2016 CADILLAC CT6 engine coolant

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
280 Vehicle Care 5. Replace the pressure cap
tightly.
6. Verify coolant level after the
engine is shut off and the
coolant is cold. If necessary,
repeat coolant fill procedure
Steps 1 – 6.
If the coolant still is not at the
proper level when the system
cools down again, see your
dealer.
CautionIf the pressure cap is not tightly
installed, coolant loss and
possible engine damage may
occur. Be sure the cap is properly
and tightly secured.
Engine Overheating The vehicle has several indicators
to warn of the engine overheating.
There is an engine coolant
temperature gauge and an engine
coolant temperature warning light on the instrument cluster. See Engine
Coolant Temperature Gauge 0 128
and Engine Coolant Temperature
Warning Light 0 137 . The vehicle
may also display a message on the
Driver Information Center (DIC).
See Engine Cooling System
Messages 0 149 .
If the decision is made not to lift the
hood when this warning appears,
get service help right away. See
Roadside Service 0 364 .
If the decision is made to lift the
hood, make sure the vehicle is
parked on a level surface. Then
check to see if the engine cooling
fan is running. If the engine is
overheating, the fan should be
running. If it is not, do not continue
to run the engine. Have the vehicle
serviced.
Caution
Running the engine without
coolant may cause damage or a
fire. Vehicle damage would not be
covered by the vehicle warranty. If Steam Is Coming from the
Engine Compartment
{ WarningSteam from an overheated engine
can burn you badly, even if you
just open the hood. Stay away
from the engine if you see or hear
steam coming from it. Just turn it
off and get everyone away from
the vehicle until it cools down.
Wait until there is no sign of
steam or coolant before you open
the hood.
If you keep driving when the
engine is overheated, the liquids
in it can catch fire. You or others
could be badly burned. Stop the
engine if it overheats, and get out
of the vehicle until the engine
is cool.
If No Steam Is Coming from
the Engine Compartment
If an engine overheat warning is
displayed but no steam can be seen
or heard, the problem may not be

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/6/15
Vehicle Care 281too serious. Sometimes the engine
can get a little too hot when the
vehicle:
.
Climbs a long hill on a hot day.
.
Stops after high-speed driving.
.
Idles for long periods in traffic.
If the overheat warning is displayed
with no sign of steam:
1. Turn the air conditioning off.
2. Turn the heater on to the
highest temperature and to the
highest fan speed. Open the
windows as necessary.
3. When it is safe to do so, pull off
the road, shift to P (Park) or
N (Neutral), and let the
engine idle.
If the engine coolant temperature
gauge is no longer in the
overheated area or the engine
coolant temperature warning light no
longer displays, the vehicle can be
driven. Continue to drive the vehicle
slowly for about 10 minutes. Keep a
safe distance from the vehicle in
front. If the warning does not come back on, continue to drive normally
and have the cooling system
checked for proper fill and function.
If the warning continues, pull over,
stop, and park the vehicle
right away.
If there is no sign of steam, idle the
engine for three minutes while
parked. If the warning is still
displayed, turn off the engine until it
cools down.
Washer Fluid What to Use When windshield washer fluid is
needed, be sure to read the
manufacturer's instructions before
use. If operating the vehicle in an
area where the temperature may fall
below freezing, use a fluid that has
sufficient protection against
freezing. Adding Washer Fluid
Open the cap with the washer
symbol on it. Add washer fluid until
the tank is full. See Engine
Compartment Overview 0 265 for
reservoir location.
Caution .
Do not use washer fluid that
contains any type of water
repellent coating. This can
cause the wiper blades to
chatter or skip.
.
Do not use engine coolant
(antifreeze) in the
windshield washer. It can
damage the windshield
washer system and paint.
(Continued)

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
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
Service and Maintenance 353
Recommended Fluids, Lubricants, and Parts Recommended Fluids and Lubricants Usage Fluid/Lubricant
Engine Oil Engine oil meeting the dexos1 ™ specification of the proper SAE viscosity
grade. AC Delco dexos1 Synthetic Blend is recommended. See Engine
Oil 0 270 .
Engine Coolant 50/50 mixture of clean, drinkable water and use only DEX-COOL ®
Coolant.
See Engine Coolant 0 277 .
Hydraulic Brake System DOT 3 Hydraulic Brake Fluid (GM Part No. 19299818, in
Canada 19299819).
Windshield Washer Automotive windshield washer fluid that meets regional freeze protection
requirements.
Automatic Transmission DEXRON ®
-HP Automatic Transmission Fluid (GM Part No. 19300536, in
Canada 19300537).
Transfer Case (All-Wheel Drive) Transfer Case Fluid (GM Part No. 19331044, in Canada 19331045).
Rear Axle SAE 75W-90 Synthetic Axle Lubricant (GM Part No. 88863089, in
Canada 88863090) meeting GM Specification 9986285.
Rear Axle/Front Axle (All-Wheel
Drive) SAE 75W-90 Synthetic Axle Lubricant (GM Part No. 88863089, in
Canada 88863090).
Hood Latch Assembly, Pivots, Spring
Anchor, and Release Pawl Lubriplate Lubricant Aerosol (GM Part No. 89021668, in
Canada 89021674) or lubricant meeting requirements of NLGI #2,
Category LB or GC-LB.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-9235592) -
2016 - crc - 11/6/15
Index 387Cleaning (cont'd)
Interior Care . . . . . . . . . . . . . . . . . . 338
Climate Control Systems
Automatic . . . . . . . . . . . . . . . . 178, 185
Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
Cluster, Instrument . . . . . . . . 118, 121
Collision Damage Repair . . . . . . . 368
Compact Spare Tire . . . . . . . . . . . . 326
Compartments
Storage . . . . . . . . . . . . . . . . . . . . . . . 106
Compass . . . . . . . . . . . . . . . . . . . . . . . 113
Messages . . . . . . . . . . . . . . . . . . . . 148
Connections
OnStar ®
. . . . . . . . . . . . . . . . . . . . . . 377
Control
Traction and Electronic
Stability . . . . . . . . . . . . . . . . . . . . . 217
Control of a Vehicle . . . . . . . . . . . . . 193
Convenience Net . . . . . . . . . . . . . . . 108
Convex Mirrors . . . . . . . . . . . . . . . . . . 48
Coolant
Engine . . . . . . . . . . . . . . . . . . . . . . . . 277
Engine Temperature Gauge . . 128
Engine Temperature
Warning Light . . . . . . . . . . . . . . . 137
Cooling System . . . . . . . . . . . . . . . . . 275
Engine Messages . . . . . . . . . . . . 149
Courtesy Lamps . . . . . . . . . . . . . . . . 174 Courtesy Transportation
Program . . . . . . . . . . . . . . . . . . . . . . . 367
Cruise Control . . . . . . . . . . . . . . . . . . 220
Light . . . . . . . . . . . . . . . . . . . . . . . . . . 140
Messages . . . . . . . . . . . . . . . . . . . . 148
Cruise Control, Adaptive . . . . . . . . 223
Customer Assistance . . . . . . . . . . . 364
Offices . . . . . . . . . . . . . . . . . . . . . . . . 363
Text Telephone (TTY)
Users . . . . . . . . . . . . . . . . . . . . . . . 364
Customer Information
Service Publications
Ordering Information . . . . . . . . 370
Customer Satisfaction
Procedure . . . . . . . . . . . . . . . . . . . . . 361
D Damage Repair, Collision . . . . . . . 368
Danger, Warning, and Caution . . . . 2
Data Recorders, Event . . . . . . . . . 373
Daytime Running
Lamps (DRL) . . . . . . . . . . . . . . . . . . 172
Defensive Driving . . . . . . . . . . . . . . . 193
Delayed Locking . . . . . . . . . . . . . . . . . 39
Diagnostics
OnStar ®
. . . . . . . . . . . . . . . . . . . . . . 379
Distracted Driving . . . . . . . . . . . . . . . 192
Dome Lamps . . . . . . . . . . . . . . . . . . . 174 Door
Ajar Light . . . . . . . . . . . . . . . . . . . . . 140
Ajar Messages . . . . . . . . . . . . . . . 148
Delayed Locking . . . . . . . . . . . . . . . . 39
Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Power Locks . . . . . . . . . . . . . . . . . . . . 39
Rear Seat Pass-Through . . . . . . . 69
Drive Belt Routing, Engine . . . . . . 360
Drive Systems
All-Wheel Drive . . . . . . . . . . 213, 284
Driver Assistance Systems . . . . . 230
Driver Information
Center (DIC) . . . . . . . . . . . . . . . . . . 140
Driver Mode Control . . . . . . . . . . . . 219
Driving
Assistance Systems . . . . . . . . . . 237
Characteristics and
Towing Tips . . . . . . . . . . . . . . . . . 255
Defensive . . . . . . . . . . . . . . . . . . . . . 193
Drunk . . . . . . . . . . . . . . . . . . . . . . . . . 193
For Better Fuel Economy . . . . . . . 27
Hill and Mountain Roads . . . . . . 196
If the Vehicle is Stuck . . . . . . . . . 198
Loss of Control . . . . . . . . . . . . . . . 195
Off-Road Recovery . . . . . . . . . . . 194
Vehicle Load Limits . . . . . . . . . . . 198
Wet Roads . . . . . . . . . . . . . . . . . . . 195
Winter . . . . . . . . . . . . . . . . . . . . . . . . 197