
Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
288 VEHICLE CARE
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 engine
damage may occur. Be sure the cap
is properly and tightly secured.
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 0119 and
Engine Coolant Temperature Warning
Light 0129. 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 0380.
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-13566829) -
2020 - CRC - 6/11/19
298 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 wiperlinkage 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.
Fuses and Circuit Breakers
The wiring circuits in the vehicle are
protected from short circuits by a
combination of fuses and circuit
breakers. This greatly reduces the
chance of damage caused by electrical
problems.
{Danger
Fuses and circuit breakers are
marked with their ampere rating.
Do not exceed the
specified amperage rating when
replacing fuses and circuit breakers.
Use of an oversized fuse or circuit
breaker can result in a vehicle fire.
You and others could be seriously
injured or killed.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
VEHICLE CARE 315
RelaysUsage
R01 Rear seat auxiliary power outlet
R02 Spare
R03 Run/CrankWheels 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 0179.
(Continued)
Warning (Continued)
.Underinflated tires pose
the same danger as
overloaded tires. The
resulting crash could cause
serious injury. Check all
tires frequently to
maintain the
recommended pressure.
Tire pressure should be
checked when the tires
are cold.
.Overinflated tires are more
likely to be cut, punctured,
or broken by a sudden
impact —such as when
hitting a pothole. Keep
tires at the recommended
pressure.
.Worn or old tires can
cause a crash. If the tread
is badly worn,
replace them.
(Continued)

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
VEHICLE CARE 323
{Warning
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.
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
0 179.
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 pressure of 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 0342. 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
inflation pressure is low, add air
until the recommended pressure is
reached. If the inflation pressure
is high, press on the metal stem in
the center of the tire valve to
release air.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
INDEX 403
Driving (cont'd)Off-Road Recovery . . . . . . . . . . . . . . . . 175
Track Events and Competitive . . . 176
Vehicle Load Limits . . . . . . . . . . . . . . 179
Wet Roads . . . . . . . . . . . . . . . . . . . . . . . . . 176
Winter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
E
Electric Brake Boost . . . . . . . . . . . . . . . . 199
Electric Parking Brake . . . . . . . . . . . . . . 200
Electric Parking Brake Light . . . . . . . 125
Electrical Equipment, Add-On . . . . . 269
Electrical System
Engine Compartment Fuse
Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299
Fuses and Circuit Breakers . . . . . . . 298
Instrument Panel Fuse Block . . . . 306
Overload . . . . . . . . . . . . . . . . . . . . . . . . . . . 298
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308
Emergency OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 391
Engine Air Cleaner/Filter . . . . . . . . . . . . . . . . . 282
Check Light (Malfunction
Indicator) . . . . . . . . . . . . . . . . . . . . . . . . 123
Compartment Overview . . . . . . . . . . 274
Coolant Temperature Gauge . . . . . 119 Engine (cont'd)
Coolant Temperature
Warning Light . . . . . . . . . . . . . . . . . . . 129
Cooling System . . . . . . . . . . . . . . . . . . . 284
Drive Belt Routing . . . . . . . . . . . . . . . . 375
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192
Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
Oil Life System . . . . . . . . . . . . . . . . . . . . 280
Oil Pressure Gauge . . . . . . . . . . . . . . . . 117
Oil Pressure Light . . . . . . . . . . . . . . . . . 130
Overheating . . . . . . . . . . . . . . . . . . . . . . . 288
Power Messages . . . . . . . . . . . . . . . . . . 139
Running While Parked . . . . . . . . . . . 192
Starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
Engine Air Filter Life System . . . . . . 281
Engine Oil Temperature Gauge . . . . . . . . . . . . . . . 118
Entry Lighting . . . . . . . . . . . . . . . . . . . . . . 155
Equipment, Towing . . . . . . . . . . . . . . . . . 267
Event Data Recorders . . . . . . . . . . . . . . 388
Exit Lighting . . . . . . . . . . . . . . . . . . . . . . . . 155
Extended Parking . . . . . . . . . . . . . . . . . . . 191
Extender, Seat Belt . . . . . . . . . . . . . . . . . . 64
Exterior Lamp Controls . . . . . . . . . . . . 149
Exterior Lamps Off Reminder . . . . . . 151
Exterior Lighting Battery Saver . . . . 156
F
Filter,
Engine Air Cleaner . . . . . . . . . . . . . . . . 282
Flash-to-Pass . . . . . . . . . . . . . . . . . . . . . . . . 151
Flashers, Hazard Warning . . . . . . . . . . 152
Flat Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336 Changing . . . . . . . . . . . . . . . . . . . . . . . . . . 337
Floor Mats . . . . . . . . . . . . . . . . . . . . . . . . . . . 356
Fluid Automatic Transmission . . . . . . . . . 281
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291
Washer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289
Folding Mirrors . . . . . . . . . . . . . . . . . . . . . . 33
Forward Collision Alert (FCA) System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244
Frequency Statement Radio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 386
Front Pedestrian Braking (FPB) System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
Front Seats Heated and Ventilated . . . . . . . . . . . . . 51
Fuel Additives . . . . . . . . . . . . . . . . . . . . . . . . . . 259
Economy, Driving for Better . . . . . 172
Filling a Portable FuelContainer . . . . . . . . . . . . . . . . . . . . . . . . 261
Filling the Tank . . . . . . . . . . . . . . . . . . . 260
Foreign Countries . . . . . . . . . . . . . . . . . 259

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
406 INDEX
Locks (cont'd)Door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Lockout Protection . . . . . . . . . . . . . . . . . 22
Power Door . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Loss of Control . . . . . . . . . . . . . . . . . . . . . . 175
Low Fuel Warning Light . . . . . . . . . . . 130
Low-Profile Tires . . . . . . . . . . . . . . . . . . . . 317
Lower Anchors and Tethers for Children (LATCH System) . . . . . . . . . 84
Lumbar Adjustment . . . . . . . . . . . . . 46, 55 Front Seats . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Rear Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
M
MaintenanceRecords . . . . . . . . . . . . . . . . . . . . . . . . . . . . 371
Maintenance and Care Additional . . . . . . . . . . . . . . . . . . . . . . . . . 365
Maintenance Schedule . . . . . . . . . . . . . 359 Recommended Fluids andLubricants . . . . . . . . . . . . . . . . . . . . . . . 368
Malfunction Indicator Lamp . . . . . . . 123
Manual Mode . . . . . . . . . . . . . . . . . . . . . . . 197
Massage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Memory Seats . . . . . . . . . . . . . . . . . . . . . . . . 48
Messages Engine Power . . . . . . . . . . . . . . . . . . . . . 139 Messages (cont'd)
Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Vehicle Speed . . . . . . . . . . . . . . . . . . . . . 139
Mirror
Rear Camera . . . . . . . . . . . . . . . . . . . . . . . . 35
Mirrors Automatic Dimming . . . . . . . . . . . . . . . . 34
Automatic Dimming Rearview . . . . . 35
Convex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Folding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Heated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Tilt in Reverse . . . . . . . . . . . . . . . . . . . . . . 34
Mirrors, Interior Rearview . . . . . . . . . . . 35
Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
Driver Control . . . . . . . . . . . . . . . . . . . . . 204
Monitor System, Tire Pressure . . . . . 324
N
Navigation Connected Services . . . . . . . . . . . . . . . 397
Net, Convenience . . . . . . . . . . . . . . . . . . . 101
New Vehicle Break-In . . . . . . . . . . . . . . . 183
Night Vision System . . . . . . . . . . . . . . . . 250
O
Odometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 Trip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 Off-Road
Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
Oil Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
Engine Oil Life System . . . . . . . . . . . 280
Engine Oil Pressure Gauge . . . . . . . 117
Pressure Light . . . . . . . . . . . . . . . . . . . . . 130
Older Children, Restraints . . . . . . . . . . . 77
Online Owner Center . . . . . . . . . . . . . . . 379
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 388
OnStar Additional Information . . . . 392
OnStar Emergency . . . . . . . . . . . . . . . . . . 391
OnStar Overview . . . . . . . . . . . . . . . . . . . . 390
OnStar Security . . . . . . . . . . . . . . . . . . . . . 391
Outlets Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Overheating, Engine . . . . . . . . . . . . . . . . 288
Overview Instrument Panel . . . . . . . . . . . . . . . . . . . . 5
P
ParkShifting Out of . . . . . . . . . . . . . . . . . . . . 189
Park Assist . . . . . . . . . . . . . . . . . . . . . . . . . . 235
Parking Brake and P (Park)
Mechanism Check . . . . . . . . . . . . . . . 294
Extended . . . . . . . . . . . . . . . . . . . . . . . . . . 191