check engine CADILLAC CT6 2018 1.G Owner's Manual

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
278 DRIVING AND OPERATING
Charging StatusIndicator Sound Action/Reason
Short Flashing Green
(From one to four
flashes depending on
charge level) Two audible beeps Vehicle is charging but will delay at least once
before the charge is complete.
Short Flashing Green
(From one to four
flashes depending on
charge level) or Long
Flashing Green Four audible beeps Insufficient time to fully charge by departure
time due to rate preference.
None (Upon Plug-in) None Charge cord connection should be checked.
None (After Green or
Yellow CSI Indication
Observed) None Charge cord connection should be checked.
If connection is good, this may be due to a
total utility interruption via OnStar and
charging will begin later. The condition may
also occur if the vehicle has detected a fault
with the high voltage charging system.
SeeUtility Interruption of Charging (PLUG-IN
Only) 0284 orMalfunction Indicator Lamp
(Check Engine Light) 0143.

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DRIVING AND OPERATING 287
by the vehicle warranty. If heavy
knocking is heard when using gasoline
rated at 93 octane, the engine needs
service.
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 which 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, and
aniline. These fuels can
corrode metal fuel system
parts or damage plastic and
rubber parts.
. Fuel containing metals such
as methylcyclopentadienyl
manganese tricarbonyl
(Continued)
Caution (Continued)
(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 fuel economy
and performance, and may
decrease the life of the
emissions catalyst.
California Fuel
Requirements
If the vehicle is certified to meet
California Emissions Standards, it is
designed to operate on fuels that meet
California specifications. See the
underhood emission control label.
If this fuel is not available in states
adopting California Emissions
Standards, the vehicle will operate
satisfactorily on fuels meeting federal
specifications, but emission control
system performance may be affected.
The malfunction indicator lamp could
turn on and the vehicle may not pass a smog-check test. See
Malfunction
Indicator Lamp (Check Engine Light)
0 143. If this occurs, return to your
authorized dealer for diagnosis. If it is
determined that the condition is
caused by the type of fuel used,
repairs may not be covered by the
vehicle warranty.
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” inFuel
0 286.
Fuel Additives
To keep fuel systems clean, TOP TIER
detergent gasoline is recommended.
See Fuel 0286.
If TOP TIER detergent gasoline is not
available, one bottle of GM Fuel
System Treatment Cleaner added to
the fuel tank at every engine oil
change, can help. GM Fuel System
Treatment Cleaner is the only gasoline
additive recommended by General
Motors. It is available at your dealer.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
2018 - crc - 2/14/17
DRIVING AND OPERATING 291
.Then during the first 800 km
(500 mi) of trailer towing, do not
drive over 80 km/h (50 mph) and
do not make starts at full throttle.
. 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.
. Do not use Adaptive Cruise
Control when towing.
. The Forward Automatic Braking
system should be set to Off when
towing. See Forward Automatic
Braking (FAB) 0262.
. The Front Pedestrian Braking
system should be set to Alert or
Off when towing. See Front
Pedestrian Braking (FPB) System
0 264.
. Turn off Parking Assist when
towing.{Warning
When towing a trailer, exhaust
gases may collect at the rear of the
vehicle and enter if the liftgate,
trunk/hatch, or rear-most window
is open.
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.
. Also 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
0 230.
Towing a trailer requires a certain
amount of experience. The
combination you are driving is longer
and not as responsive as the vehicle itself. Get acquainted with the
handling and braking of the rig before
setting out for the open road.
Before starting, check all trailer hitch
parts and attachments, safety chains,
electrical connectors, lamps, tires, and
mirrors. If the trailer has electric
brakes, start the combination moving
and then apply the trailer brake
controller by hand to be sure the
brakes work.
During the trip, check occasionally to
be sure that the load is secure and the
lamps and any trailer brakes
still work.
Following Distance
Stay at least twice as far behind the
vehicle ahead as you would when
driving the vehicle 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 will
not accelerate as quickly and is longer
so it is necessary to go much farther
beyond the passed vehicle before
returning to the lane.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
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292 DRIVING AND OPERATING
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
your hand to the right. Always back
up slowly and, if possible, have
someone guide you.
Making TurnsCaution
Making very sharp turns while
trailering could cause the trailer to
come in contact with the vehicle.
The vehicle could be damaged.
Avoid making very sharp turns
while trailering.
When turning with a trailer, make
wider turns than normal. Do this so
the trailer will not strike soft
shoulders, curbs, road signs, trees,
or other objects. Avoid jerky or sudden
maneuvers. Signal well in advance. If the trailer turn signal bulbs burn
out, the arrows on the instrument
cluster will still flash for turns. It is
important to check occasionally to be
sure the trailer bulbs are still working.
Driving on Grades
Reduce speed and shift to a lower gear
before
starting down a long or steep
downgrade. If the transmission is not
shifted down, the brakes might get hot
and no longer work well.
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 high altitude on steep
uphill grades, consider the following:
Engine coolant will boil at a lower
temperature than at normal altitudes.
If the engine is turned off immediately
after towing at high altitude on steep
uphill grades, the vehicle may show
signs similar to engine overheating. To
avoid this, let the engine run while
parked, preferably on level ground,
with the automatic transmission in
P (Park) for a few minutes before turning the engine off. If the overheat
warning comes on, see
Engine
Overheating 0321.
Parking on Hills
{Warning
Parking the vehicle on a hill with
the trailer attached can be
dangerous. If something goes
wrong, the rig could start to move.
People can be injured, and both the
vehicle and the trailer can be
damaged. When possible, always
park the rig on a flat surface.
If parking the rig 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.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
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DRIVING AND OPERATING 293
4. Reapply the brake pedal. Thenapply 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.
2. Start the engine.
3. Shift into a gear.
4. Release the parking brake.
5. Let up on the brake pedal.
6. Drive slowly until the trailer is clear of the chocks.
7. Stop and have someone pick up and store the chocks.
Maintenance when Trailer
Towing
The vehicle needs service more often
when pulling a trailer. . Things that
are especially important in trailer
operation are automatic transmission
fluid, engine oil, axle lubricant, belts,
cooling system, and brake system. It is
a good idea to inspect these before
and during the trip. Check periodically to see that all hitch
nuts and bolts are tight.
Trailer Towing
(PLUG-IN Only)
The vehicle is neither designed nor
intended to tow a trailer.
Trailer Towing
(Gasoline Only)
Before pulling a trailer, three
important considerations have to do
with weight:
.
Weight of the trailer.
. Weight of the trailer tongue.
. Total weight on your vehicle's
tires.
Weight of the Trailer
How heavy can a trailer safely be?
It should never weigh more than
454 kg (1,000 lb). But even that can be
too heavy.
Safe trailering requires monitoring the
weight, speed, altitude, road grades,
outside temperature, the dimensions of the front of the trailer, and how
frequently the vehicle is used to pull a
trailer. Take into consideration any
special equipment on the vehicle, and
the amount of tongue weight the
vehicle can carry. See
“Weight of the
Trailer Tongue ”later in this section
for more information.
Trailer weight rating (TWR) is
calculated assuming the tow vehicle
has the driver, a front seat passenger,
and all required trailering equipment.
Weight of additional optional
equipment, passengers, and cargo in
the tow vehicle must be subtracted
from the trailer weight rating.
Ask your dealer for trailering
information or advice, or write us at
our Customer Assistance Offices. See
Customer Assistance Offices 0410.Weight of the Trailer Tongue
The tongue weight load (1) of any
trailer is very important because it is
also part of the vehicle weight. The
Gross Vehicle Weight (GVW) includes
the curb weight of the vehicle, any
cargo carried in it, and the people who
will be riding in the vehicle, as well as
trailer tongue weight. Vehicle options,

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
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DRIVING AND OPERATING 295
Because the vehicle has antilock
brakes, do not tap into the vehicle's
brake system. If this is done, both
brake systems will not work well or
at all.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) 0143.
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 095 and
Adding Equipment to the
Airbag-Equipped Vehicle 095.

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296 VEHICLE CARE
Vehicle Care
General Information
General Information . . . . . . . . . . . . . 297
California Proposition65 Warning . . . . . . . . . . . . . . . . . . . . . 297
California Perchlorate Materials Requirements . . . . . . . . . . . . . . . . . . . 297
Accessories and Modifications . . . . . . . . . . . . . . . . . . . 298
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . . . . . . 298
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . . . . . . 300
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . 307
Engine Oil Life System . . . . . . . . . . . 309
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310
Engine Air Cleaner/Filter . . . . . . . . . 311
Cooling System (Gasoline Only) . . . . . . . . . . . . . . . . . 312
Cooling System (PLUG-IN Only) . . . . . . . . . . . . . . . . . 316
Engine Overheating . . . . . . . . . . . . . . 321
Washer Fluid . . . . . . . . . . . . . . . . . . . . . 322
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . 323 Battery - North America . . . . . . . . . 324
All-Wheel Drive . . . . . . . . . . . . . . . . . . 326
Starter Switch Check . . . . . . . . . . . . . 326
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327
Park Brake and P (Park) Mechanism Check . . . . . . . . . . . . . . 327
Wiper Blade Replacement . . . . . . . 327
Windshield Replacement . . . . . . . . 328
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . 328
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . . . . . 329
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . 330
LED Lighting . . . . . . . . . . . . . . . . . . . . . 330
License Plate Lamp . . . . . . . . . . . . . . 330
Replacement Bulbs . . . . . . . . . . . . . . . 330
Electrical System
Electrical System Overload . . . . . . 331
Fuses and Circuit Breakers . . . . . . 331
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
Instrument Panel Fuse Block . . . . 335
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340 All-Season Tires . . . . . . . . . . . . . . . . . . 341
Winter Tires . . . . . . . . . . . . . . . . . . . . . . 341
Low-Profile Tires . . . . . . . . . . . . . . . . . 342
Summer Tires . . . . . . . . . . . . . . . . . . . . 342
Tire Sidewall Labeling . . . . . . . . . . . 342
Tire Designations . . . . . . . . . . . . . . . . . 344
Tire Terminology and
Definitions . . . . . . . . . . . . . . . . . . . . . . 345
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . 347
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . . . . . . 349
Tire Pressure Monitor System . . . 349
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . . . . . . 350
Tire Inspection . . . . . . . . . . . . . . . . . . . 353
Tire Rotation . . . . . . . . . . . . . . . . . . . . . 353
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355
Buying New Tires . . . . . . . . . . . . . . . . 355
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . . . . . 357
Uniform Tire Quality Grading . . . 357
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . . . . . . 359
Wheel Replacement . . . . . . . . . . . . . . 359
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . 360
If a Tire Goes Flat . . . . . . . . . . . . . . . . 360
Tire Sealant and Compressor Kit . . . . . . . . . . . . . . . . . 362
Storing the Tire Sealant and Compressor Kit . . . . . . . . . . . . . . . . . 368

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
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VEHICLE CARE 299
Keep a record with all parts receipts
and list the mileage and the date of
any service work performed. See
Maintenance Records0402.
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
Gas struts and other metal
components under the hood can get
hot after running the engine. Do
not touch these components as
they can burn unprotected skin and
could cause serious injury.
Clear any snow from the hood before
opening. To open the hood:
1. Pull the hood release handle. It is
on the lower left side of the
instrument panel between the
door and the steering wheel.
2. Release the handle, then pull the handle again to fully open
the hood.
3. Go to the front of the vehicle and lift the hood open.
Caution
Be sure the hood is completely
closed before driving. Damage may
occur if it is not. To close the hood:
1. Before closing the hood, be sure all filler caps are properly
installed.
2. Lower the hood approximately 46 cm (18 in) from the closed
position.
3. Then push the front center of the hood with a swift, firm motion.
4. Check to make sure the hood is closed. If not, release the hood
from inside and repeat Steps 1–3.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
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VEHICLE CARE 307
1. Engine Coolant Surge Tank andPressure Cap.
See Cooling System (Gasoline
Only) 0312 orCooling System
(PLUG-IN Only) 0316.
2. Engine Air Cleaner/Filter 0311.
3. Engine Cooling Fan (Out of View).
See Cooling System (Gasoline
Only) 0312 orCooling System
(PLUG-IN Only) 0316.
4. Engine Oil Fill Cap. See Engine Oil
0 307.
5. Engine Oil Dipstick. See Engine
Oil 0307.
6. Remote Positive (+) Battery Terminal. See Jump Starting -
North America 0374.
7. Engine Compartment Fuse Block
0332.
8. Brake Fluid Reservoir. See Brake
Fluid 0323.
9. Windshield Washer Fluid Reservoir. See Washer Fluid
0 322. 10. Remote Negative (-) Battery
Terminal. See Jump Starting -
North America 0374.
Engine Oil
To ensure proper engine performance
and long life, careful attention must
be paid to engine oil. Following these
simple, but important steps will help
protect your investment:
.
Use engine oil approved to the
proper specification and of the
proper viscosity grade. See
“Selecting the Right Engine Oil” in
this section.
. Check the engine oil level regularly
and maintain the proper oil level.
See “Checking Engine Oil” and
“When to Add Engine Oil” later in
this section.
. Change the engine oil at the
appropriate time. See Engine Oil
Life System 0309.
. Always dispose of engine oil
properly. See “What to Do with
Used Oil” in this section.
Checking Engine Oil
Check the engine oil level regularly,
every 650 km (400 mi), especially prior
to a long trip. The engine oil dipstick
handle is a loop. See Engine
Compartment Overview 0300 for the
location.
{Warning
The engine oil dipstick handle may
be hot; it could burn you. Use a
towel or glove to touch the dipstick
handle.
If a low oil Driver Information Center
(DIC) message displays, check the oil
level.
Follow these guidelines:
. To get an accurate reading, park
the vehicle on level ground. Check
the engine oil level after the
engine has been off for at least
two hours. Checking the engine oil
level on steep grades or too soon
after engine shutoff can result in
incorrect readings. Accuracy

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-11292458) -
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308 VEHICLE CARE
improves when checking a cold
engine prior to starting. Remove
the dipstick and check the level.
. If unable to wait two hours, the
engine must be off for at least
15 minutes if the engine is warm,
or at least 30 minutes if the
engine is not warm. Pull out the
dipstick, wipe it with a clean paper
towel or cloth, then push it back
in all the way. Remove it again,
keeping the tip down, and check
the level.
When to Add Engine Oil
2.0L L4 Engine
3.0L and 3.6L V6 Engines
If the oil is below the cross-hatched
area at the tip of the dipstick and the
engine has been off for at least
15 minutes, add 1 L (1 qt) of the
recommended oil and then recheck
the level. See “Selecting the Right
Engine Oil” later in this section for an
explanation of what kind of oil to use.
For engine oil crankcase capacity, see
Capacities and Specifications 0404.
Caution
Do not add too much oil. Oil levels
above or below the acceptable
operating range shown on the
dipstick are harmful to the engine.
If you find that you have an oil
level above the operating range, i.e.,
the engine has so much oil that the
oil level gets above the
(Continued)
Caution (Continued)
cross-hatched area that shows the
proper operating range, the engine
could be damaged. You should
drain out the excess oil or limit
driving of the vehicle and seek a
service professional to remove the
excess amount of oil.
See Engine Compartment Overview
0 300 for the location of the engine oil
fill cap.
Add enough oil to put the level
somewhere in the proper operating
range. Push the dipstick all the way
back in when through.
Selecting the Right Engine Oil
Selecting the right engine oil depends
on both the proper oil specification
and viscosity grade. See Recommended
Fluids and Lubricants 0399.
Specification
Ask for and use engine oils that meet
the dexos1™ specification. Engine oils
that have been approved by GM as