2020 CADILLAC CT6 maintenance

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
ContentsIntroduction . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Keys, Doors, and Windows . . . . . . . . . . 9
Seats and Restraints . . . . . . . . . . . . . . . 43
Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Instruments and Controls . . . . . . . . 102
Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
Infotainment System . . . . . . . . . . . . . 157
Climate Controls . . . . . . . . . . . . . . . . . . 158
Driving and Operating . . . . . . . . . . . . 171
Vehicle Care . . . . . . . . . . . . . . . . . . . . . . . 270
Service and Maintenance . . . . . . . . . 357
Technical Data . . . . . . . . . . . . . . . . . . . . 372
Customer Information . . . . . . . . . . . . 376
Reporting Safety Defects . . . . . . . . . 386
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 390
Connected Services . . . . . . . . . . . . . . . 397
Index . . . . . . . . . . . . . . . . . . . . . . . . 400

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
76 SEATS AND RESTRAINTS
Adding Equipment to the
Airbag-Equipped Vehicle
Adding accessories that change the
vehicle's frame, bumper system,
height, front end, or side sheet metal
may keep the airbag system from
working properly.
The operation of the airbag system
can also be affected by changing,
including improperly repairing or
replacing, any parts of the following:
.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 071. If the vehicle has rollover roof-rail
airbags, see
Different Size Tires and
Wheels 0333 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 0378.
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 0121.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
118 INSTRUMENTS AND CONTROLS
English, Standard Theme Shown
The engine oil pressure gauge shows
the engine oil pressure
in kPa (kilopascals) when the engine is
running.
Oil pressure can vary with engine
speed, outside temperature and oil
viscosity.
On some models, the oil pump will
vary engine oil pressure according to
engine needs. Oil pressure may change
quickly as the engine speed or load
varies. This is normal. If the oil pressure warning light or
Driver Information Center (DIC)
message indicates oil pressure outside
the normal operating range, check the
vehicle's oil as soon as possible. See
Engine Oil
0277.
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.
Engine Oil Temperature
Gauge (Performance
Configuration Only)
Metric Shown
This gauge shows the engine oil
temperature.
If the gauge pointer moves into the
high end, it means that the engine oil
has overheated. If the vehicle has been
operated under normal driving
conditions, pull off the road, stop the
vehicle, and turn off the engine as
soon as possible.
See Engine Oil 0277.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
INSTRUMENTS AND CONTROLS 123
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 Positions0183.
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 0272.
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 CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
124 INSTRUMENTS AND CONTROLS
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 0260. 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 (3.6L V6 Engine) 0258 or
Recommended Fuel (4.2L Twin
Turbo V8 Engine) 0259.
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 0269.
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 CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
130 INSTRUMENTS AND CONTROLS
For vehicles with the Tire Pressure
Monitor System (TPMS), this light
comes on briefly when the engine is
started. It provides information about
tire pressures and the TPMS.
When the Light Is On Steady
This indicates that one or more of the
tires are significantly underinflated.
A Driver Information Center (DIC) tire
pressure message may also display.
Stop as soon as possible, and inflate
the tires to the pressure value shown
on the Tire and Loading Information
label. SeeTire Pressure 0322.
When the Light Flashes First and
Then Is On Steady
If the light flashes for about a minute
and then stays on, there may be a
problem with the TPMS. If the
problem is not corrected, the light will
come on at every ignition cycle. See
Tire Pressure Monitor Operation 0325.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. For vehicles with a
reconfigurable cluster, this light is in
the display area and may not come on
when the ignition is turned on.
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.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
134 INSTRUMENTS AND CONTROLS
Average Speed :Shows the average
speed of the vehicle in kilometers per
hour (km/h) or miles per hour (mph).
This average is calculated based on
the various vehicle speeds recorded
since the last reset of this value. The
average speed can be reset by pressing
and holding SEL while this display is
active.
Timer : This display can be used as a
timer. To start the timer, press SEL
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 SEL
briefly while this display is active and
the timer is running. To reset the
timer to zero, press and hold SEL
while this display is active.
Compass (Uplevel Cluster) : Shows
the direction the vehicle is driving.
Speed Limit : Shows the current
speed limit. The information for this
page comes from a roadway database.
Speed Warning : Allows the driver to
set a speed that they do not want to
exceed. To set the Speed Warning,
press SEL when Speed Warning is displayed. Pressyorzto adjust the
value. This feature can be turned off
by pressing and holding SEL while
viewing this page. If the selected
speed limit is exceeded, a pop-up
warning is displayed and a chime may
sound.
Cruise Set Speed : Shows the speed
the cruise control or Adaptive Cruise
Control is set to.
Follow Distance : If equipped, the
current follow time to the vehicle
ahead is displayed as a time value on
this page.
Driver Assistance (Uplevel
Cluster) : May show information for
Lane Keep Assist (LKA), Lane
Departure Warning (LDW), Adaptive
Cruise Control (ACC), and Forward
Collision Alert (FCA). The display
shows if there is a vehicle detected
ahead, and the current FCA timing
setting. In addition, when ACC is not
engaged, the current follow time to
the vehicle ahead is displayed as a
time value on this page. Battery Voltage :
Shows the current
battery voltage.
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 Oil0277. In
addition to the engine oil life system
monitoring the oil life, additional
maintenance is recommended. See
Maintenance Schedule 0359.
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 and hold SEL for
several seconds while the Oil Life
display is active. See Engine Oil Life
System 0280.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
158 CLIMATE CONTROLS
Climate Controls
Climate Control Systems
Automatic Climate ControlSystem (Dual Zone) . . . . . . . . . . . . 158
Automatic Climate Control System (Quad Zone) . . . . . . . . . . . . 163
Air Vents
Air Vents . . . . . . . . . . . . . . . . . . . . . . . . . . 169
Maintenance
Passenger Compartment AirFilter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
Climate Control Systems
Automatic Climate Control System (Dual Zone)
The climate control buttons on the center stack and on the climate control
display are used to adjust the heating, cooling, and ventilation.
Center Stack Climate Controls
1. Driver and Passenger Temperature Controls
2. Fan Control
3. Driver and Passenger Heated and Ventilated Seats (If Equipped)
4. Rear Window Defogger 5. Defrost
6. OFF (Fan)
7. Recirculation
8. AUTO (Automatic Operation)