2021 CADILLAC XT6 check engine

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
DRIVING AND OPERATING 225
Traction is reduced on hard packed
snow and ice and it is easy to lose
control. Reduce vehicle speed when
driving on hard packed snow and ice.
{Warning
Driving on frozen lakes, ponds,
or rivers can be dangerous. Ice
conditions vary greatly and the
vehicle could fall through the ice;
you and your passengers could
drown. Drive your vehicle on safe
surfaces only.
Driving in Water
{Warning
Driving through rushing water can
be dangerous. Deep water can
sweep your vehicle downstream and
you and your passengers could
drown. If it is only shallow water, it
can still wash away the ground
from under your tires. Traction
could be lost, and the vehicle could
roll over. Do not drive through
rushing water.
Caution
Do not drive through standing
water if it is deep enough to cover
the wheel hubs, axles, or exhaust
pipe. Deep water can damage the
axle and other vehicle parts.
If the standing water is not too deep,
drive slowly through it. At faster
speeds, water splashes on the ignition
system and the vehicle can stall.
Stalling can also occur if you get the
exhaust pipe under water. While the
exhaust pipe is under water, you will
not be able to start the engine. When
going through water, the brakes get
wet, and it might take longer to stop.
See Driving on Wet Roads 0225.
After Off-Road Driving
Remove any brush or debris that has
collected on the underbody or chassis,
or under the hood. These
accumulations can be a fire hazard.
After operation in mud or sand, have
the brake linings cleaned and checked.
These substances can cause glazing
and uneven braking. Check the body
structure, steering, suspension, wheels, tires, and exhaust system for
damage and check the fuel lines and
cooling system for any leakage.
Driving on Wet Roads
Rain and wet roads can reduce vehicle
traction and affect your ability to stop
and accelerate. Always drive slower in
these types of driving conditions and
avoid driving through large puddles
and deep-standing or flowing water.
{Warning
Wet brakes can cause crashes. They
might not work as well in a quick
stop and could cause pulling to one
side. You could lose control of the
vehicle.
After driving through a large puddle
of water or a car/vehicle wash,
lightly apply the brake pedal until
the brakes work normally.
Flowing or rushing water creates
strong forces. Driving through
flowing water could cause the
vehicle to be carried away. If this
happens, you and other vehicle
(Continued)

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
226 DRIVING AND OPERATING
Warning (Continued)
occupants could drown. Do not
ignore police warnings and be very
cautious about trying to drive
through flowing water.
Hydroplaning
Hydroplaning is dangerous. Water can
build up under the vehicle's tires so
they actually ride on the water. This
can happen if the road is wet enough
and you are going fast enough. When
the vehicle is hydroplaning, it has
little or no contact with the road.
There is no hard and fast rule about
hydroplaning. The best advice is to
slow down when the road is wet.
Other Rainy Weather Tips
Besides slowing down, other wet
weather driving tips include:
.Allow extra following distance.
.Pass with caution.
.Keep windshield wiping equipment
in good shape.
.Keep the windshield washer fluid
reservoir filled.
.Have good tires with proper tread
depth. SeeTires0337.
.Turn off cruise control.
Hill and Mountain Roads
Driving on steep hills or through
mountains is different than driving on
flat or rolling terrain. Tips include:
.Keep the vehicle serviced and in
good shape.
.Check all fluid levels and brakes,
tires, cooling system, and
transmission.
.Shift to a lower gear when going
down steep or long hills.
{Warning
Using the brakes to slow the vehicle
on a long downhill slope can cause
brake overheating, can reduce brake
performance, and could result in a
loss of braking. Shift the
transmission to a lower gear to let
the engine assist the brakes on a
steep downhill slope.
{Warning
Coasting downhill in N (Neutral) or
with the ignition off is dangerous.
This can cause overheating of the
brakes and loss of steering assist.
Always have the engine running
and the vehicle in gear.
.Drive at speeds that keep the
vehicle in its own lane. Do not
swing wide or cross the center line.
.Be alert on top of hills; something
could be in your lane (e.g., stalled
car, crash).
.Pay attention to special road signs
(e.g., falling rocks area, winding
roads, long grades, passing or
no-passing zones) and take
appropriate action.
Winter Driving
Driving on Snow or Ice
Snow or ice between the tires and the
road creates less traction or grip, so
drive carefully. Wet ice can occur at
about 0 °C (32 °F) when freezing rain

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
236 DRIVING AND OPERATING
starting the vehicle. An internal
thermostat in the plug end of the cord
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. Remove the engine heater
connector cover by gently prying
with a flat-bladed tool at the
location of the notch along the top
edge of the cover.
3. 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.
4. Plug the heater cord into theconnector in the front fascia.
5. 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
(Continued)

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
238 DRIVING AND OPERATING
Warning (Continued)
move suddenly. You or others could
be injured. To be sure the vehicle
will not move, even when you are
on fairly level ground, always set
the parking brake and shift to
P (Park). SeeShifting Into Park 0237
. If you are towing a trailer, see
Driving Characteristics and Towing
Tips 0290.
If you have to leave the vehicle with
the engine running, be sure the
vehicle is in P (Park) and the parking
brake is set before you leave it.
If you are towing a trailer and parking
on a hill, see Driving Characteristics
and Towing Tips 0290.
Shifting out of Park
This vehicle is equipped with an
electronic transmission. The shift lock
release button is designed to prevent
inadvertent shifting out of P (Park).
To shift out of P (Park):
1. Ensure the engine is running.
2. Apply the brake pedal. 3. Press and hold the shift lock
release button on the shift lever.
4. Move the shift lever to the desired position. For N (Neutral) hold the
lever in the N (Neutral) position
until the N indicator
illuminates red.
5. The P indicator will turn white and the gear indicator will turn red
when the vehicle is no longer in
P (Park).
After releasing the shift lever, it will
return to the center position.
If the vehicle cannot shift from
P (Park), a Driver Information Center
(DIC) message may be displayed.
Check that the ignition is on, the
engine is running, the brake pedal is
applied, and the shift lock release
button is pressed when you are
attempting to shift out of P (park).
If all of these are met but the vehicle
will not shift out of P (Park), see your
dealer for 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.
Active Fuel Management
This vehicle's engine may be equipped
with Active Fuel Management, which
allows the engine to operate on either
all of its cylinders, or in reduced
cylinder operation mode, depending
on the driving conditions.
When less power is required, such as
cruising at a constant vehicle speed,
the system will operate in reduced
cylinder operation mode, allowing the
vehicle to achieve better fuel economy.
When greater power demands are
required, such as accelerating from a
stop, passing, or merging onto a
freeway, the system will maintain
full-cylinder operation.

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
DRIVING AND OPERATING 241
This vehicle is equipped with an
electronically controlled transmission.
The shift lock release button is
designed to prevent inadvertent
shifting out of P (Park) unless the
ignition is on, the brake pedal is
applied, and the shift lock release
button is pressed.
When the vehicle is stopped, press
ENGINE START/STOP to turn off the
vehicle. The transmission will shift to
P (Park) automatically unless the
vehicle is in N (Neutral), See“Car
Wash Mode ”later in this section.
The vehicle will not shift into P (Park)
if it is moving too fast. Stop the
vehicle and shift into P (Park). To shift into and out of P (Park), see
Shifting Into Park
0237 and
Shifting out of Park 0238.
Service Shift Lever Message
If the message SERVICE SHIFTER SEE
OWNER’S MANUAL appears in the
Driver Information Center (DIC), the
shift lever needs service. Have the
vehicle serviced as soon as possible.
If the vehicle is automatically shifting
into P (Park), check to see if the
P (Park) button on top of the shift
lever is stuck. To operate the vehicle,
hold the shift lever in the desired gear,
R (Reverse) or D (Drive), until vehicle
speed exceeds 15 km/h (10 mph), then
release the shift lever.
R : Use this gear to back up.
If the vehicle is shifted from either
R (Reverse) to D (Drive) or M (Manual
Mode), or M (Manual Mode) or
D (Drive) to R (Reverse) while the
speed is too high, the vehicle will shift
to N (Neutral). Reduce the vehicle
speed and try the shift again.
To shift into R (Reverse): 1. Bring the vehicle to a complete stop. 2. Press and hold the shift lock
release button on the side of the
shift lever.
3. From the center position, move the shift lever forward through the first
detent to the end of travel. R is
illuminated in red.
4. After releasing the shift lever, it will return to the center position.
To shift out of R (Reverse): 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.
At low vehicle speeds, R (Reverse) can
be used to rock the vehicle back and
forth to get out of snow, ice, or sand
without damaging the transmission.
See If the Vehicle Is Stuck 0228.
N : In this position, the engine does
not connect with the wheels. To
restart the engine when the vehicle is
already moving, use N (Neutral) only.

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) -
2021 - CRC - 2/8/21
DRIVING AND OPERATING 291
If equipped with Lane Change Alert
(LCA), the LCA detection zones that
extend back from the side of the
vehicle do not move further back
when a trailer is towed. Use caution
while changing lanes when towing a
trailer.
If equipped with Rear Cross Traffic
Alert (RCTA), use caution while
backing up when towing a trailer, as
the RCTA detection zones that extend
out from the back of the vehicle do
not move further back when a trailer
is towed.
{Warning
To prevent serious injury or death
from carbon monoxide (CO), when
towing a trailer:
.Do not drive with the liftgate,
trunk/hatch, or rear-most
window open.
.Fully open the air outlets on or
under the instrument panel.(Continued)
Warning (Continued)
.Adjust the climate control
system to a setting that brings in
only outside air. See“Climate
Control Systems” in the Index.
For more information about carbon
monoxide, see Engine Exhaust
0 239.
Towing a trailer requires experience.
The combination of the vehicle and
trailer is longer and not as responsive
as the vehicle itself. Get used to the
handling and braking of the
combination by driving on a level road
surface before driving on public roads.
The trailer structure, the tires, and the
brakes must be all be rated to carry
the intended cargo. Inadequate trailer
equipment can cause the combination
to operate in an unexpected or unsafe
manner. Before driving, inspect all
trailer hitch parts and attachments,
safety chains, electrical connectors,
lamps, tires, and mirrors. See Towing
Equipment 0297. If the trailer has
electric brakes, start the combination
moving and then manually apply the trailer brake controller to check the
trailer brakes work. During the trip,
occasionally check that the cargo and
trailer are secure and that the lamps
and any trailer brakes are working.
Towing with a Stability Control
System
When towing, the stability control
system might be heard. The system
reacts to vehicle movement caused by
the trailer, which mainly occurs
during cornering. This is normal when
towing heavier trailers.
Following Distance
Stay at least twice as far behind the
vehicle ahead as you would when
driving without a trailer. This can help
to avoid heavy braking and sudden
turns.
Passing
More passing distance is needed when
towing a trailer. The combination of
the vehicle and trailer will not
accelerate as quickly and is much
longer than the vehicle alone. It is
necessary to go much farther beyond

Cadillac XT6 Owner Manual (GMNA-Localizing-U.S./Canada-14574701) -
2021 - CRC - 2/8/21
DRIVING AND OPERATING 293
.Shift into a gear.
.Release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
Maintenance When Trailer
Towing
The vehicle needs service more often
when used to tow trailers. See
Maintenance Schedule 0380. It is
especially important to check the
transmission for fluid leaks, engine
oil, axle lubricant, belts, cooling
system, and brake system before and
during each trip.
Check periodically that all nuts and
bolts on the trailer hitch are tight.
Engine Cooling When Trailer
Towing
The cooling system may temporarily
overheat during severe operating
conditions. See Engine Overheating
0 320.
Trailer Towing
Caution
Towing a trailer improperly can
damage the vehicle and result in
costly repairs not covered by the
vehicle warranty. To tow a trailer
correctly, follow the directions in
this section and see your dealer for
important information about
towing a trailer with the vehicle.
Trailer Weight
{Warning
Never exceed the towing capacity
for your vehicle.
Safe trailering requires monitoring the
weight, speed, altitude, road grades,
outside temperature, dimensions of
the front of the trailer, and how
frequently the vehicle is used to tow a
trailer.
Trailer Weight Ratings
When towing a trailer, the combined
weight of the vehicle, vehicle contents,
trailer, and trailer contents must be
below all of the maximum weight
ratings for the vehicle including:
.GCWR: Gross Combined Weight
Rating
.GVWR: Gross Vehicle Weight Rating
.Maximum Trailer Weight Rating
.Maximum Trailer Tongue Weight
See “Weight-Distributing Hitch
Adjustment ”under Towing Equipment
0 297 to determine if equalizer bars
are required to obtain the maximum
trailer weight rating.
See “Trailer Brakes ”under Towing
Equipment 0297 to determine if
brakes are required based on your
trailer's weight.
The only way to be sure the weight is
not exceeding any of these ratings is
to weigh the tow vehicle and trailer
combination, fully loaded for the trip,
getting individual weights for each of
these items.