
Cadillac CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
CRC - 6/21/16
254 VEHICLE CARE
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 inMaintenance
Schedule 0311, and be sure to use the
fluid listed in Recommended Fluids and
Lubricants 0318.
Engine Air Cleaner/Filter
See Engine Compartment Overview
0 247 for location.
When to Inspect the Engine Air
Cleaner/Filter
For intervals on changing and
inspecting the engine air cleaner/filter,
seeMaintenance Schedule 0311.
How to Inspect the Engine Air
Cleaner/Filter
Do not start the engine or have the
engine running with the engine air
cleaner/filter housing open. Before removing the engine air cleaner/filter,
make sure that the engine air cleaner/
filter housing and nearby components
are free of dirt and debris. Remove the
engine air cleaner/filter. Lightly tap
and shake the engine air cleaner/filter
(away from the vehicle), to release
loose dust and dirt. Inspect the engine
air cleaner/filter for damage, and
replace if damaged. Do not clean the
engine air cleaner/filter or
components with water or
compressed air.
To inspect or replace the air cleaner/
filter:3.0L V6 Engine
1. Remove the 10 screws on top of
the engine air cleaner/filter cover.
2. Lift the engine air cleaner/filter cover open on the hinge.
3. Pull out the engine air cleaner/ filter.
4. Inspect or replace the engine air cleaner/filter.
5. Reverse Steps 1–3 to reinstall the engine air cleaner/filter cover.
3.6L V6 Engine
1. Screws (6)
2. Bolts (3)
3. Diagonal Brace

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Caution
If 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. SeeRecommended Fluids
and Lubricants 0318.
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.
Checking Coolant
The vehicle must be on a level surface
when checking the coolant level.
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. 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 is cool
before this is done. See
Engine
Overheating 0259.
The coolant surge tank is in the
engine compartment on the passenger
side of the vehicle. See Engine
Compartment Overview 0247.
How to Add Coolant to the
Coolant Surge Tank
Caution
This 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 is not at the indicated
level mark, add a 50/50 mixture of

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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 0247 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.
. Do not mix water with
ready-to-use washer fluid.
Water can cause the solution
(Continued)

Cadillac CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
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VEHICLE CARE 261
Caution (Continued)
to freeze and damage the
washer fluid tank and other
parts of the washer system.
. When using concentrated
washer fluid, follow the
manufacturer instructions for
adding water.
. Fill the washer fluid tank only
three-quarters full when it is
very cold. This allows for
fluid expansion if freezing
occurs, which could damage
the tank if it is
completely full.
Brakes
Disc brake pads have built-in wear
indicators that make a high-pitched
warning sound when the brake pads
are worn and new pads are needed.
The sound can come and go or can be
heard all the time when the vehicle is
moving, except when applying the
brake pedal firmly.
{Warning
The brake wear warning sound
means that soon the brakes will not
work well. That could lead to a
crash. When the brake wear
warning sound is heard, have the
vehicle serviced.
Caution
Continuing to drive with worn-out
brake pads could result in costly
brake repair.
Some driving conditions or climates
can cause a brake squeal when the
brakes are first applied or lightly
applied. This does not mean
something is wrong with the brakes.
Properly torqued wheel nuts are
necessary to help prevent brake
pulsation. When tires are rotated,
inspect brake pads for wear and
evenly tighten wheel nuts in the proper sequence to torque
specifications. See
Capacities and
Specifications 0322.
Brake pads should be replaced as
complete sets.
Brake Pedal Travel
See your dealer if the brake pedal does
not return to normal height, or if
there is a rapid increase in pedal
travel. This could be a sign that brake
service may be required.
Replacing Brake System Parts
Always replace brake system parts
with new, approved replacement parts.
If this is not done, the brakes may not
work properly. The braking
performance expected can change in
many other ways if the wrong
replacement brake parts are installed
or if parts are improperly installed.

Cadillac CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
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Brake Fluid
The brake master cylinder reservoir is
filled with GM approved DOT 3 brake
fluid as indicated on the reservoir cap.
SeeEngine Compartment Overview
0 247 for the location of the reservoir.
Checking Brake Fluid
With the vehicle in P (Park) on a level
surface, the brake fluid level should be
between the minimum and maximum
marks on the brake fluid reservoir.
There are only two reasons why the
brake fluid level in the reservoir may
go down:
. Normal brake lining wear. When
new linings are installed, the fluid
level goes back up.
. A fluid leak in the brake hydraulic
system. Have the brake hydraulic
system fixed. With a leak, the
brakes will not work well. Always clean the brake fluid reservoir
cap and the area around the cap
before removing it.
Do not top off the brake fluid. Adding
fluid does not correct a leak. If fluid is
added when the linings are worn,
there will be too much fluid when
new brake linings are installed. Add or
remove fluid, as necessary, only when
work is done on the brake hydraulic
system.
{Warning
If too much brake fluid is added, it
can spill on the engine and burn,
if the engine is hot enough. You or
others could be burned, and the
vehicle could be damaged. Add
brake fluid only when work is done
on the brake hydraulic system.
When the brake fluid falls to a low
level, the brake warning light comes
on. See Brake System Warning
Light 0129.
Brake fluid absorbs water over time
which degrades the effectiveness of
the brake fluid. Replace brake fluid at the specified intervals to prevent
increased stopping distance. See
Maintenance Schedule
0311.
What to Add
Use only GM approved DOT 3 brake
fluid from a clean, sealed container.
See Recommended Fluids and
Lubricants 0318.
{Warning
The wrong or contaminated brake
fluid could result in damage to the
brake system. This could result in
the loss of braking leading to a
possible injury. Always use the
proper GM approved brake fluid.
Caution
If brake fluid is spilled on the
vehicle's painted surfaces, the paint
finish can be damaged. Immediately
wash off any painted surface.

Cadillac CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
CRC - 6/21/16
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Battery
The original equipment battery is
maintenance free. Do not remove the
cap and do not add fluid.
Refer to the replacement number
shown on the original battery label
when a new 12-volt battery is needed.
The battery is in the trunk under the
spare tire. The vehicle has an
Absorbed Glass Mat (AGM) 12-volt
battery. Installation of a standard
12-volt battery will result in reduced
12-volt battery life.
When using a 12-volt battery charger
on the 12-volt AGM battery, some
chargers have an AGM battery setting
on the charger. If available, use the
AGM setting on the charger, to limit
charge voltage to 14.8 volts.
Stop/Start System
The vehicle has a Stop/Start system to
shut off the engine to help conserve
fuel. SeeStarting the Engine 0196.
{Warning
Do not use a match or flame near a
vehicle's battery. If you need more
light, use a flashlight.
Do not smoke near a vehicle's
battery.
When working around a vehicle’s
battery, shield your eyes with
protective glasses.
Keep children away from vehicle
batteries.
{Warning
Batteries have acid that can burn
you and gas that can explode. You
can be hurt badly if you are not
careful.
Follow instructions carefully when
working around a battery.
Battery posts, terminals and related
accessories contain lead and lead
compounds which can cause cancer
and reproductive harm. Wash
hands after handling.
Vehicle Storage
Infrequent Usage: Remove the 12-volt
battery black, negative (−) cable from
the battery to keep the battery from
running down.
Extended Storage: Remove the 12-volt
battery black, negative (−) cable from
the battery or use a battery trickle
charger.
Remember to reconnect the battery
when ready to drive the vehicle.

Cadillac CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
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All-Wheel Drive
If the vehicle is equipped with
All-Wheel Drive (AWD), this is an
additional system that needs
lubrication.
Transfer Case
When to Check Lubricant
It is not necessary to regularly check
the transfer case fluid unless a leak is
suspected or an unusual noise is
heard. A fluid loss could indicate a
problem. Have it inspected and
repaired.
How to Check Lubricant
1. Fill Plug
2. Drain Plug
To get an accurate reading, the vehicle
should be on a level surface.
If the level is below the bottom of the
fill plug hole on the transfer case,
some lubricant will need to be added.
Add enough lubricant to raise the
level to the bottom of the fill plug
hole. Use care not to overtighten the
fill plug.
What to Use
To determine what kind of lubricant
to use, seeRecommended Fluids and
Lubricants 0318.
Starter Switch Check
{Warning
When you are doing this inspection,
the vehicle could move suddenly.
If the vehicle moves, you or others
could be injured.
1. Before starting this check, be sure there is enough room
around the vehicle. 2. Firmly apply both the parking
brake and the regular brake. Do
not use the accelerator pedal,
and be ready to turn off the
engine immediately if it starts.
3. Try to start the engine in each gear. The vehicle should start
only in P (Park) or N (Neutral).
If the vehicle starts in any other
position, contact your dealer for
service.
Automatic Transmission
Shift Lock Control Function
Check
{Warning
When you are doing this inspection,
the vehicle could move suddenly.
If the vehicle moves, you or others
could be injured.
1. Before starting this check, be sure there is enough room
around the vehicle. It should be
parked on a level surface.

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{Warning
An electric fan can start up even
when the engine is not running and
can injure you. Keep hands,
clothing, and tools away from any
underhood electric fan.
{Warning
Using a match near a battery can
cause battery gas to explode. People
have been hurt doing this, and
some have been blinded. Use a
flashlight if you need more light.
Battery fluid contains acid that can
burn you. Do not get it on you.
If you accidentally get it in your
eyes or on your skin, flush the place
with water and get medical help
immediately.
{Warning
Fans or other moving engine parts
can injure you badly. Keep your
hands away from moving parts
once the engine is running.
5. Connect one end of the red positive (+) cable to the
positive (+) terminal on the
discharged battery.
6. Connect the other end of the red positive (+) cable to the
positive (+) terminal of the good
battery.
7. Connect one end of the black negative (–) cable to the
negative (–) terminal of the good
battery.
8. Connect the other end of the black negative (–) cable to the
negative (–) grounding point for
the discharged battery.
9. Start the engine in the vehicle with the good battery and run
the engine at idle speed for at
least four minutes. 10. Try to start the vehicle that had
the dead battery. If it will not
start after a few tries, it probably
needs service.
Caution
If the jumper cables are connected
or removed in the wrong order,
electrical shorting may occur and
damage the vehicle. The repairs
would not be covered by the vehicle
warranty. Always connect and
remove the jumper cables in the
correct order, making sure that the
cables do not touch each other or
other metal.
Jumper Cable Removal
Reverse the sequence exactly when
removing the jumper cables.
After starting the disabled vehicle and
removing the jumper cables, allow it
to idle for several minutes.