engine CADILLAC XT6 2021 Repair Manual

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
242 DRIVING AND OPERATING
{Warning
Shifting into a drive gear while the
engine is running at high speed is
dangerous. Unless your foot is
firmly on the brake pedal, the
vehicle could move very rapidly.
You could lose control and hit
people or objects. Do not shift into
a drive gear while the engine is
running at high speed.
Caution
Shifting out of P (Park) or
N (Neutral) with the engine running
at high speed may damage the
transmission. The repairs would not
be covered by the vehicle warranty.
Be sure the engine is not running at
high speed when shifting the
vehicle.
The vehicle is not designed to stay in
N (Neutral) for more than
five minutes. It may automatically
shift into P (Park). N (Neutral) is not intended for towing. If the vehicle
needs to be towed, see
Towing the
Vehicle 0367.
To shift into N (Neutral): 1. Move the shift lever forward to the first detent from the center
position.
.If the vehicle is in P (Park),
apply the brake pedal and press
the shift lock release button
while moving the shift lever
forward.
.N will illuminate in red.
2. After releasing the shift lever, it will return to the center position.
To shift out of N (Neutral): 1. Bring the vehicle to a complete stop.
2. Shift to the desired gear. If shifting from N (Neutral) to R (Reverse),
press the shift lock release button.
3. After releasing the shift lever, it will return to the center position.
Car Wash Mode
This vehicle includes a Car Wash
Mode that allows the vehicle to
remain in N (Neutral) for use in
automatic car washes.
Car Wash Mode (Engine Off –Driver
in Vehicle)
To place the vehicle in N (Neutral)
with the engine off and the vehicle
occupied:
1. Drive to the entrance of the car wash.
2. Apply the brake pedal.
3. Shift to N (Neutral).
4. Turn off the engine and release the brake pedal.
5. The indicator should continue to show N. If it does not, repeat
Steps 2–4.
6. The vehicle is now ready for the car wash.

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
DRIVING AND OPERATING 243
Car Wash Mode (Engine Off–Driver
out of Vehicle)
To place the vehicle in N (Neutral)
with the engine off and the vehicle
unoccupied:
1. Drive to the entrance of the car wash.
2. Apply the brake pedal.
3. Open the door.
4. Shift to N (Neutral).
5. Turn off the engine and release the brake pedal.
6. The indicator should continue to show N. If it does not, repeat
Steps 2–5.
7. Exit the vehicle and close the door. The vehicle is now ready for the
car wash.
8. The vehicle may automatically shift to P (Park) when the door is
opened. Car Wash Mode (Engine On
–Driver
in Vehicle)
To place the vehicle in N (Neutral)
with the engine on and the vehicle
occupied:
1. Drive to the entrance of the car wash.
2. Apply the brake pedal.
3. Shift to N (Neutral).
4. Release the brake pedal. The vehicle is now ready for the
car wash.
Car Wash Mode (Engine On –Driver
out of Vehicle)
To place the vehicle in N (Neutral)
with the engine on and the vehicle
unoccupied:
1. Drive to the entrance of the car wash.
2. Apply the brake pedal.
3. Open the door.
4. Shift to N (Neutral), then release the brake pedal.
5. The indicator should continue to show N. If it does not, repeat
Steps 2–4. 6. Exit the vehicle and close the door.
The vehicle is now ready for the
car wash.
7. The vehicle may automatically shift to P (Park) when the door is
opened.
Caution
A transmission hot message may
display if the automatic
transmission fluid is too hot.
Driving under this condition can
damage the vehicle. Stop and idle
the engine to cool the automatic
transmission fluid. This message
clears when the transmission fluid
has cooled sufficiently.
D : This position is for normal driving.
If more power is needed for passing,
press the accelerator pedal down.
To shift into D (Drive):
1. Bring the vehicle to a complete stop.

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
244 DRIVING AND OPERATING
2. From the center position, move theshift 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 0221.
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.
If equipped, vehicles with Tap Shift
have controls on the back of the
steering wheel to manually shift the
automatic transmission.
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.

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
DRIVING AND OPERATING 245
3. Pull the control toward you toshift. Pull the left control to
downshift, and the right control to
upshift.
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) prior to shifting back to
D (Drive).
Temporary Tap 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 Shift
Mode, allowing the transmission to
be manually shifted. 2. 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, the M or D
will flash 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.
Drive Systems
All-Wheel Drive
Vehicles with this feature can operate
in All-Wheel Drive (AWD) Mode. See
Driver Mode Control 0250.
Press MODE to activate AWD. AWD is
active in both AWD and Sport Modes.
The AWD system delivers power to all
four wheels and the system adjusts as
needed to improve traction.
The AWD Mode will stay selected
until the mode is changed. If the
vehicle is placed in Sport Mode, see
Driver Mode Control 0250.
Sport Mode is canceled with each
ignition cycle. See Driver Mode Control
0 250.
When operated in Tour Mode, the
vehicle will deliver power to the front
wheels only and may provide better
fuel economy.

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
248 DRIVING AND OPERATING
If you are towing a trailer and parking
on a hill, seeDriving Characteristics
and Towing Tips 0290.
Automatic EPB Release
The EPB will automatically release if
the vehicle is running, placed into
gear, and an attempt is made to drive
away. Avoid rapid acceleration when
the EPB is applied, to preserve parking
brake lining life.
Brake Assist
Brake Assist detects rapid brake pedal
applications due to emergency braking
situations and provides additional
braking to activate the Antilock Brake
System (ABS) if the brake pedal is not
pushed hard enough to activate ABS
normally. Minor noise, brake pedal
pulsation, and/or pedal movement
during this time may occur. Continue
to apply the brake pedal as the driving
situation dictates. Brake Assist
disengages when the brake pedal is
released.
Hill Start Assist (HSA)
{Warning
Do not rely on the HSA feature.
HSA does not replace the need to
pay attention and drive safely. You
may not hear or feel alerts or
warnings provided by this system.
Failure to use proper care when
driving may result in injury, death,
or vehicle damage. See Defensive
Driving 0219.
When the vehicle is stopped on a
grade, Hill Start Assist (HSA) prevents
the vehicle from rolling in an
unintended direction during the
transition from brake pedal release to
accelerator pedal apply. The brakes
release when the accelerator pedal is
applied. If the accelerator pedal is not
applied within a few minutes, the
Electric Parking Brake will apply. The
brakes may also release under other
conditions. Do not rely on HSA to
hold the vehicle.
HSA is available when the vehicle is
facing uphill in a forward gear,
or when facing downhill in R (Reverse). The vehicle must come to
a complete stop on a grade for HSA to
activate.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. On an
All-Wheel Drive (AWD) vehicle in
AWD or Sport Mode, the system will
operate if it senses that any of the
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.

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
DRIVING AND OPERATING 249
StabiliTrak/ESC activates when the
system senses a discrepancy between
the intended path and the direction
the vehicle is actually traveling.
StabiliTrak/ESC selectively applies
braking pressure at any one of the
vehicle's brakes to help steer the
vehicle in the direction which you are
steering.
If cruise control is being used and TCS
or StabiliTrak/ESC begins to limit
wheel spin, cruise control will
disengage. Cruise control may be
turned back on when road conditions
allow. TCS and StabiliTrak/ESC will
automatically turn on when cruise
control is set.
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 stuckin sand, mud, ice, or snow. See
If the
Vehicle Is Stuck 0228 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 may display 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.
Drive the vehicle. If
dcomes on and
stays on, the vehicle may need more
time to diagnose the problem. If the
condition persists, see your dealer.
Turning the Systems Off and On

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
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DRIVING AND OPERATING 251
displayed in the instrument cluster.
For more information on AWD Mode,
seeAll-Wheel Drive 0245.
Mode Descriptions
Tour : Tour Mode operates in FWD to
improve fuel economy. This setting
provides balance between comfort and
handling. This is the standard/default
mode and should be used during
normal driving operations. There is no
persistent indicator in the instrument
cluster for this mode.
Sport : Sport Mode improves vehicle
handling and acceleration on dry
pavement. When active, Sport Mode
modifies steering efforts, transmission
shifting, AWD torque, and suspension
tuning (if equipped). Choosing Sport
Mode also engages AWD (if equipped).
The Performance Algorithm Liftfoot
(PAL) feature is enabled in Sport
Mode. 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. When PAL is activated, there may be
an additional green gear symbol which
appears in the instrument cluster
display. See
Performance Shifting Light
0 119.
AWD : AWD Mode provides drive
torque to all four wheels. Select AWD
to improve traction and control on
slippery road surfaces, such as gravel,
sand, wet pavement, snow, and ice For
more information on AWD Mode, see
All-Wheel Drive 0245.
Snow/Ice (FWD Vehicles Only) :
Snow/Ice Mode improves vehicle
acceleration on snow and ice covered
roads. This mode will adjust
acceleration to optimize traction on a
slippery surface. The accelerator pedal
will reduce engine torque at small
pedal inputs.
Off-Road : Use this mode for off-road
recreational driving. When active,
Off-Road Mode modifies accelerator
pedal response, AWD torque, TCS,
ABS and ESC settings. Choosing
Off-Road Mode also engages AWD.
Cruise Control
{
Warning
Cruise control can be dangerous
where you cannot drive safely at a
steady speed. Do not use cruise
control on winding roads or in
heavy traffic.
Cruise control can be dangerous on
slippery roads. On such roads, fast
changes in tire traction can cause
excessive wheel slip, and you could
lose control. Do not use cruise
control on slippery roads.
With cruise control, a speed of about
40 km/h (25 mph) or more can be
maintained without keeping your foot
on the accelerator. Cruise control does
not work at speeds below about
40 km/h (25 mph).
If the Traction Control System (TCS)
or StabiliTrak/Electronic Stability
Control (ESC) system begins to limit
wheel spin while using cruise control,
cruise control automatically
disengages. See Traction Control/
Electronic Stability Control 0248. If a

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
286 DRIVING AND OPERATING
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 (2.0L
L4 Turbo Engine)
Premium unleaded gasoline meeting
ASTM specification D4814 with a
posted octane rating of 93—(R+M)/2
— is highly recommended for best
performance and fuel economy.
Unleaded gasoline with an octane
rated as low as 87 can be used. Using
unleaded gasoline rated below
93 octane, however, will lead to
reduced acceleration and fuel
economy. If knocking occurs, use a
gasoline rated at 93 octane as soon as
possible, otherwise, the engine could
be damaged. If heavy knocking is
heard when using gasoline with a
93 octane rating, 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.
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.

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DRIVING AND OPERATING 287
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.
.Fuel with a posted octane rating
of less than the recommended
fuel. Using this fuel will lower(Continued)
Caution (Continued)
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, seeProhibited Fuels 0287.
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
will help keep your vehicle’s engine
fuel deposit free and performing
optimally.
Filling the Tank
An arrow on the fuel gauge indicates
which side of the vehicle the fuel door
is on. See Fuel Gauge 0112.
{Warning
Fuel vapors and fuel fires burn
violently and can cause injury or
death.
Follow these guidelines to help
avoid injuries to you and others:
.Read and follow all the
instructions on the fuel pump
island.
.Turn off the engine when
refueling.
.Keep sparks, flames, and
smoking materials away
from fuel.
.Do not leave the fuel pump
unattended.
.Avoid using electronic devices
while refueling.
(Continued)

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
288 DRIVING AND OPERATING
Warning (Continued)
.Do not re-enter the vehicle while
pumping fuel.
.Keep children away from the fuel
pump and never let children
pump fuel.
.Before touching the fill nozzle,
touch a metallic object to
discharge static electricity from
your body.
.Fuel can spray out if the fill
nozzle is inserted too quickly.
This spray can happen if the
tank is nearly full, and is more
likely in hot weather. Insert the
fill nozzle slowly and wait for any
hiss noise to stop before
beginning to flow fuel.To open the fuel door, push and
release the rearward center edge of
the door.
The capless refueling system does not
have a fuel cap. Fully insert and latch
the fill nozzle, then begin fueling.
{Warning
Overfilling the fuel tank by more
than three clicks of a standard fill
nozzle may cause:
.Vehicle performance issues,
including engine stalling and
damage to the fuel system.(Continued)
Warning (Continued)
.Fuel spills.
.Under certain conditions, fuel
fires.
Be careful not to spill fuel. Wait
five seconds after you have finished
pumping before removing the fill
nozzle. Clean fuel from painted
surfaces as soon as possible. See
Exterior Care 0370. Push the fuel door
closed until it latches.
{Warning
If a fire starts while you are
refueling, do not remove the fill
nozzle. Shut off the flow of fuel by
shutting off the pump or by
notifying the station attendant.
Leave the area immediately.