2019 CADILLAC CT6 cooling

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
312 VEHICLE CARE
At the end of the cycle, check the
coolant level in the surge tank and
add coolant if it is low. Turn off the
vehicle, allow the Electronic Control
Module (ECM) to go to sleep, about
2 minutes, and repeat Steps 4-7.
Listen for pump activation and
movement of the control valves while
watching the level of the coolant in
the surge tank. If the tank empties,
turn the ignition off, carefully remove
the surge tank cap, refill to the COLD
FILL mark, and repeat Steps 4-7. The
fill and air removal process will run
for approximately 10 minutes.
4.2L V8 Engine OnlyCaution
This vehicle has a specific coolant
fill procedure. Failure to follow this
procedure could cause the engine to
overheat and be severely damaged.
See your dealer for assistance.
Because of possible engine failure or
damage if performed without the
proper tools and information, engine coolant should only be added
by a qualified technician. See your
dealer.
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 0135 and
Engine Coolant Temperature Warning
Light 0146. The vehicle may also
display a message on the Driver
Information Center (DIC).
If the decision is made not to lift the
hood when this warning appears, get
service help right away. See Roadside
Service 0405.
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
Do not run the engine if there is a
leak in the engine cooling system.
This can cause a loss of all coolant
and can damage the system and
vehicle. Have any leaks fixed
right away.
If Steam Is Coming from the
Engine Compartment
{Warning
Steam and scalding liquids from a
hot cooling system are under
pressure. Turning the pressure cap,
even a little, can cause them to
come out at high speed and you
could be burned. Never turn the cap
when the cooling system, including
the pressure cap, is hot. Wait for
the cooling system and pressure
cap to cool.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
VEHICLE CARE 313
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 too
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 0292 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-12533370) -
2019 - crc - 1/23/19
VEHICLE CARE 325
FusesUsage
22 Transmission auxiliary oil pump
cooling
23 –
24 Cabin heater pump
26 Engine control module ignition
27 Steering column lock ignition
28 Rear heated seats ignition
29 Front heated seats ignition
30 –
31 Headlamp/Daytime running lamps/Right
headlamp
32 –
33 –
34 –
35 Engine control module ignition –2 Fuses
Usage
36 Engine control module ignition –1
37 Coolant pump/ Ignition coils –odd
38 Ignition coils –even/
Non walk 2
39 Non walk
40 Electric brake control module1/Instrument
cluster/central
gateway module
ignition
41 –
42 Fuel tank zone module/Ignition
43 Heated steering wheel module/
Reflective light aux
display/HVAC IGN/
Automatic occupant
sensing display
44 Aeroshutter
45 Washer Fuses
Usage
46 Front short range radar sensors
47 Left cornering LED
54 –
55 –
56 –
57 –
58 –
59 –
60 Antilock brake system pump/Electric
brake control
module–1
61 Front wiper
62 Headlamp leveling
63 –
64 –
66 Transfer case control module
67 –
68 –

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
VEHICLE CARE 329
FusesUsage
F1 Electric brake control module–2
F2 –
F3 Headlamp/Daytime running lamps
F4 Right cornering LED
F5 – Fuses
Usage
F6 Front short range radar sensors
F7 Horn
F8 Air conditioning clutch
F9 –
F10 – Fuses
Usage
F11 Automatic headlamp leveling
F12 Starter motor
F13 Starter pinion
F14 –
F15 –
F16 –
F17 Cabin heater pump
F18 Transmission auxiliary oil pump
cooling
F19 Engine control module ignition
F20 Non walk
F21 Ignition coils –even/
Non walk –2
F22 Engine control module ignition –1
F23 Transfer case control module
F24 –
F25 Ignition coils –odd

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
VEHICLE CARE 359
Warning (Continued)
vehicle. Tires can lose air, and
cause loss of control, causing a
crash. Always use the correct wheel,
wheel bolts, and wheel nuts for
replacement.
Caution
The wrong wheel can also cause
problems with bearing life, brake
cooling, speedometer or odometer
calibration, headlamp aim, bumper
height, vehicle ground clearance,
and tire or tire chain clearance to
the body and chassis.
Used Replacement Wheels
{Warning
Replacing a wheel with a used one
is dangerous. How it has been used
or how far it has been driven may(Continued)
Warning (Continued)
be unknown. It could fail suddenly
and cause a crash. When replacing
wheels, use a new GM original
equipment wheel.
Tire Chains
Caution
Use tire chains only where legal and
only when necessary. Use low
profile chains that add no more
than 10 mm thickness to the tire
tread and inner sidewall. Use chains
that are the proper size for the tires.
Install them on the tires of the rear
axle. Do not use chains on the tires
of the front axle. Tighten them as
tightly as possible with the ends
securely fastened. Drive slowly and
follow the chain manufacturer's
instructions. If the chains contact
the vehicle, stop and retighten
them. If the contact continues, slow(Continued)
Caution (Continued)
down until it stops. Driving too fast
or spinning the wheels with chains
on will damage the vehicle.
If a Tire Goes Flat
It is unusual for a tire to blow out
while driving, especially if the tires are
maintained properly. See Tires0339.
If air goes out of a tire, it is much
more likely to leak out slowly. But if
there ever is a blowout, here are a few
tips about what to expect and what
to do:
If a front tire fails, the flat tire creates
a drag that pulls the vehicle toward
that side. Take your foot off the
accelerator pedal and grip the steering
wheel firmly. Steer to maintain lane
position, and then gently brake to a
stop, well off the road, if possible.
A rear blowout, particularly on a
curve, acts much like a skid and may
require the same correction as used in
a skid. Stop pressing the accelerator
pedal and steer to straighten the

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
SERVICE AND MAINTENANCE 383
Maintenance Schedule
Owner Checks and Services
At Each Fuel Stop
.Check the engine oil level. See
Engine Oil 0299.
Once a Month
. Check the tire inflation pressures.
See Tire Pressure 0346.
. Inspect the tires for wear. See Tire
Inspection 0353.
. Check the windshield washer fluid
level. See Washer Fluid 0313.
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
0302.
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 Rotation0353.
. Check engine oil level and oil
life percentage. If needed, change
engine oil and filter, and reset oil
life system. See Engine Oil0299
and
Engine Oil Life System 0302. .
Inspect the engine air filter and
check the air filter life percentage.
If necessary, replace engine air
filter and reset the Engine Air
Filter Life System. See Engine Air
Cleaner/Filter 0304 and
Engine Air Filter Life System 0304.
. Check engine coolant level. See
Cooling System 0307.
. Check windshield washer fluid
level. See Washer Fluid 0313.
. Check tire inflation pressures. See
Tire Pressure 0346.
. Inspect tire wear. See Tire
Inspection 0353.
. Visually check for fluid leaks.
. Inspect brake system. See Exterior
Care 0372.
. Visually inspect steering,
suspension, and chassis
components for damage, including
cracks or tears in the rubber boots,
loose or missing parts, or signs of
wear at least once a year. See
Exterior Care 0372.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
SERVICE AND MAINTENANCE 385
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. 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. (4.2L Engine
Only) (4)@@@@@
Replace engine air cleaner filter. (Except 4.2L
Engine) (5)@ @@
Replace spark plugs. Inspect spark plug wires.
(Except 3.6L Engine)@ @
Replace spark plugs. Inspect spark plug wires. (3.6L
Engine Only)@
Drain and fill engine cooling system. (6)@
Change transfer case fluid, if equipped with
AWD. (7)@
Change rear axle fluid. (Except V-Series)@
Replace rear axle fluid. (V-Series Only)@@@
Visually inspect accessory drive belts. (8)@
Replace brake fluid. (9)
Replace windshield wiper blades. (10)
@ @ @ @ @ @ @ @ @ @
Replace hood and/or body lift support gas struts.@ @

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
386 SERVICE AND MAINTENANCE
Footnotes—Maintenance Schedule
Additional Required Services -
Normal
(1) Vehicles with different size front
and rear tires do not have tire
rotation. See Tire Rotation0353.
(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 airf low, window
fogging, or odors. Your GM dealer can
help determine when to replace the
filter. (3)
Visually check all fuel and vapor
lines and hoses for proper attachment,
connection, routing, and condition.
(4) Or every three years, whichever
comes first. If driving in dusty
conditions, inspect the filter at each
oil change or more often as needed.
(5) Or every four years, whichever
comes first. If driving in dusty
conditions, inspect the filter at each
oil change or more often as needed.
(6) Or every five years, whichever
comes first. See Cooling System0307.
(7) Do not directly power wash the
transfer case and/or front/rear axle
output seals. High pressure water can
overcome the seals and contaminate
the transfer case fluid. Contaminated
fluid will decrease the life of the
transfer case and/or axles and should
be replaced. (8)
Or every 10 years, whichever
comes first. Inspect for fraying,
excessive cracking, or damage; replace,
if needed.
(9) Replace brake fluid every five
years for DOT 3 fluid or every three
years for DOT 4 fluid. See Brake Fluid
0 315.
(10) Or every 12 months, whichever
comes first. See Wiper Blade
Replacement 0319.