engine CADILLAC CT6 2020 Repair Manual

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/14/19
DRIVING AND OPERATING 197
To shift into D (Drive):1. Bring the vehicle to a complete stop.
2. From the center position, move the shift lever back.
.If the vehicle is in P (Park)
press the shift lock release
button while pulling the shift
lever back.
. D will illuminate in red.
. After releasing the shift lever,
it will return to the center
position.
To shift out of D (Drive): 1. Bring the vehicle to a complete stop.
2. Shift to the desired gear.
3. After releasing the shift lever, it will return to the center position.
Downshifting the transmission in
slippery road conditions could result
in skidding. See “Skidding”underLoss
of Control 0175. M :
This mode can be entered from
D (Drive) by pulling back on the shift
lever. The M in the shift pattern will
illuminate red, and the D will switch
to white. After releasing the shift
lever, it will return to the center
position. M (Manual Mode) allows
gears appropriate for current driving
conditions to be selected.
To exit M (Manual Mode) and return
to D (Drive), pull back on the shift
lever. The D in the shift pattern will
illuminate in red, and the M will
switch to white. See Manual Mode
0 197.
Caution
Spinning the tires or holding the
vehicle in one place on a hill using
only the accelerator pedal may
damage the transmission. The
repair will not be covered by the
vehicle warranty. If the vehicle is
stuck, do not spin the tires. When
stopping on a hill, use the brakes to
hold the vehicle in place.
Manual Mode
Tap Shift
Caution
Driving with the engine at a high
rpm without upshifting while using
Tap Shift, could damage the vehicle.
Always upshift when necessary
while using Tap Shift.
Vehicles with Tap Shift have controls
on the back of the steering wheel to
manually shift the automatic
transmission.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/14/19
198 DRIVING AND OPERATING
Permanent Tap Shift Mode
To enter Permanent Tap Shift Mode:1. With the vehicle in D (Drive), pull back on the shift lever to
activate M (Manual Mode). The
M in the shift pattern will
illuminate in red, and the D will
switch to white.
2. After releasing the shift lever, it will return to the center position.
3. Press the controls on the back of the steering wheel to shift. Use
the left steering wheel control to
downshift, and the right control
to upshift. To shift to the lowest
available gear, press and hold the
left control.
To exit Permanent Tap Shift Mode: 1. To exit M (Manual Mode) and return to D (Drive), pull back on
the shift lever. The D in the shift
pattern will illuminate in red,
and the M will switch to white.
2. After releasing the shift lever, it will return to the center position. M (Manual Mode) can be exited to
return to D (Drive) at any speed by
pulling the lever rearward from the
center position. It is not necessary to
stop the vehicle or shift to N (Neutral)
or P (Park) before shifting back to
D (Drive).
Temporary Tap Manual Shift Mode
To enter Temporary Tap Shift Mode:
1. With the transmission in D (Drive) and not in Permanent
Tap Shift Mode, the Tap Shift
controls will activate a
temporary tap manual shift
mode, allowing the transmission
to be manually shifted.
2. To shift to the lowest available gear, press and hold the left
control.
3. To deactivate, hold the right control briefly. Automatic shifts
return after no manual shifts
have been done for seven to
10 seconds. While using Tap Shift, the vehicle will
have firmer, quicker shifting. This can
be used for sport driving or when
climbing or descending hills, to stay in
gear longer, or to downshift for more
power or engine braking.
The transmission will only allow
shifting into gears appropriate for the
vehicle speed and engine revolutions
per minute (rpm). If shifting is
prevented for any reason, a SHIFT
DENIED message will be displayed in
the instrument cluster. The
transmission will not automatically
shift to the next higher gear if the
engine rpm is too high. It will only
automatically shift to the next lower
gear if the engine rpm is much
too low.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/14/19
DRIVING AND OPERATING 199
Drive Systems
All-Wheel Drive
Vehicles with this feature always send
engine power to all four wheels. It is
fully automatic, and adjusts itself as
needed for road conditions.
Brakes
Electric Brake Boost
Vehicles equipped with electric brake
boost have hydraulic brake circuits
that are electronically controlled when
the brake pedal is applied during
normal operation. The system
performs routine tests and turns off
within a few minutes after the vehicle
is shutdown. Noise may be heard
during this time. If the brake pedal is
pressed during the tests or when the
electric brake boost system is off, a
noticeable change in pedal force and
travel may be felt. This is normal.
Antilock Brake
System (ABS)
The Antilock Brake System (ABS)
helps prevent a braking skid and
maintain steering while braking hard.
ABS performs a system check when
the vehicle is first driven.
A momentary motor or clicking noisemay be heard while this test is going
on, and the brake pedal may move
slightly. This is normal.
If there is a problem with ABS, this
warning light stays on. See
Antilock
Brake System (ABS) Warning Light
0 126.
ABS does not change the time needed
to get a foot on the brake pedal and
does not always decrease stopping
distance. If you get too close to the
vehicle ahead, there will not be
enough time to apply the brakes if
that vehicle suddenly slows or stops.
Always leave enough room ahead to
stop, even with ABS.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/14/19
200 DRIVING AND OPERATING
Using ABS
Do not pump the brakes. Just hold the
brake pedal down firmly and let ABS
work. You may hear the ABS pump or
motor operating and feel the brake
pedal pulsate. This is normal.
When ABS is active, it may be an
indication that road surfaces are
slippery. Braking sooner may be
required for driving conditions.
If equipped with electric brake boost,
the TCS/StabiliTrak/ESC light will
flash when ABS is active.
Braking in Emergencies
ABS allows steering and braking at the
same time. In many emergencies,
steering can help even more than
braking.
Electric Parking Brake
The vehicle has an Electric Parking
Brake (EPB). The EPB can always be
activated, even if the ignition is off. To
prevent draining the battery, avoid
repeated cycles of the EPB system
when the engine is not running.
The system has a
Yor PARK
Electric Parking Brake light, and a
8
Service Parking Brake light. See
Electric Parking Brake Light 0125 and
Service Electric Parking Brake Light
0 126. Before leaving the vehicle, check for
the
Yor PARK light to ensure that
the parking brake is applied.
EPB Apply
To apply the EPB:
1. Be sure the vehicle is at a complete stop.
2. Press the EPB switch momentarily.
The
Yor PARK light will flash and
then stay on once the EPB is fully
applied. If the
Yor PARK light
flashes continuously, then the EPB is
only partially applied or there is a
problem with the EPB. A DIC message
will display. Release the EPB and try
to apply it again. If the light does not
come on, or keeps flashing, have the
vehicle serviced. Do not drive the
vehicle if the
Yor PARK light is
flashing. See your dealer. See Electric
Parking Brake Light 0125.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/14/19
DRIVING AND OPERATING 203
Ride Control Systems
Traction Control/Electronic
Stability Control
System Operation
The vehicle has a Traction Control
System (TCS) and StabiliTrak/
Electronic Stability Control (ESC).
These systems help limit wheel spin
and assist the driver in maintaining
control, especially on slippery road
conditions.
TCS activates if it senses that any of
the drive wheels are spinning or
beginning to lose traction. When this
happens, TCS applies the brakes to the
spinning wheels and reduces engine
power to limit wheel spin.
StabiliTrak/ESC activates when the
vehicle senses a difference between
the intended path and the direction
the vehicle is actually traveling.
StabiliTrak/ESC selectively applies
braking pressure to any one of the
vehicle wheel brakes to assist the
driver in keeping the vehicle on the
intended path.If cruise control is being used and
traction control or StabiliTrak/ESC
begins to limit wheel spin, cruise
control will disengage. Cruise control
may be turned back on when road
conditions allow.
Both systems come on automatically
when the vehicle is started and begins
to move. The systems may be heard or
felt while they are operating or while
performing diagnostic checks. This is
normal and does not mean there is a
problem with the vehicle.
It is recommended to leave both
systems on for normal driving
conditions, but it may be necessary to
turn TCS off if the vehicle gets stuck
in sand, mud, ice, or snow. See
If the
Vehicle Is Stuck 0179 and “Turning
the Systems Off and On ”later in this
section.
The indicator light for both systems is
in the instrument cluster. This
light will:
. Flash when TCS is limiting
wheel spin.
. Flash when StabiliTrak/ESC is
activated.
. Turn on and stay on when either
system is not working.
If either system fails to turn on or to
activate, a message displays in the
Driver Information Center (DIC), and
dcomes on and stays on to indicate
that the system is inactive and is not
assisting the driver in maintaining
control. The vehicle is safe to drive,
but driving should be adjusted
accordingly.
If
dcomes on and stays on:
1. Stop the vehicle.
2. Turn the engine off and wait 15 seconds.
3. Start the engine.
4. Drive the vehicle.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/14/19
DRIVING AND OPERATING 205
The Driver Mode Control has multiple
modes: Tour, Sport, Snow/Ice, and
Track. The Track Mode is available for
V-Series models only. All modes have
preset vehicle settings for use in
different driving conditions. For
further detail see“Mode Description ”.
To activate a mode, press
yorzon
the MODE switch to make a mode
selection in the instrument cluster.
Every press will scroll to the next
available mode.
Mode Description
The following describes the modes
that can be selected in further detail.
Tour Mode
Use for normal city and highway
driving to provide a smooth, soft ride.
This setting provides a balanced
setting between comfort and handling.
This is the standard mode. For further
details on Tour Mode, see “Driver
Mode Selector Attributes Affected ”.
Sport Mode
Use where road conditions or personal
preference demand a more controlled
response.
When selected, the Sport Mode
indicator light will display in the
instrument cluster.
In this mode, the vehicle monitors
driving behaviors and automatically
enables Performance Shift Features
when spirited driving is detected.
These features maintain lower
transmission gears to increase
available engine braking and improve
acceleration response. The vehicle will exit these features and return to
normal operation after a short period
when no spirited driving is detected.
The steering including Active Rear
Steer (if equipped), will change to
provide more precise control. If the
vehicle has Magnetic Ride Control, the
suspension will change to provide
better cornering performance. If the
vehicle is equipped with AWD, Sport
Mode sends more torque to the rear
wheels.
For further details on Sport Mode, see
“Driver Mode Selector Attributes
Affected”.
Snow/Ice Mode
Snow/Ice Mode is used for slippery
surfaces to help control wheel speed.
This can compromise the acceleration
on dry asphalt. Snow/Ice Mode will
use a different accelerator pedal map
to optimize traction on a slippery
surface. The accelerator pedal will
reduce engine torque at small pedal
inputs.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/14/19
DRIVING AND OPERATING 207
Driver Mode Selector Attributes Affected
The different modes features are shown below. Not all vehicles have all features, depending on the vehicle options.Modes: TOUR DefaultSPORT TRACK SNOW/ICE
Throttle Progression Tour Tour Track Snow/Ice
Transmission Shift Mode Tour Sport Track Tour
Engine Sound Tour Sport Track Tour
Steering Tour Sport Track Tour
Suspension (if equipped with Magnetic Ride) Tour Sport Track Tour
Traction and Stability Control Tour Tour Track Tour
Throttle Progression
Adjusts throttle sensitivity by
selecting how quick or slow the
throttle reacts to input.
. Snow/Ice - The accelerator pedal
will reduce engine torque at small
pedal inputs. This allows better
wheel control on slippery surfaces.
. Track - The accelerator pedal is
adjusted to give maximum control
during the highest level of spirited
driving. Transmission Shift Mode
Sport or Track
–Performance Shift
Features are enabled in Sport and
Track. Performance Shift Features
include Performance Algorithm
Liftfoot and Performance Algorithm
Shift. Performance Algorithm Liftfoot
(PAL) allows the transmission to hold
the current gear after a quick release
of a heavily applied accelerator pedal.
This provides greater engine braking
and enhanced vehicle control without
using the paddles. Performance Algorithm Shift (PAS) recognizes
aggressive cornering, heavy braking,
and high acceleration to select and
hold lower gears when not using
paddles.
When PAL/PAS is activated, there is
an additional green gear symbol which
appears in the instrument cluster
display. See
Gear Shifting Light 0126.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/14/19
208 DRIVING AND OPERATING
Engine Sound
Adjusts the volume of engine noise
from quietest in Tour mode to most
robust in Track mode.
Steering
Adjusts from a lighter steering feel in
Tour Mode to reduced assist in Sport
and Track Mode for more
steering feel.
Suspension (if equipped with
Magnetic Ride)
Adjusts the shock dampening
firmness from a comfort tune in Tour
Mode to an optimized responsiveness
tune in Sport and Track.
Traction and Stability Control
StabiliTrak/Electronic Stability Control
(ESC) can be turned off by pressing
and holding the button for
five seconds.
Driver Mode Customization
The Engine Sound Management,
steering, and suspension drive modes
can be set to the driver’s preference.
See“Driving Mode ”under Vehicle
Personalization 0140. When in the Track main vehicle mode,
you cannot overwrite the Steering or
Suspension settings. These settings
are designed to interact with the
advanced functions in the Track Mode
and cannot be overwritten.
The selections made in the Driving
Mode menu overwrite the main
vehicle mode selection via the buttons
or switch on the center console. In
order to customize and overwrite,
select one of the three settings by
touching the infotainment display.
When in the customization screen for
each system, select one of the
available options:
•
Auto (Follows the MODE switch)
• Tour
• Sport
• Track (V-Series only) The default will be to follow the
vehicle MODE switch settings, but the
main vehicle mode selection for the
currently selected system can be
overwritten using this menu. The
settings selected in this menu will set
the vehicle behavior in all selected
vehicle modes, and will be retained
over each ignition cycle. They do not
have to be reset each time the vehicle
is started.
Locking Rear Axle
Vehicles with a limited-slip rear axle
can give more traction on snow, mud,
ice, sand, or gravel. When traction is
low, this feature allows the drive
wheel with the most traction to move
the vehicle. The limited-slip rear axle
also gives the driver enhanced control
when cornering hard or completing a
maneuver, such as a lane change. For
vehicles with limited-slip rear axle, the
rear axle fluid should be changed. See
Maintenance Schedule
0359.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/14/19
258 DRIVING AND OPERATING
Other files should not be stored on
the same SD card as the surround
vision recorder files. Storing other files
on the same card may increase
recording start up and playback time
or result in a loss of data. An error
message may be displayed if no
surround vision recorded video file is
available for playback.Fuel
Top Tier Fuel
GM recommends the use of TOP TIER
Detergent Gasoline to keep the engine
clean, reduce engine deposits, and
maintain optimal vehicle performance.
Look for the TOP TIER Logo or see
www.toptiergas.com for a list of TOP
TIER Detergent Gasoline marketers
and applicable countries.
Recommended Fuel (3.6L
V6 Engine)
Use regular unleaded gasoline meeting
ASTM specification D4814 with a
posted octane rating of 87—(R+M)/2
— or higher. Do not use gasoline with
a posted octane rating of less than 87,
as this may cause engine knock and
will lower fuel economy.
Do not use any fuel labeled E85 or
FlexFuel. Do not use gasoline with
ethanol levels greater than 15% by
volume.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/14/19
DRIVING AND OPERATING 259
Recommended Fuel (4.2L
Twin Turbo V8 Engine)
Use premium unleaded gasoline
meeting ASTM specification D4814
with a posted octane rating of 93—
(R+M)/2. If unavailable, unleaded
gasoline with a posted octane rating
of 91 may be used, but with reduced
performance and fuel economy. If the
octane is less than 91, the engine
could be damaged and the repairs
would not be covered by the vehicle
warranty. If heavy knocking is heard
when using gasoline rated at
93 octane, the engine needs service.
Do not use any fuel labeled E85 or
FlexFuel. Do not use gasoline with
ethanol levels greater than 15% by
volume.
Prohibited Fuels
Caution
Do not use fuels with any of the
following conditions; doing so may
damage the vehicle and void its
warranty:
. For vehicles that are not
FlexFuel, fuel labeled greater
than 15% ethanol by volume,
such as mid-level ethanol
blends (16–50% ethanol), E85,
or FlexFuel.
. Fuel with any amount of
methanol, methylal, ferrocene,
and aniline. These fuels can
corrode metal fuel system
parts or damage plastic and
rubber parts.
. Fuel containing metals such
as methylcyclopentadienyl
manganese tricarbonyl
(MMT), which can damage
the emissions control system
and spark plugs.
(Continued)
Caution (Continued)
.Fuel with a posted octane
rating of less than the
recommended fuel. Using this
fuel will lower fuel economy
and performance, and may
decrease the life of the
emissions catalyst.
Fuels in Foreign Countries
The U.S., Canada, and Mexico post
fuel octane ratings in anti-knock index
(AKI). For fuel not to use in a foreign
country, see Prohibited Fuels 0259.
Fuel Additives
TOP TIER Detergent Gasoline is highly
recommended for use with your
vehicle. If your country does not have
TOP TIER Detergent Gasoline, add
ACDelco Fuel System Treatment Plus
−Gasoline to the vehicle’s gasoline fuel
tank at every oil change or 15 000 km
(9,000 mi), whichever occurs first. TOP
TIER Detergent Gasoline and ACDelco
Fuel System Treatment Plus−Gasoline