
Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/6/15
Vehicle Care 273If the system is ever reset
accidentally, the oil must be
changed at 5 000 km (3,000 mi)
since the last oil change.
Remember to reset the oil life
system whenever the oil is changed.
How to Reset the Engine Oil
Life System Reset the system whenever the
engine oil is changed so that the
system can calculate the next
engine oil change. To reset the
system:
1. Using the DIC buttons, display
REMAINING OIL LIFE on the
DIC. See Driver Information
Center (DIC) 0 140 and Engine
Oil Messages 0 149 .
2. Press and hold SEL to clear
the CHANGE ENGINE OIL
SOON message and reset the
oil life at 100%.
Be careful not to reset the oil
life display accidentally at any
time other than after the oil is
changed. It cannot be reset
accurately until the next oil
change. The oil life system can also be reset
as follows:
1. Turn the ignition on with the
engine off.
2. Fully press and release the
accelerator pedal three times
within five seconds.
If the CHANGE ENGINE OIL
SOON message is not on, the
system is reset.
The system is reset when the
CHANGE ENGINE OIL SOON
message is off.
If the CHANGE ENGINE OIL SOON
message comes back on when the
vehicle is started, the engine oil life
system has not been reset. Repeat
the procedure.
Automatic Transmission
Fluid How to Check Automatic
Transmission Fluid
It is not necessary to check the
transmission fluid level.
A transmission fluid leak is the only
reason for fluid loss. If a leak occurs, take the vehicle to your
dealer and have it repaired as soon
as possible.
The vehicle is not equipped with a
transmission fluid level dipstick.
There is a special procedure for
checking and changing the
transmission fluid. Because this
procedure is difficult, this should be
done at the dealer. Contact your
dealer for additional information.
Change the fluid and filter at the
intervals listed in Maintenance
Schedule 0 344 , and be sure to use
the fluid listed in Recommended
Fluids and Lubricants 0 353 .
Engine Air Cleaner/Filter The engine air cleaner/filter is in the
engine compartment. See Engine
Compartment Overview 0 265 .
When to Inspect the Engine Air
Cleaner/Filter
For intervals on changing and
inspecting the engine air cleaner/
filter, see Maintenance
Schedule 0 344 .

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/6/15
Vehicle Care 277
Engine Coolant The cooling system in the vehicle is
filled with DEX-COOL ®
engine
coolant. This coolant needs to be
checked and replaced at
appropriate intervals. See
Maintenance Schedule 0 344 .
The following explains the cooling
system and how to check and add
coolant when it is low. If there is a
problem with engine overheating,
see Engine Overheating 0 280 .
What to Use
{ WarningAdding only plain water or some
other liquid to the cooling system
can be dangerous. Plain water
and other liquids, can boil before
the proper coolant mixture will.
The coolant warning system is set
for the proper coolant mixture.
With plain water or the wrong
mixture, the engine could get too
hot but you would not get the
(Continued) Warning (Continued) overheat warning. The engine
could catch fire and you or others
could be burned. Use a 50/
50 mixture of clean, drinkable
water and DEX-COOL coolant.
Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
coolant. If using this mixture,
nothing else needs to be added.
This mixture:
.
Gives freezing protection down
to − 37 °C ( − 34 °F), outside
temperature.
.
Gives boiling protection up to
129 °C (265 °F), engine
temperature.
.
Protects against rust and
corrosion.
.
Will not damage aluminum parts.
.
Helps keep the proper engine
temperature. CautionIf improper coolant mixture,
inhibitors, or additives are used in
the vehicle cooling system, the
engine could overheat and be
damaged. Too much water in the
mixture can freeze and crack
engine cooling parts. The repairs
would not be covered by the
vehicle warranty. Use only the
proper mixture of engine coolant
for the cooling system. See
Recommended Fluids and
Lubricants 0 353 .
Never dispose of engine coolant by
putting it in the trash, pouring it on
the ground, or into sewers, streams,
or bodies of water. Have the coolant
changed by an authorized service
center, familiar with legal
requirements regarding used
coolant disposal. This will help
protect the environment and your
health.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/6/15
278 Vehicle Care Checking Coolant The vehicle must be on a level
surface when checking the coolant
level.
2.0L L4 and 3.0L V6 Engine
Coolant Surge Tank 3.6L V6 Engine Coolant
Surge Tank
Check to see if coolant is visible in
the coolant surge tank. If the coolant
inside the coolant surge tank is
boiling, do not do anything else until
it cools down. See Engine
Overheating 0 280 .
The coolant surge tank is in the
engine compartment on the
passenger side of the vehicle. See
Engine Compartment
Overview 0 265 . How to Add Coolant to the
Coolant Surge Tank
CautionThis vehicle has a specific
coolant fill procedure. Failure to
follow this procedure could cause
the engine to overheat and be
severely damaged.
If no problem is found, check to see
if coolant is visible in the coolant
surge tank. If coolant is visible but
the coolant level mark is not visible,
add a 50/50 mixture of clean,
drinkable water and DEX-COOL
coolant at the coolant surge tank to
the top rib on the middle of the tank,
but be sure the cooling system,
including the coolant surge tank
pressure cap, is cool before this is
done. See Engine
Overheating 0 280 .

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/6/15
Vehicle Care 279
{ WarningSteam and scalding liquids from a
hot cooling system can blow out
and burn you badly. Never turn
the cap when the cooling system,
including the surge tank pressure
cap, is hot. Wait for the cooling
system and surge tank pressure
cap to cool.
{ WarningAdding only plain water or some
other liquid to the cooling system
can be dangerous. Plain water
and other liquids, can boil before
the proper coolant mixture will.
The coolant warning system is set
for the proper coolant mixture.
With plain water or the wrong
mixture, the engine could get too
hot but you would not get the
overheat warning. The engine
could catch fire and you or others
(Continued) Warning (Continued) could be burned. Use a 50/
50 mixture of clean, drinkable
water and DEX-COOL coolant.
CautionIn cold weather, water can freeze
and crack the engine, radiator,
heater core, and other parts. Use
the recommended coolant and
the proper coolant mixture.
{ Warning
You can be burned if you spill
coolant on hot engine parts.
Coolant contains ethylene glycol
and it will burn if the engine parts
are hot enough. Do not spill
coolant on a hot engine.
1. Remove the coolant surge tank
pressure cap when the cooling
system, including the coolant surge tank pressure cap and
upper radiator hose, is no
longer hot.
Turn the pressure cap slowly
counterclockwise about
one-quarter of a turn. If you
hear a hiss, wait for that to
stop. This will allow any
pressure still left to be vented
out the discharge hose.
2. Keep turning the pressure cap
slowly and remove it.
3. Fill the coolant surge tank with
the proper mixture to the
indicated level mark.
4. With the coolant surge tank
pressure cap off, start the
engine and let it run until you
can feel the upper radiator
hose getting hot. Watch out for
the engine cooling fan.
By this time, the coolant level
inside the coolant surge tank
may be lower. If the level is
lower, add more of the proper
mixture to the coolant surge
tank until the level reaches the
indicated level mark.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/6/15
292 Vehicle Care Number Usage
20 High-beam
headlamp relay
21 A/C clutch
22 –
23 Coolant heater
control module
24 Coolant pump
25 Coolant pump relay
26 HI fuel
27 Steering
column lock
28 Rear heated seats
29 Front heated seats
30 –
31 LED LGT BAT
32 A/C control
module/ –
33 AIR solenoid
34 –
35 Engine control
module Number Usage
36 Engine control
module 2
37 Coolant pump/
Ignition coils – odd
38 Ignition coils – even/
Non walk 2
39 Non walk
40 Instrument cluster
41 –
42 Fuel pump power
module
43 Instrument panel
body/Ignition
44 Aeroshutter
45 Washer
46 Front sensor
47 Left cornering LED
48 AIR solenoid relay
49 Air pump relay
50 Engine control
module relay
51 Wiper speed relay Number Usage
52 Wiper control relay
53 Headlamp control
relay
54 –
55 –
56 Air pump
57 –
58 Instrument panel
electronic center
59 –
60 ABS pump
61 Front wiper
62 Headlamp leveling
63 Electric brake
booster module
64 –
65 –
66 Transfer case
control module
67 Electric brake
booster

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/6/15
344 Service and Maintenance
Cadillac Premium
Care Maintenance Your vehicle comes with the
Cadillac Premium Care
Maintenance. It is a maintenance
program that covers select
maintenance services during the
first 4 years or 80 000 km
(50,000 mi), whichever comes first.
Cadillac Premium Care
Maintenance covers routine
maintenance services, when
scheduled in accordance with the
owner manual, including:
.
Oil changes based on the
vehicle's oil life monitor system.
.
Tire rotation every 12 000 km
(7,500 mi). .
Engine air cleaner filter
replacement.
.
Passenger compartment air filter
replacement.
.
Multi ‐ point vehicle inspection
(MPVI) performed by a qualified
technician.
Cadillac requires that all Cadillac
Premium Care Maintenance
services be performed by a Cadillac
authorized service dealer.
Maintenance
Schedule Owner Checks and Services At Each Fuel Stop
.
Check the engine oil level. See
Engine Oil 0 270 .
Once a Month
.
Check the tire inflation
pressures. See Tire
Pressure 0 306 .
.
Inspect the tires for wear. See
Tire Inspection 0 312 .
.
Check the windshield washer
fluid level. See Washer
Fluid 0 281 .
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

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/6/15
Service and Maintenance 345a 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 0 272 .
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
Rotation 0 313 .
.
Check engine oil level and oil
life percentage. If needed,
change engine oil and filter, and
reset oil life system. See Engine
Oil 0 270 and Engine Oil Life
System 0 272 .
.
Check engine coolant level. See
Engine Coolant 0 277 .
.
Check windshield washer fluid
level. See Washer Fluid 0 281 . .
Visually inspect windshield wiper
blades for wear, cracking,
or contamination. See Exterior
Care 0 333 . Replace worn or
damaged wiper blades. See
Wiper Blade
Replacement 0 286 .
.
Check tire inflation pressures.
See Tire Pressure 0 306 .
.
Inspect tire wear. See Tire
Inspection 0 312 .
.
Visually check for fluid leaks.
.
Inspect engine air cleaner filter.
See Engine Air Cleaner/
Filter 0 273 .
.
Inspect brake system. See
Exterior Care 0 333 .
.
Visually inspect steering,
suspension, and chassis
components for damaged, loose,
or missing parts or signs of
wear. See Exterior Care 0 333 .
.
Check restraint system
components. See Safety System
Check 0 75 .
.
Visually inspect fuel system for
damage or leaks. .
Visually inspect exhaust system
and nearby heat shields for
loose or damaged parts.
.
Lubricate body components. See
Exterior Care 0 333 .
.
Check starter switch. See Starter
Switch Check 0 285 .
.
Check automatic transmission
shift lock control function. See
Automatic Transmission Shift
Lock Control Function
Check 0 285 .
.
Check parking brake and
automatic transmission park
mechanism. See Park Brake and
P (Park) Mechanism
Check 0 286 .
.
Check accelerator pedal for
damage, high effort, or binding.
Replace if needed.
.
Visually inspect gas strut for
signs of wear, cracks, or other
damage. Check the hold open
ability of the strut. See your
dealer if service is required.
.
Inspect sunroof track and seal,
if equipped. See Sunroof 0 55 .

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/6/15
346 Service and Maintenance Maintenance Schedule
Additional Required
Services - Normal
12 000 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 miRotate tires, if recommended for the vehicle, and
perform Required Services. Check engine oil level
and oil life percentage. Change engine oil and
filter, if needed. (1)
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @Replace passenger compartment air filter. (2)
@ @ @ @ @ @Inspect evaporative control system. (3)
@ @ @Replace engine air cleaner filter. (4)
@ @ @Replace spark plugs. Inspect spark plug wires.
(2.0L and 3.0L Twin Turbo Engines)
@ @Replace spark plugs. Inspect spark plug wires.
(3.6L Engine Only)
@Drain and fill engine cooling system. (5)
@Change transfer case fluid, if equipped with
AWD. (6)
@Visually inspect accessory drive belts. (7)
@Replace brake fluid. (8)
Footnotes — Maintenance
Schedule Additional Required
Services - Normal
(1) Vehicles with different size front
and rear tires do not have tire
rotation. See Tire Rotation 0 313 . (2) Or every two years, whichever
comes first. More frequent
passenger compartment air filter
replacement may be needed if
driving in areas with heavy traffic,
poor air quality, high dust levels,
or environmental allergens. Passenger compartment air filter
replacement may also be needed if
there is reduced airflow, window
fogging, or odors. Your GM dealer
can help determine when to replace
the filter.