillar garnish trim
. Inner door seals, including
speakers
Your dealer and the service manual
have information about the location of
the airbag modules and sensors,
sensing and diagnostic module, and
airbag wiring along with the proper
replacement procedures.
In addition, the vehicle has a
passenger sensing system for the front
outboard passenger position, which
includes sensors that are part of the
passenger seat. The passenger sensing
system may not operate properly if
the original seat trim is replaced with
non-GM covers, upholstery, or trim; or
with GM covers, upholstery, or trim
designed for a different vehicle. Any object, such as an aftermarket seat
heater or a comfort-enhancing pad or
device, installed under or on top of
the seat fabric, could also interfere
with the operation of the passenger
sensing system. This could either
prevent proper deployment of the
passenger airbag(s) or prevent the
passenger sensing system from
properly turning off the passenger
airbag(s). See
Passenger Sensing
System 057.
If the vehicle has rollover roof-rail
airbags, see Different Size Tires and
Wheels 0284 for additional important
information.
If the vehicle must be modified
because you have a disability and have
questions about whether the
modifications will affect the vehicle's
airbag system, or if you have
questions about whether the airbag
system will be affected if the vehicle is
modified for any other reason, call
Customer Assistance. See Customer
Assistance Offices 0323.Airbag System Check
The airbag system does not need
regularly scheduled maintenance or
replacement. Make sure the airbag
readiness light is working. See Airbag
Readiness Light 098.
Caution
If an airbag covering is damaged,
opened, or broken, the airbag may
not work properly. Do not open or
break the airbag coverings. If there
are any opened or broken airbag
coverings, have the airbag covering
and/or airbag module replaced. For
the location of the airbags, see
Where Are the Airbags? 053. See
your dealer for service.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
100 INSTRUMENTS AND CONTROLS
If the light stays on, or comes on
while driving, there may be a problem
with the electrical charging system.
Have it checked by your dealer.
Driving while this light is on could
drain the battery.
When this light comes on, or is
flashing, the Driver Information
Center (DIC) also displays a message.
If a short distance must be driven
with the light on, be sure to turn off
all accessories, such as the radio and
air conditioner.
Malfunction Indicator Lamp
(Check Engine Light)
This light is part of the vehicle’s
emission control on-board diagnostic
system. If this light is on while the
engine is running, a malfunction has
been detected and the vehicle may
require service. The light should come
on to show that it is working when
the ignition is in Service Mode. See
Ignition Positions0158.
Malfunctions are often indicated by
the system before any problem is
noticeable. Being aware of the light
and seeking service promptly when it
comes on may prevent damage.
Caution
If the vehicle is driven continually
with this light on, the emission
control system may not work as
well, the fuel economy may be
lower, and the vehicle may not run
smoothly. This could lead to costly
repairs that might not be covered
by the vehicle warranty.
Caution
Modifications to the engine,
transmission, exhaust, intake,
or fuel system, or the use of
replacement tires that do not meet
the original tire specifications, can
cause this light to come on. This
could lead to costly repairs not
covered by the vehicle warranty.
This could also affect the vehicle’s
ability to pass an Emissions
Inspection/Maintenance test. See
Accessories and Modifications 0235.
If the light is f lashing : A
malfunction has been detected that
could damage the emission control
system and increase vehicle
emissions. Diagnosis and service may
be required.
To help prevent damage, reduce
vehicle speed and avoid hard
accelerations and uphill grades.
If towing a trailer, reduce the amount
of cargo being hauled as soon as
possible.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
INSTRUMENTS AND CONTROLS 101
If the light continues to flash, find a
safe place to park. Turn the vehicle off
and wait at least 10 seconds before
restarting the engine. If the light is
still flashing, follow the previous
guidelines and see your dealer for
service as soon as possible.
If the light is on steady :A
malfunction has been detected.
Diagnosis and service may be
required.
Check the following:
. If fuel has been added to the
vehicle using the capless fuel
funnel adapter, make sure that it
has been removed. See “Filling the
Tank with a Portable Gas Can ”
under Filling the Tank 0222. The
diagnostic system can detect if the
adapter has been left installed in
the vehicle, allowing fuel to
evaporate into the atmosphere.
A few driving trips with the
adapter removed may turn off the
light.
. Poor fuel quality can cause
inefficient engine operation and
poor driveability, which may go
away once the engine is warmed up. If this occurs, change the fuel
brand. It may require at least one
full tank of the proper fuel to turn
the light off. See
Recommended
Fuel (LSY 2.0L L4 Turbo Engine)
0 221 or
Recommended Fuel (L3B 2.7L L4
Turbo Engine) 0221.
If the light remains on, see your
dealer.
Emissions Inspection and
Maintenance Programs
If the vehicle requires an Emissions
Inspection/Maintenance test, the test
equipment will likely connect to the
vehicle's Data Link Connector (DLC).
The DLC is under the instrument
panel to the left of the steering wheel.
Connecting devices that are not used
to perform an Emissions Inspection/
Maintenance test or to service the vehicle may affect vehicle operation.
See
Add-On Electrical Equipment 0231.
See your dealer if assistance is needed.
The vehicle may not pass
inspection if:
. The light is on when the engine is
running.
. The light does not come on when
the ignition is in Service Mode.
. Critical emission control systems
have not been completely
diagnosed. If this happens, the
vehicle would not be ready for
inspection and might require
several days of routine driving
before the system is ready for
inspection. This can happen if the
12-volt battery has recently been
replaced or run down, or if the
vehicle has been recently serviced.
See your dealer if the vehicle will not
pass or cannot be made ready for
the test.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
INSTRUMENTS AND CONTROLS 107
Engine Oil Pressure Light
Caution
Lack of proper engine oil
maintenance can damage the
engine. Driving with the engine oil
low can also damage the engine.
The repairs would not be covered
by the vehicle warranty. Check the
oil level as soon as possible. Add oil
if required, but if the oil level is
within the operating range and the
oil pressure is still low, have the
vehicle serviced. Always follow the
maintenance schedule for changing
engine oil.
This light should come on briefly as
the engine is started. If it does not
come on, have the vehicle serviced by
your dealer.If the light comes on and stays on, it
means that oil is not flowing through
the engine properly. The vehicle could
be low on oil and might have some
other system problem. See your dealer.
Low Fuel Warning Light
This light is near the fuel gauge and
comes on briefly when the ignition is
turned on as a check to show it is
working.
It also comes on when the fuel tank is
low on fuel. The light turns off when
fuel is added. If it does not, have the
vehicle serviced.
Security Light
The security light should come on
briefly as the engine is started. If it
does not come on, have the vehicle
serviced by your dealer. If the system
is working normally, the indicator
light turns off.
If the light stays on and the engine
does not start, there could be a
problem with the theft-deterrent
system. See
Immobilizer Operation
0 24.
High-Beam On Light

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-13183937) -
2020 - crc - 4/28/20
110 INSTRUMENTS AND CONTROLS
L/100 km (mpg) recorded since the
last time this menu item was reset.
This number reflects only the
approximate average fuel economy
that the vehicle has right now, and
will change as driving conditions
change. The Average Fuel Economy
can be reset by pressing
Vand
selecting yes or no while this display
is active.
Fuel Range : Shows the approximate
distance the vehicle can be driven
without refueling. LOW will be
displayed when the vehicle is low on
fuel. The fuel range estimate is based
on an average of the vehicle's fuel
economy over recent driving history
and the amount of fuel remaining in
the fuel tank.
Oil Life : Shows an estimate of the
oil's remaining useful life.
If REMAINING OIL LIFE 99% is
displayed, that means 99% of the
current oil life remains.
When the remaining oil life is low, the
CHANGE ENGINE OIL SOON message
will appear on the display. The oil
should be changed as soon as
possible. See Engine Oil0241. In addition to the engine oil life system
monitoring the oil life, additional
maintenance is recommended. See
Maintenance Schedule
0303.
The Oil Life display must be reset
after each oil change. It will not reset
itself. Do not reset the Oil Life display
accidentally at any time other than
when the oil has just been changed.
It cannot be reset accurately until the
next oil change. To reset the engine
oil life system, press
Vand then
select yes or no. See Engine Oil Life
System 0243.
Tire Pressure : Shows the
approximate pressures of all four tires.
Tire pressure is displayed in either
kilopascal (kPa) or in pounds per
square inch (psi). If the pressure is
low, the value for that tire is shown in
amber. See Tire Pressure Monitor
System 0276 and
Tire Pressure Monitor Operation 0277.
Fuel Economy : Displays average fuel
economy, the best fuel economy over
the selected distance, and a bar graph
showing instantaneous fuel economy. Average Speed :
Displays the average
vehicle speed of the vehicle in
kilometers per hour (km/h) or miles
per hour (mph). This average is based
on the various vehicle speeds recorded
since the last reset. Reset the average
speed by pressing the thumbwheel
while this display is active to show a
confirmation window to select yes
or no.
Timer : This display can be used as a
timer. To start the timer, press the
thumbwheel while this display is
active. The display will show the
amount of time that has passed since
the timer was last reset. To stop the
timer, press the thumbwheel briefly
while this display is active and the
timer is running.
Press the thumbwheel while this
display is active to reset the timer.
Follow Distance/Gap Setting : When
Adaptive Cruise Control (ACC) is not
engaged, the current follow time to
the vehicle ahead is displayed as a
time value on this page. When ACC
has been engaged, the display

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 139
Air Vents
Adjustable air vents are in the center
and on the sides of the instrument
panel, and on the rear of the center
console storage.
Move the slider knobs to change the
direction of or to close off the airf low.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 Schedule 0303.
See your dealer regarding replacement
of the filter.