
Cadillac CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
CRC - 6/21/16
DRIVING AND OPERATING 189
{Warning
Using the brakes to slow the vehicle
on a long downhill slope can cause
brake overheating, can reduce brake
performance, and could result in a
loss of braking. Shift the
transmission to a lower gear to let
the engine assist the brakes on a
steep downhill slope.
{Warning
Coasting downhill in N (Neutral) or
with the ignition off is dangerous.
This can cause overheating of the
brakes and loss of steering. Always
have the engine running and the
vehicle in gear.
. Drive at speeds that keep the
vehicle in its own lane. Do not
swing wide or cross the
center line.
. Be alert on top of hills; something
could be in your lane (e.g., stalled
car, accident). .
Pay attention to special road signs
(e.g., falling rocks area, winding
roads, long grades, passing or
no-passing zones) and take
appropriate action.
Winter Driving
Driving on Snow or Ice
Snow or ice between the tires and the
road creates less traction or grip, so
drive carefully. Wet ice can occur at
about 0 °C (32 °F) when freezing rain
begins to fall. Avoid driving on wet ice
or in freezing rain until roads can be
treated.
For slippery road driving:
.Accelerate gently. Accelerating too
quickly causes the wheels to spin
and makes the surface under the
tires slick.
. Turn on Traction Control. See
Traction Control/Electronic Stability
Control 0208.
. Antilock Brake System (ABS)
improves vehicle stability during
hard stops, but the brakes should be applied sooner than when on
dry pavement. See
Antilock Brake
System (ABS) 0205.
See Driver Mode Control 0209
. Allow greater following distance
and watch for slippery spots. Icy
patches can occur on otherwise
clear roads in shaded areas. The
surface of a curve or an overpass
can remain icy when the
surrounding roads are clear. Avoid
sudden steering maneuvers and
braking while on ice.
. Turn off cruise control.
Blizzard Conditions
Stop the vehicle in a safe place and
signal for help. Stay with the vehicle
unless there is help nearby. Get help
and keep everyone in the vehicle safe:
.Turn on the hazard warning
flashers.
. Tie a red cloth to an outside
mirror.

Cadillac CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
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244 VEHICLE CARE
Vehicle Care
General Information
General Information . . . . . . . . . . . . . 245
Accessories andModifications . . . . . . . . . . . . . . . . . . . 245
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . . . . . . 245
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . . . . . . 247
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . 250
Engine Oil Life System . . . . . . . . . . . 252
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253
Engine Air Cleaner/Filter . . . . . . . . . 254
Cooling System . . . . . . . . . . . . . . . . . . . 255
Engine Coolant . . . . . . . . . . . . . . . . . . . 256
Engine Overheating . . . . . . . . . . . . . . 259
Washer Fluid . . . . . . . . . . . . . . . . . . . . . 260
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . 262
Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
All-Wheel Drive . . . . . . . . . . . . . . . . . . 264
Starter Switch Check . . . . . . . . . . . . . 264
Automatic Transmission Shift Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264 Park Brake and P (Park)
Mechanism Check . . . . . . . . . . . . . . 265
Wiper Blade Replacement . . . . . . . 265
Windshield Replacement . . . . . . . . 266
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . . . . . 266
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . 267
LED Lighting . . . . . . . . . . . . . . . . . . . . . 267
License Plate Lamp . . . . . . . . . . . . . . 267
Replacement Bulbs . . . . . . . . . . . . . . . 267
Electrical System
Electrical System Overload . . . . . . 268
Fuses and Circuit Breakers . . . . . . 269
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269
Instrument Panel Fuse Block . . . . 272
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
All-Season Tires . . . . . . . . . . . . . . . . . . 277
Winter Tires . . . . . . . . . . . . . . . . . . . . . . 277
Low-Profile Tires . . . . . . . . . . . . . . . . . 278
Summer Tires . . . . . . . . . . . . . . . . . . . . 278
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . 279
Tire Pressure for High-SpeedOperation . . . . . . . . . . . . . . . . . . . . . . . . 280 Tire Pressure Monitor System . . . 280
Tire Pressure Monitor
Operation . . . . . . . . . . . . . . . . . . . . . . . . 281
Tire Inspection . . . . . . . . . . . . . . . . . . . 284
Tire Rotation . . . . . . . . . . . . . . . . . . . . . 284
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286
Buying New Tires . . . . . . . . . . . . . . . . 286
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . . . . . 288
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . . . . . . 288
Wheel Replacement . . . . . . . . . . . . . . 288
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . 289
If a Tire Goes Flat . . . . . . . . . . . . . . . . 289
Tire Changing . . . . . . . . . . . . . . . . . . . . . 291
Compact Spare Tire . . . . . . . . . . . . . . 295
Jump Starting
Jump Starting . . . . . . . . . . . . . . . . . . . . . 296
Towing the Vehicle
Towing the Vehicle . . . . . . . . . . . . . . . 299
Recreational Vehicle Towing . . . . 299
Appearance Care
Exterior Care . . . . . . . . . . . . . . . . . . . . . . 301
Interior Care . . . . . . . . . . . . . . . . . . . . . . 305
Floor Mats . . . . . . . . . . . . . . . . . . . . . . . . 308

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256 VEHICLE CARE
{Warning
Heater and radiator hoses, and
other engine parts, can be very hot.
Do not touch them. If you do, you
can be burned.
Do not run the engine if there is a
leak. If you run the engine, it could
lose all coolant. That could cause
an engine fire, and you could be
burned. Get any leak fixed before
you drive the vehicle.
Caution
Using coolant other than
DEX-COOL®can cause premature
engine, heater core, or radiator
corrosion. In addition, the engine
coolant could require changing
sooner. Any repairs would not be
covered by the vehicle warranty.
Always use DEX-COOL (silicate-free)
coolant in the vehicle.
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 0311.
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 0259.
What to Use
{Warning
Adding 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
(Continued)
Warning (Continued)
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.

Cadillac CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
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VEHICLE CARE 257
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

Cadillac CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
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VEHICLE CARE 259
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.
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.
Caution
If 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 0124 and
Engine Coolant Temperature Warning
Light 0132. The vehicle may also
display a message on the Driver
Information Center (DIC). See Engine
Cooling System Messages 0143.
If the decision is made not to lift the
hood when this warning appears, get
service help right away.
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
{Warning
Steam 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.

Cadillac CT6 Owner Manual (GMNA-Localizing-MidEast-10293390) - 2017 -
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268 VEHICLE CARE
Electrical System
Electrical System Overload
The vehicle has fuses and circuit
breakers to protect against an
electrical system overload.
When the current electrical load is too
heavy, the circuit breaker opens and
closes, protecting the circuit until the
current load returns to normal or the
problem is fixed. This greatly reduces
the chance of circuit overload and fire
caused by electrical problems.
Fuses and circuit breakers protect
power devices in the vehicle.
Replace a bad fuse with a new one of
the identical size and rating.If there is a problem on the road and
a fuse needs to be replaced, the
same amperage fuse can be borrowed.
Choose some feature of the vehicle
that is not needed to use and replace
it as soon as possible.
Headlamp Wiring
An electrical overload may cause the
lamps to go on and off, or in some
cases to remain off. Have the
headlamp wiring checked right away if
the lamps go on and off or remain off.
Windshield Wipers
If the wiper motor overheats due to
heavy snow or ice, the windshield
wipers will stop. Wiper function is
available immediately after the wiper
switch is set to off, and back to on.To protect the wiper motor from
overheating, the wipers may slow
down when the windshield is dry for a
long period of time. If a period of dry
operation, or little moisture, exceeds
10 minutes, the wipers may switch to
intermittent operation, and remain
there. When moisture is again
detected on the windshield, wiper
operation will return to the operator
selected speed.
Although the circuit is protected from
electrical overload, overload due to
heavy snow or ice may cause wiper
linkage damage. Always clear ice and
heavy snow from the windshield
before using the windshield wipers.
If the overload is caused by an
electrical problem and not snow or
ice, be sure to get it fixed.

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276 VEHICLE CARE
FuseUsage
F57 Voltage current temperature module
F58 –
F59 Engine control module battery
F60 Right motorized safety belt
pretensioner
F61 Parking lamps
F62 –
F63 –
F64 Engine control module ignition
F65 Rear window sunshade
F66 Rear vision camera/ Interior rearview
mirror
F67 DC DC converter/Air quality sensor
F68 Damping control module Fuse
Usage
F69 Television tuner module
F70 –
F71 –
F72 –
F73 –
F74 –
F75 –
Relays Usage
R1 Rear seat power outlet relay
R2 Fuel pump relay
R3 Run/Crank relayWheels and Tires
Tires
Every new GM vehicle has
high-quality tires made by a
leading tire manufacturer. See the
warranty manual for information
regarding the tire warranty and
where to get service. For
additional information refer to the
tire manufacturer.
{Warning
.Poorly maintained and
improperly used tires are
dangerous.
.Overloading the tires can
cause overheating as a
result of too much flexing.
There could be a blowout
and a serious crash. See
Vehicle Load Limits 0191.
(Continued)

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VEHICLE CARE 279
Caution (Continued)
directly on the tires. Always inspect
tires before use. SeeTire
Inspection 0284.
Tire Pressure
Tires need the correct amount of
air pressure to operate effectively.
Caution
Neither tire underinflation nor
overinflation is good.
Underinflated tires, or tires that
do not have enough air, can
result in:
.Tire overloading and
overheating which could
lead to a blowout.
.Premature or
irregular wear.
.Poor handling.
.Reduced fuel economy.
(Continued)
Caution (Continued)
Overinflated tires, or tires that
have too much air, can result in:
.Unusual wear.
.Poor handling.
.Rough ride.
.Needless damage from
road hazards.
The Tire and Loading Information
label on the vehicle indicates the
original equipment tires and the
correct cold tire inflation
pressures. The recommended
pressure is the minimum air
pressure needed to support the
vehicle's maximum load carrying
capacity. See Vehicle Load
Limits 0191.
How the vehicle is loaded affects
vehicle handling and ride comfort.
Never load the vehicle with more
weight than it was designed to
carry. When to Check
Check the tires once a month or
more. Do not forget the compact
spare, if the vehicle has one. The
cold compact spare tire pressure
should be at 420 kPa (60 psi). See
Compact Spare Tire
0295.
How to Check
Use a good quality pocket-type
gauge to check tire pressure.
Proper tire inflation cannot be
determined by looking at the tire.
Check the tire inflation pressure
when the tires are cold, meaning
the vehicle has not been driven for
at least three hours or no more
than 1.6 km (1 mi).
Remove the valve cap from the
tire valve stem. Press the tire
gauge firmly onto the valve to get
a pressure measurement. If the
cold tire inflation pressure
matches the recommended
pressure on the Tire and Loading
Information label, no further
adjustment is necessary. If the