2020 CADILLAC CT6 check engine

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
264 DRIVING AND OPERATING
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
0 192.
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 0267. 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
the passed vehicle before returning to
the lane. Pass on level roadways.
Avoid passing on hills if possible.
Backing Up
Hold the bottom of the steering wheel
with one hand. To move the trailer to
the left, move that hand to the left. To
move the trailer to the right, move
that hand to the right. Always back up
slowly and, if possible, have someone
guide you.
Making Turns
Caution
Turn more slowly and make wider
arcs when towing a trailer to
prevent damage to your vehicle.
Making very sharp turns could
cause the trailer to contact the
vehicle.
Make wider turns than normal when
towing, so trailer will not go over soft
shoulders, over curbs, or strike road

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/14/19
DRIVING AND OPERATING 265
signs, trees, or other objects. Always
signal turns well in advance. Do not
steer or brake suddenly.
Driving on Grades
Reduce speed and shift to a lower gear
before starting down a long or steep
downhill grade. If the transmission is
not shifted down, the brakes may
overheat and result in reduced braking
efficiency.
Vehicles can tow in D (Drive). Shift
the transmission to a lower gear if the
transmission shifts too often under
heavy loads and/or hilly conditions.
When towing at higher altitudes,
engine coolant will boil at a lower
temperature than at lower altitudes.
If the engine is turned off immediately
after towing at high altitude on steep
uphill grades, the vehicle could show
signs similar to engine overheating. To
avoid this, let the engine run,
preferably on level ground, with the
transmission in P (Park) for a few
minutes before turning the engine off.
If the overheat warning comes on, see
Engine Overheating0288.
Parking on Hills
{Warning
To prevent serious injury or death,
always park your vehicle and trailer
on a level surface when possible.
When parking your vehicle and your
trailer on a hill: 1. Press the brake pedal, but do not shift into P (Park) yet. Turn the
wheels into the curb if facing
downhill or into traffic if facing
uphill.
2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, release the regular brakes
until the chocks absorb the load.
4. Reapply the brake pedal. Then apply the parking brake and shift
into P (Park).
5. Release the brake pedal.
Leaving After Parking on a Hill
1. Apply and hold the brake pedal. .Start the engine.
. 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 0359. It is
especially important to check the
automatic transmission fluid, 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.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/14/19
DRIVING AND OPERATING 269
Conversions and
Add-Ons
Add-On Electrical
Equipment
{Warning
The Data Link Connector (DLC) is
used for vehicle service and
Emission Inspection/Maintenance
testing. SeeMalfunction Indicator
Lamp (Check Engine Light) 0123.
A device connected to the DLC —
such as an aftermarket fleet or
driver-behavior tracking device —
may interfere with vehicle systems.
This could affect vehicle operation
and cause a crash. Such devices
may also access information stored
in the vehicle’s systems.
Caution
Some electrical equipment can
damage the vehicle or cause
components to not work and would
not be covered by the vehicle
warranty. Always check with your
dealer before adding electrical
equipment.
Add-on equipment can drain the
vehicle's 12-volt battery, even if the
vehicle is not operating.
The vehicle has an airbag system.
Before attempting to add anything
electrical to the vehicle, see Servicing
the Airbag-Equipped Vehicle 075 and
Adding Equipment to the
Airbag-Equipped Vehicle 076.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
270 VEHICLE CARE
Vehicle Care
General Information
General Information . . . . . . . . . . . . . 271
California Proposition65 Warning . . . . . . . . . . . . . . . . . . . . . 271
California Perchlorate Materials Requirements . . . . . . . . . . . . . . . . . . . 272
Accessories and Modifications . . . . . . . . . . . . . . . . . . . 272
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . . . . . . 272
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . . . . . . 274
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . 277
Engine Oil Life System . . . . . . . . . . . 280
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281
Engine Air Filter Life System . . . . 281
Engine Air Cleaner/Filter . . . . . . . . . 282
Cooling System . . . . . . . . . . . . . . . . . . . 284
Engine Overheating . . . . . . . . . . . . . . 288
Washer Fluid . . . . . . . . . . . . . . . . . . . . . 289
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290
Brake Pad Life System . . . . . . . . . . . 291
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . 291 Battery - North America . . . . . . . . . 292
All-Wheel Drive . . . . . . . . . . . . . . . . . . 293
Starter Switch Check . . . . . . . . . . . . . 294
Park Brake and P (Park)
Mechanism Check . . . . . . . . . . . . . . 294
Wiper Blade Replacement . . . . . . . 295
Windshield Replacement . . . . . . . . 295
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . 296
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . 297
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . 297
LED Lighting . . . . . . . . . . . . . . . . . . . . . 297
Electrical System
Electrical System Overload . . . . . . 298
Fuses and Circuit Breakers . . . . . . 298
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299
Instrument Panel Fuse Block . . . . 306
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315
All-Season Tires . . . . . . . . . . . . . . . . . . 316
Winter Tires . . . . . . . . . . . . . . . . . . . . . . 316
Low-Profile Tires . . . . . . . . . . . . . . . . . 317
Summer Tires . . . . . . . . . . . . . . . . . . . . 317
Tire Sidewall Labeling . . . . . . . . . . . 317 Tire Designations . . . . . . . . . . . . . . . . . 319
Tire Terminology and
Definitions . . . . . . . . . . . . . . . . . . . . . . 320
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . 322
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . . . . . . 324
Tire Pressure Monitor System . . . 324
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . . . . . . 325
Tire Inspection . . . . . . . . . . . . . . . . . . . 329
Tire Rotation . . . . . . . . . . . . . . . . . . . . . 329
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
Buying New Tires . . . . . . . . . . . . . . . . 331
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . . . . . 333
Uniform Tire Quality Grading . . . 333
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . . . . . . 334
Wheel Replacement . . . . . . . . . . . . . . 335
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . 335
If a Tire Goes Flat . . . . . . . . . . . . . . . . 336
Tire Changing . . . . . . . . . . . . . . . . . . . . . 337
Compact Spare Tire . . . . . . . . . . . . . . 342Jump Starting
Jump Starting - North America . . . . . . . . . . . . . . . . . . . . . . . . . 343

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
VEHICLE CARE 273
If equipped with remote vehicle start,
open the hood before performing any
service work to prevent remote
starting the vehicle accidentally. See
Remote Vehicle Start017.
Keep a record with all parts receipts
and list the mileage and the date of
any service work performed. See
Maintenance Records 0371.
Caution
Even small amounts of
contamination can cause damage to
vehicle systems. Do not allow
contaminants to contact the fluids,
reservoir caps, or dipsticks.
Hood
{Warning
For vehicles with auto engine stop/
start, turn the vehicle off before
opening the hood. If the vehicle is
on, the engine will start when the
hood is opened. You or others could
be injured.
{Warning
Components under the hood can
get hot from running the engine. To
help avoid the risk of burning
unprotected skin, never touch these
components until they have cooled,
and always use a glove or towel to
avoid direct skin contact.
Clear any snow from the hood before
opening.
To open the hood: 1. Pull the hood release handle with the
isymbol. It is on the
lower left side of the instrument
panel between the door and the
steering wheel. Release the
handle, then pull the handle
again to fully release the hood.
2. After you have partially lifted the hood, the gas strut system will
automatically lift the hood and
hold it in the fully open position. To close the hood:
1. Before closing the hood, be sure all filler caps are on properly,
and all tools are removed.
2. Pull the hood down until the strut system is no longer holding
up the hood.
3. Allow the hood to fall. Check to make sure the hood is latched
completely. Repeat this process
with additional force if necessary.
{Warning
Do not drive the vehicle if the hood
is not latched completely. The hood
could open fully, block your vision,
and cause a crash. You or others
could be injured. Always close the
hood completely before driving.