2020 CADILLAC CT6 check engine

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
SERVICE AND MAINTENANCE 359
Maintenance Schedule
Owner Checks and Services
Check the engine oil level. SeeEngine
Oil 0277.
Once a Month
. Check the tire inflation pressures.
See Tire Pressure 0322.
. Inspect the tires for wear. See Tire
Inspection 0329.
. Check the windshield washer fluid
level. See Washer Fluid 0289.
Engine Oil Change
When the CHANGE ENGINE OIL
SOON message displays, have the
engine oil and filter changed within
the next 1 000 km (600 mi). If driven
under the best conditions, the engine
oil life system may not indicate the
need for vehicle service for up to a
year. The engine oil and filter must be
changed at least once a year and the
oil life system must be reset. Your
trained dealer technician can perform
this work. If the engine oil life system
is reset accidentally, service the vehicle within 5 000 km (3,000 mi)
since the last service. Reset the oil life
system when the oil is changed. See
Engine Oil Life System
0280.
Engine Air Filter Change
When the REPLACE AT NEXT OIL
CHANGE message displays, the engine
air filter should be replaced at the
next engine oil change. When the
REPLACE ENGINE AIR FILTER SOON
message displays, the engine air filter
should be replaced at the earliest
convenience. Reset the engine air
filter life system after the engine air
filter is replaced. See Engine Air Filter
Life System 0281.
Air Conditioning Desiccant
(Replace Every Seven Years)
The air conditioning system requires
maintenance every seven years. This
service requires replacement of the
desiccant to help the longevity and
efficient operation of the air
conditioning system. This service can
be complex. See your dealer.
Tire Rotation and Required
Services Every 12 000 km
(7,500 mi)
Rotate the tires, if recommended for
the vehicle, and perform the following
services. See Tire Rotation0329.
. Check engine oil level and oil
life percentage. If needed,
change engine oil and filter,
and reset oil life system. See
Engine Oil 0277 and
Engine Oil Life System 0280.
. If equipped with the engine air
filter life system, check the air
filter life percentage. If necessary,
replace the engine air filter and
reset the engine air filter life
system. See Engine Air Filter Life
System 0281. If the vehicle is not
equipped with the engine air filter
life system, inspect the engine air
cleaner filter. See Engine Air
Cleaner/Filter 0282.
. Check engine coolant level. See
Cooling System 0284.
. Check windshield washer fluid
level. See Washer Fluid 0289.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
SERVICE AND MAINTENANCE 361
Maintenance Schedule
Additional Required Services -
Normal12 000 km/7,500 mi
24 000 km/15,000 mi
36 000 km/22,500 mi
48 000 km/30,000 mi
60 000 km/37,500 mi
72 000 km/45,000 mi
84 000 km/52,500 mi
96 000 km/60,000 mi
108 000 km/67,500 mi
120 000 km/75,000 mi
132 000 km/82,500 mi
144 000 km/90,000 mi
156 000 km/97,500 mi
168 000 km/105,000 mi
180 000 km/112,500 mi
192 000 km/120,000 mi
204 000 km/127,500 mi
216 000 km/135,000 mi
228 000 km/142,500 mi
240 000 km/150,000 mi
Rotate tires, if recommended for the vehicle, and
perform Required Services. (1) Check engine oil level
and oil life percentage. Change engine oil and filter,
if needed. Check engine air filter life percentage and
status. Change engine air filter, if needed.
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
Replace passenger compartment air filter. (2)@ @@@@@
Inspect evaporative control system. (3)@ @@
Replace spark plugs. Inspect spark plug wires and/or
boots. (4.2L Engine)@ @
Replace spark plugs. Inspect spark plug wires and/or
boots. (3.6L Engine)@
Change transfer case fluid. (4)@
Change rear axle fluid. (Except V-Series) (4)@
Change rear axle fluid. (V-Series Only) (4)@@@
Change front axle fluid 4WD. (4)@
Drain and fill engine cooling system. (5)@
Visually inspect accessory drive belts. (6)@
Replace brake fluid. (7)
Replace windshield wiper blades. (8)
@ @ @ @ @ @ @ @ @ @
Replace hood and/or body lift support gas struts. (9)@ @
Replace air conditioning desiccant. (10)

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
SERVICE AND MAINTENANCE 363
Maintenance Schedule
Additional Required Services -
Severe12 000 km/7,500 mi
24 000 km/15,000 mi
36 000 km/22,500 mi
48 000 km/30,000 mi
60 000 km/37,500 mi
72 000 km/45,000 mi
84 000 km/52,500 mi
96 000 km/60,000 mi
108 000 km/67,500 mi
120 000 km/75,000 mi
132 000 km/82,500 mi
144 000 km/90,000 mi
156 000 km/97,500 mi
168 000 km/105,000 mi
180 000 km/112,500 mi
192 000 km/120,000 mi
204 000 km/127,500 mi
216 000 km/135,000 mi
228 000 km/142,500 mi
240 000 km/150,000 mi
Rotate tires, if recommended for the vehicle, and
perform Required Services. (1) Check engine oil level
and oil life percentage. Change engine oil and filter,
if needed. Check engine air filter life percentage and
status. Change engine air filter, if needed.
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
Replace passenger compartment air filter. (2)@ @@@@@
Inspect evaporative control system. (3)@ @@
Replace spark plugs. Inspect spark plug wires and/or
boots. (4.2L Engine)@ @
Replace spark plugs. Inspect spark plug wires and/or
boots. (3.6L Engine)@
Change automatic transmission fluid and filter.@@@
Change transfer case fluid. (4)@@@
Change rear axle fluid. (4)@@@
Change front axle fluid 4WD. (4)@@@
Drain and fill engine cooling system. (5)@
Visually inspect accessory drive belts. (6)@
Replace brake fluid. (7)
Replace windshield wiper blades. (8)
@ @ @ @ @ @ @ @ @ @
Replace hood and/or body lift support gas struts. (9)@ @
Replace air conditioning desiccant. (10)

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
SERVICE AND MAINTENANCE 365
Additional Maintenance
and Care
Your vehicle is an important
investment and caring for it properly
may help to avoid future costly
repairs. To maintain vehicle
performance, additional maintenance
services may be required.
It is recommended that your dealer
perform these services—their trained
dealer technicians know your vehicle
best. Your dealer can also perform a
thorough assessment with a
multi-point inspection to recommend
when your vehicle may need
attention.
The following list is intended to
explain the services and conditions to
look for that may indicate services are
required. Battery
The 12-volt battery supplies power to
start the engine and operate any
additional electrical accessories.
.
To avoid break-down or failure to
start the vehicle, maintain a
battery with full cranking power.
. Trained dealer technicians have
the diagnostic equipment to test
the battery and ensure that the
connections and cables are
corrosion-free.
Belts
. Belts may need replacing if they
squeak or show signs of cracking
or splitting.
. Trained dealer technicians have
access to tools and equipment to
inspect the belts and recommend
adjustment or replacement when
necessary. Brakes
Brakes stop the vehicle and are crucial
to safe driving.
.
Signs of brake wear may include
chirping, grinding, or squealing
noises, or difficulty stopping.
. Trained dealer technicians have
access to tools and equipment to
inspect the brakes and recommend
quality parts engineered for the
vehicle.
Fluids
Proper fluid levels and approved fluids
protect the vehicle’s systems and
components. See Recommended Fluids
and Lubricants 0368 for GM approved
fluids.
. Engine oil and windshield washer
fluid levels should be checked at
every fuel fill.
. Instrument cluster lights may
come on to indicate that fluids
may be low and need to be filled.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
374 TECHNICAL DATA
ApplicationCapacities
Metric English
Front Axle 0.4 L 0.42 qt
Rear Axle 0.5 L 0.53 qt
Rear Axle 4.2L V8 Twin Turbo (LTA) Engine or V-Series 1.1 L 1.16 qt
Fuel Tank 72.7 L 19.2 gal
Transfer Case –AWD 0.8 L 0.85 qt
Wheel Nut Torque 150 Y110 lb ft
All capacities are approximate. When adding, be sure to fill to the approximate level, as recommended in this manual.
Recheck fluid level after filling.
*Engine cooling system capacity values are based on the entire cooling system and its components.
Engine Specifications
Engine VIN CodeTransmission Spark Plug Gap
3.6L V6 Engine (LGX) SAutomatic0.80–0.90 mm (0.031–0.035 in)
4.2L V8 Engine (LTA) JAutomatic 0.74–0.75 mm (0.029–0.030 in)
Spark plug gaps are preset by the manufacturer. Re-gapping the spark plug is not recommended and can damage the
spark plug.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
CUSTOMER INFORMATION 385
Managing the Vehicle Damage
Repair Process
In the event that the vehicle requires
damage repairs, GM recommends that
you take an active role in its repair.
If you have a pre-determined repair
facility of choice, take the vehicle
there, or have it towed there. Specify
to the facility that any required
replacement collision parts be original
equipment parts, either new Genuine
GM parts or recycled original GM
parts. Remember, recycled parts will
not be covered by the GM vehicle
warranty.
Insurance pays the bill for the repair,
but you must live with the repair.
Depending on your policy limits, your
insurance company may initially value
the repair using aftermarket parts.
Discuss this with the repair
professional, and insist on Genuine
GM parts. Remember, if the vehicle is
leased, you may be obligated to have
the vehicle repaired with Genuine GM
parts, even if your insurance coverage
does not pay the full cost.If another party's insurance company
is paying for the repairs, you are not
obligated to accept a repair valuation
based on that insurance company's
collision policy repair limits, as you
have no contractual limits with that
company. In such cases, you can have
control of the repair and parts choices
as long as the cost stays within
reasonable limits.
Publication Ordering
Information
Service Manuals
Service manuals have the diagnosis
and repair information on the engine,
transmission, axle, suspension, brakes,
electrical system, steering system,
body, etc.
Customer Literature
Owner’s manuals are written
specifically for owners and are
intended to provide basic operational
information about the vehicle. The
owner’s manual includes the
Maintenance Schedule for all models.Customer literature publications
available for purchase include owner’s
manuals, warranty manuals,
infotainment manuals, and portfolios.
Portfolios include an owner’s manual,
warranty manual, infotainment
manual, if applicable, and zip lock bag
or pouch.
Current and Past Models
Service manuals and customer
literature are available for many
current and past model year GM
vehicles.
To order, call 1-800-551-4123
Monday–Friday, 8:00 a.m.–6:00 p.m.
eastern time
For credit card orders only (VISA,
MasterCard, or Discover), see Helm,
Inc. at: www.helminc.com.
To order by mail, write to:
Helm, Incorporated
Attention: Customer Service
47911 Halyard Drive
Plymouth, MI 48170
Make checks payable in U.S. funds.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
ONSTAR 391
Or
.Give OnStar Turn-by-Turn
Navigation voice commands.
. Obtain and customize the Wi-Fi
hotspot name or SSID and
password, if equipped.
Press
Qto connect to an Advisor to:
. Verify account information or
update contact information.
. Get driving directions.
. Receive a Diagnostic check of the
vehicle's key operating systems.
. Receive Roadside Service.
. Manage Wi-Fi Settings,
if equipped.
Press
>to get a priority connection
to an OnStar Advisor available 24/7 to:
. Get help for an emergency.
. Be a Good Samaritan or respond
to an AMBER Alert.
. Get assistance in severe weather
or other crisis situations and find
evacuation routes.
OnStar Services
Emergency
Emergency Services require an active
safety and security plan. With
Automatic Crash Response, built-in
sensors can automatically alert a
specially trained OnStar Advisor who
is immediately connected in to the
vehicle to help.
Press
>for a priority connection to
an OnStar Advisor who can contact
emergency service providers, direct
them to your exact location, and relay
important information.
With OnStar Crisis Assist, specially
trained Advisors are available
24 hours a day, 7 days a week, to
provide a central point of contact,
assistance, and information during a
crisis.
With Roadside Service, Advisors can
locate a nearby service provider to
help with a flat tire, a battery jump,
or an empty gas tank.
Security
If equipped, OnStar provides these
services:
. With Stolen Vehicle Assistance,
OnStar Advisors can use GPS to
pinpoint the vehicle and help
authorities quickly recover it.
. With Remote Ignition Block,
if equipped, OnStar can block the
engine from being restarted.
. With Stolen Vehicle Slowdown,
if equipped, OnStar can work with
law enforcement to gradually slow
the vehicle down.
Theft Alarm Notification
If equipped, if the doors are locked
and the vehicle alarm sounds, a
notification by text, e-mail, or phone
call will be sent. If the vehicle is
stolen, an OnStar Advisor can work
with authorities to recover the vehicle.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
400 INDEX
IndexA
Accessories and Modifications . . . . . 272
Accessory Power . . . . . . . . . . . . . . . . . . . . 188
Active Fuel Management . . . . . . . . . . . 191
Adaptive Cruise Control . . . . . . . . . . . . 211
Add-On Electrical Equipment . . . . . . 269
Additional InformationOnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 392
Additional Maintenance and Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 365
Adjustments Lumbar, Front Seats . . . . . . . . . . . . . . . . 46
Lumbar, Rear Seats . . . . . . . . . . . . . . . . . 55
Thigh Support . . . . . . . . . . . . . . . . . . . . . . 47
Air Cleaner/Filter, Engine . . . . . . . . . . 282
Air Conditioning . . . . . . . . . . . . . . .158, 163
Air Filter Life System . . . . . . . . . . . . . . . . . . . . . . . . 281
Air Filter, Passenger
Compartment . . . . . . . . . . . . . . . . . . . . . 170
Air Vents . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
Airbag System Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
How Does an Airbag Restrain? . . . . . 70
Passenger Sensing System . . . . . . . . . 71
What Makes an Airbag Inflate? . . . . 69
What Will You See after anAirbag Inflates? . . . . . . . . . . . . . . . . . . . 70 Airbag System (cont'd)
When Should an Airbag
Inflate? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Where Are the Airbags? . . . . . . . . . . . . 67
Airbags Adding Equipment to theVehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Passenger Status Indicator . . . . . . . 121
Readiness Light . . . . . . . . . . . . . . . . . . . 121
Servicing Airbag-Equipped Vehicles . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
System Check . . . . . . . . . . . . . . . . . . . . . . . 65
Alarm Vehicle Security . . . . . . . . . . . . . . . . . . . . . 30
Alert Lane Change . . . . . . . . . . . . . . . . . . . . . . 252
Rear Pedestrian . . . . . . . . . . . . . . . . . . . 242
Side Blind Zone (SBZA) . . . . . . . . . . 252
All-Season Tires . . . . . . . . . . . . . . . . . . . . . 316
All-Wheel Drive . . . . . . . . . . . . . . . .199, 293
Antilock Brake System (ABS) . . . . . . 199 Warning Light . . . . . . . . . . . . . . . . . . . . 126
Appearance Care
Exterior . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349
Interior . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353
Armrest Storage . . . . . . . . . . . . . . . . . . . . . . 99
Assistance Systems for Driving . . . . 243