2018 CADILLAC CT6 engine

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
222 DRIVING AND OPERATING
too much gasoline. Try pushing
the accelerator pedal all the way
to the floor and holding it there
as you press ENGINE START/
STOP. Wait at least 15 seconds
between each try, to allow the
cranking motor to cool down.
When the engine starts, release
the accelerator. If the vehicle
starts briefly but then stops
again, do the same thing. This
clears the extra gasoline from the
engine. Do not race the engine
immediately after starting it.
Operate the engine and
transmission gently until the oil
warms up and lubricates all
moving parts.
Stop/Start System
{Warning
Exiting the vehicle without first
shifting into P (Park) may cause the
vehicle to move. You or others may
be injured. Because the vehicle may
have an auto engine stop/start
feature, the vehicle's engine might(Continued)
Warning (Continued)
seem to be shut off; however, once
the brake pedal is released, the
engine will start up again.
Shift to P (Park) and turn the
ignition off before exiting the
vehicle.
The vehicle has a fuel saving stop/
start system to shut off the engine
and help conserve fuel.
Auto Engine Stop/Start
When the brakes are applied and the
vehicle is at a complete stop, the
engine may turn off. When stopped,
the tachometer may display Auto
Stop, or the Auto Stop light may come
on in the instrument cluster.
See Tachometer 0134 and Auto Stop
Mode (Uplevel Cluster) 0150. When the
brake pedal is released or the
accelerator pedal is pressed, the
engine may restart.
Auto Stop may be deactivated if:
. A minimum vehicle speed is not
reached. .
The engine or transmission is not
at the required operating
temperature.
. The outside temperature is not in
the required operating range,
typically between -10 °C (14 °F)
and 50 °C (122 °F).
. The shift lever is in any gear other
than D (Drive).
. The battery has been recently
disconnected.
. The battery charge is low.
. The interior comfort level has not
reached the required level for the
climate control system or defog
settings.
See Automatic Climate Control
System (Quad Zone - Gasoline Only)
0 197 orAutomatic Climate Control
System (Dual Zone - Gasoline and
PLUG-IN) 0191.
. The Auto Stop time is greater than
two minutes.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
DRIVING AND OPERATING 223
The automatic engine stop/start
function can be disabled by
touching
hon the center stack.
When
hcomes on green in the
instrument cluster, the system is
active. The system is not active when
it comes on white with a slash
through it.
Engine Heater
Vehicles with the engine heater can
use this option in cold weather
conditions at or below −18 °C (0 °F) for
easier starting and better fuel
economy during engine warm-up. Plug
in the coolant heater at least four hours before starting your vehicle. An
internal thermostat in the plug-end of
the cord may exist which will prevent
engine heater operation at
temperatures above
−18 °C (0 °F).
{Warning
Do not plug in the engine block
heater while the vehicle is parked in
a garage or under a carport.
Property damage or personal injury
may result. Always park the vehicle
in a clear open area away from
buildings or structures.
To Use the Engine Heater
1. Turn off the engine.
2. Open the hood and unwrap the
electrical cord. The cord is
clipped to the diagonal brace on
the passenger side of the engine
compartment.
Check the heater cord for
damage. If it is damaged, do not
use it. See your dealer for a
replacement. Inspect the cord for
damage yearly. 3. Plug it into a normal, grounded
110-volt AC outlet.
{Warning
Improper use of the heater cord or
an extension cord can damage the
cord and may result in overheating
and fire.
. Plug the cord into a
three-prong electrical utility
receptacle that is protected by
a ground fault detection
function. An ungrounded
outlet could cause an electric
shock.
. Use a weatherproof,
heavy-duty, 15 amp-rated
extension cord if needed.
Failure to use the
recommended extension cord
in good operating condition,
or using a damaged heater or
extension cord, could make it
(Continued)

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
224 DRIVING AND OPERATING
Warning (Continued)
overheat and cause a fire,
property damage, electric
shock, and injury.
. Do not operate the vehicle
with the heater cord
permanently attached to the
vehicle. Possible heater cord
and thermostat damage could
occur.
. While in use, do not let the
heater cord touch vehicle
parts or sharp edges. Never
close the hood on the
heater cord.
. Before starting the vehicle,
unplug the cord, reattach the
cover to the plug, and
securely fasten the cord. Keep
the cord away from any
moving parts.
4. Before starting the engine, be sure to unplug and store the cord
as it was before to keep it away
from moving engine parts. If you
do not, it could be damaged. Contact your dealer for information
on how long to use the heater in your
particular area.
Retained Accessory
Power (RAP)
Some vehicle accessories may be used
after the ignition is turned off.
The power windows and sunroof,
if equipped, will continue to work for
up to 10 minutes or until any door is
opened.
The infotainment system will continue
to work for 10 minutes, until the
driver door is opened, or until the
ignition is turned on or placed in
ACC/ACCESSORY.
Shifting Into Park
To shift into P (Park):
1. Hold the brake pedal down and set the parking brake.
See Electric Parking Brake 0235. 2. Move the shift lever into P (Park)
by holding in the button on the
shift lever and pushing the lever
all the way toward the front of
the vehicle.
3. Turn the ignition off.
4. Take the Remote Keyless Entry (RKE) transmitter with you.
Leaving the Vehicle with the
Engine Running
{Warning
It can be dangerous to leave the
vehicle with the engine running.
It could overheat and catch fire.
It is dangerous to get out of the
vehicle if the shift lever is not fully
in P (Park) with the parking brake
firmly set. The vehicle can roll.
Do not leave the vehicle when the
engine is running. If you have left
the engine running, the vehicle can
move suddenly. You or others could
be injured. To be sure the vehicle
will not move, even when you are
(Continued)

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
DRIVING AND OPERATING 225
Warning (Continued)
on fairly level ground, always set
the parking brake and move the
shift lever to P (Park). SeeShifting
Into Park 0224. If you are towing a
trailer, see Driving Characteristics
and Towing Tips 0290.
If you have to leave the vehicle with
the engine running, the vehicle must
be in P (Park) and the parking brake
set. After shifting into P (Park), try to
move the shift lever out without first
pushing the button on the shift lever.
If you can, the shift lever was not
fully locked into P (Park).
Torque Lock
Torque lock is when the weight of the
vehicle puts too much force on the
parking pawl in the transmission. This
happens when parking on a hill and
shifting the transmission into P (Park)
is not done properly and then it is
difficult to shift out of P (Park). To
prevent torque lock, set the parking brake and then shift into P (Park). To
find out how, see "Shifting Into Park"
listed previously.
If torque lock does occur, the vehicle
may need to be pushed uphill by
another vehicle to relieve the parking
pawl pressure, so you can shift out of
P (Park).
Shifting out of Park
This vehicle is equipped with an
electronic shift lock release system.
The shift lock release is designed to
prevent movement of the shift lever
out of P (Park), unless the ignition is
on and the brake pedal is applied.
The shift lock release is always
functional except in the case of an
uncharged or low voltage (less than
9 volt) battery.
If the vehicle has an uncharged
battery or a battery with low voltage,
try charging or jump starting the
battery. See
Jump Starting - North
America 0374.
To shift out of P (Park): 1. Apply the brake pedal. 2. Release the parking brake. See
Electric Parking Brake 0235.
3. Press the shift lever button.
4. Move the shift lever.
If unable to shift out of P (Park): 1. Fully release the shift lever button.
2. While holding down the brake pedal, press the shift lever
button again.
3. Move the shift lever.
If the shift lever will not move from
P (Park), consult your dealer or a
professional towing service.
Parking over Things
That Burn
{Warning
Things that can burn could touch
hot exhaust parts under the vehicle
and ignite. Do not park over papers,
leaves, dry grass, or other things
that can burn.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
226 DRIVING AND OPERATING
Extended Parking
It is better not to park with the
vehicle running. If the vehicle is left
while running, follow the proper steps
to be sure the vehicle will not move
and there is adequate ventilation.
SeeShifting Into Park 0224 and Engine
Exhaust 0230.
If the vehicle is left parked while
running and the Remote Keyless
Entry (RKE) transmitter is outside the
vehicle, the vehicle will turn off after
one hour. If the vehicle is left parked
while running and the RKE
transmitter is inside, the vehicle will
turn off after two hours.
The timer will reset if the vehicle is
taken out of P (Park) while it is
running.
Electric Vehicle
Operating Modes
Driver Selected Operating
Modes (PLUG-IN Only)
For gasoline only engines see Driver
Mode Control (Gasoline Only) 0241.
While driving with PLUG-IN or
gasoline propulsion, additional
operating modes can be selected.
Press MODE to display selectable drive
modes in the Driver Information
Center (DIC). Continue pressing to
scroll through the modes. During some conditions, certain drive
modes may be unavailable. The
unavailable mode is grayed out in the
DIC menu and cannot be selected.
Tour
Mode
The vehicle is in Tour Mode when the
menu item Tour is selected. Use Tour
Mode whenever possible. Each time
the vehicle is started it will start in
Tour Mode.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
DRIVING AND OPERATING 227
SportMode
Sport Mode provides more responsive
acceleration than Tour Mode, but can
reduce efficiency. Use Tour Mode
whenever possible.
During some conditions, certain drive
modes may be unavailable. The
unavailable mode is grayed out in the
DIC menu and cannot be selected.
If in Sport or Hold Mode, the mode
may become unavailable and the
vehicle will return to Tour Mode. The
indicator light goes off and a DIC
message displays.
Press MODE to select Sport Mode. Press MODE again to return to Tour
Mode and it becomes active after
three seconds.
Hold
Mode
Use Hold Mode on a trip where it is
expected that all of the electric charge
will be depleted. Use Hold Mode
mainly during highway or high speed
driving to maximize both PLUG-IN
propulsion miles and fuel efficiency.
This mode places the remaining
battery charge into a reserve for the
driver to use as desired. Selecting this
mode transitions the vehicle to
gasoline propulsion to maintain the battery charge reserve. The reserve
battery charge will appear grayed out
while in this mode.
Upon exiting Hold Mode, the reserved
battery charge becomes available
again and the vehicle returns to
PLUG-IN propulsion.
Hold Mode will not change normal
vehicle acceleration or braking
performance.
Press MODE to select Hold Mode.
Press MODE again to return to Tour
Mode and it becomes active after
three seconds.
Out of Fuel/Engine
Unavailable
If the vehicle runs out of fuel, or the
engine will not start due to a
malfunction, the vehicle can continue
to be driven with electric propulsion
until the current charge is depleted.
The vehicle will have less responsive
acceleration. DIC messages indicate
reduced propulsion power, that the
engine is not available, and the need
for fuel or service.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
228 DRIVING AND OPERATING
Once the vehicle is refueled, or the
malfunction is corrected, the engine
will start the next time the vehicle is
turned on to perform a self test, and
DIC messages will not be displayed.
Once the engine starts successfully,
normal operation will continue with
either electric propulsion or with the
engine running. The engine will stop
running after the self test is
completed, and based on the current
mode of operation.
Maintenance Modes
Engine Maintenance Mode (EMM)
EMM runs the engine to keep it in
good working condition after
approximately six weeks of no or very
limited engine operation. EMM will
force the engine to run, even if there
is a charge to power the vehicle.
When EMM is needed, the EMM
Request screen appears on the
infotainment display at vehicle start.
If Yes is selected, EMM will begin. The
engine will not start until after a short
delay once shifted into D (Drive). The
engine will run for a set amount of
time without turning off. During
EMM, a DIC message displays to show
the EMM percentage complete.
If No is selected, the EMM Request
screen will appear when the vehicle is
next started. The EMM request can be
delayed for up to one day.
If the EMM request was delayed for
one day, EMM will automatically start
the engine at the next vehicle start.
The engine will not start until after a
short delay once shifted into D (Drive).An EMM Notification screen will
appear in the infotainment display.
If the vehicle is shut off during EMM,
it will restart the next time the vehicle
is driven.
A message displays to indicate that
EMM is active.
If EMM is required and the fuel level
is low, EMM may eventually empty
the fuel tank if fuel is not added. This

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
DRIVING AND OPERATING 229
will result in reduced, or no power. An
adequate fuel level must be
maintained in the vehicle to keep it
operational.
Fuel Maintenance Mode (FMM)
FMM tracks average fuel age. Old fuel
can cause engine problems. If low
engine usage causes average fuel age
to exceed approximately one year,
FMM will run the engine to use up
the old fuel. The engine will run until
enough fresh fuel is added to bring
the average fuel age into an
acceptable range. Allowing more old
fuel to be used up by FMM and
adding a larger amount of fresh fuel
will maximize the length of time
before another fuel maintenance
mode is needed. During FMM the
engine may turn on and off.
When FMM is needed, the FMM
Request screen appears on the
infotainment display at vehicle start.
If Yes is selected, FMM will begin. The
engine will not start until after a short
delay once shifted into D (Drive). FMM
will automatically continue at each
vehicle start until fresh fuel is added.
If No is selected, the FMM Request
screen will appear when the vehicle is
next started. The FMM request can be
delayed for only one day.If the FMM request was delayed for
one day, FMM will start at the next
vehicle start and display the FMM
Notification screen on the
infotainment display. The engine will
not start until after a short delay once
shifted into D (Drive).
If FMM is required and the fuel level
is low, FMM may eventually empty
the fuel tank if fuel is not added. This
will result in reduced, or no power. An
adequate fuel level must be
maintained in the vehicle to keep it
operational. After FMM has run it is
recommended to fill the fuel tank.