2020 CADILLAC CT6 coolant level

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
102 INSTRUMENTS AND CONTROLS
Instruments and
Controls
Controls
Steering Wheel Adjustment . . . . . 103
Steering Wheel Controls . . . . . . . . . 103
Heated Steering Wheel . . . . . . . . . . 103
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
Windshield Wiper/Washer . . . . . . . 104
Compass . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Power Outlets . . . . . . . . . . . . . . . . . . . . . 106
Wireless Charging . . . . . . . . . . . . . . . . 107
Warning Lights, Gauges, and
Indicators
Warning Lights, Gauges, andIndicators . . . . . . . . . . . . . . . . . . . . . . . 109
Instrument Cluster (Base Level) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Instrument Cluster (Uplevel) . . . . 113
Speedometer . . . . . . . . . . . . . . . . . . . . . . 115
Odometer . . . . . . . . . . . . . . . . . . . . . . . . . 116
Trip Odometer . . . . . . . . . . . . . . . . . . . . 116
Tachometer . . . . . . . . . . . . . . . . . . . . . . . 116
Fuel Gauge . . . . . . . . . . . . . . . . . . . . . . . . 116 Boost Gauge (Performance
Configuration Only) . . . . . . . . . . . . 117
Engine Oil Pressure Gauge (Base Level Cluster Only) . . . . . . . . . . . . . 117
Engine Oil Temperature Gauge
(Performance
Configuration Only) . . . . . . . . . . . . 118
Engine Coolant Temperature Gauge . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
Voltmeter Gauge (Base Level Cluster Only) . . . . . . . . . . . . . . . . . . . . 120
Seat Belt Reminders . . . . . . . . . . . . . . 120
Airbag Readiness Light . . . . . . . . . . 121
Passenger Airbag Status Indicator . . . . . . . . . . . . . . . . . . . . . . . . . 121
Charging System Light . . . . . . . . . . . 122
Malfunction Indicator Lamp (Check Engine Light) . . . . . . . . . . . 123
Brake System Warning Light . . . . 125
Electric Parking Brake Light . . . . . 125
Service Electric Parking Brake Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Antilock Brake System (ABS) Warning Light . . . . . . . . . . . . . . . . . . 126
Gear Shifting Light . . . . . . . . . . . . . . . 126
Automatic Vehicle Hold (AVH) Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
Lane Keep Assist (LKA) Light . . . 127
Vehicle Ahead Indicator . . . . . . . . . 127 Pedestrian Ahead Indicator . . . . . . 127
Traction Off Light . . . . . . . . . . . . . . . . 128
StabiliTrak OFF Light . . . . . . . . . . . . 128
Traction Control System (TCS)/
StabiliTrak Light . . . . . . . . . . . . . . . . 128
Engine Coolant Temperature Warning Light . . . . . . . . . . . . . . . . . . 129
Driver Mode Control Light . . . . . . . 129
Tire Pressure Light . . . . . . . . . . . . . . . 129
Engine Oil Pressure Light . . . . . . . . 130
Low Fuel Warning Light . . . . . . . . . 130
Security Light . . . . . . . . . . . . . . . . . . . . . 131
High-Beam On Light . . . . . . . . . . . . . 131
Lamps On Reminder . . . . . . . . . . . . . 131
Cruise Control Light . . . . . . . . . . . . . . 131
Door Ajar Light . . . . . . . . . . . . . . . . . . . 132
Information Displays
Driver Information Center (DIC) . . . . . . . . . . . . . . . . . . . . . 132
Head-Up Display (HUD) . . . . . . . . . 135
Vehicle Messages
Vehicle Messages . . . . . . . . . . . . . . . . . 139
Engine Power Messages . . . . . . . . . . 139
Vehicle Speed Messages . . . . . . . . . 139
Vehicle Personalization
Vehicle Personalization . . . . . . . . . . 140

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
INSTRUMENTS AND CONTROLS 119
Engine Coolant
Temperature Gauge
Base Level Metric Standard Theme
Base Level English Standard Theme
Uplevel Metric BalancedConfiguration
Uplevel English Balanced Configuration
This gauge measures the temperature
of the vehicle's engine coolant.
While driving under normal operating
conditions, if the needle moves into
the red area, the engine is too hot.
Pull off the road, stop the vehicle, and
turn off the engine as soon as
possible.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/14/19
DRIVING AND OPERATING 265
signs, trees, or other objects. Always
signal turns well in advance. Do not
steer or brake suddenly.
Driving on Grades
Reduce speed and shift to a lower gear
before starting down a long or steep
downhill grade. If the transmission is
not shifted down, the brakes may
overheat and result in reduced braking
efficiency.
Vehicles can tow in D (Drive). Shift
the transmission to a lower gear if the
transmission shifts too often under
heavy loads and/or hilly conditions.
When towing at higher altitudes,
engine coolant will boil at a lower
temperature than at lower altitudes.
If the engine is turned off immediately
after towing at high altitude on steep
uphill grades, the vehicle could show
signs similar to engine overheating. To
avoid this, let the engine run,
preferably on level ground, with the
transmission in P (Park) for a few
minutes before turning the engine off.
If the overheat warning comes on, see
Engine Overheating0288.
Parking on Hills
{Warning
To prevent serious injury or death,
always park your vehicle and trailer
on a level surface when possible.
When parking your vehicle and your
trailer on a hill: 1. Press the brake pedal, but do not shift into P (Park) yet. Turn the
wheels into the curb if facing
downhill or into traffic if facing
uphill.
2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, release the regular brakes
until the chocks absorb the load.
4. Reapply the brake pedal. Then apply the parking brake and shift
into P (Park).
5. Release the brake pedal.
Leaving After Parking on a Hill
1. Apply and hold the brake pedal. .Start the engine.
. Shift into a gear.
. Release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
Maintenance when Trailer
Towing
The vehicle needs service more often
when used to tow trailers. See
Maintenance Schedule 0359. It is
especially important to check the
automatic transmission fluid, engine
oil, axle lubricant, belts, cooling
system, and brake system before and
during each trip.
Check periodically that all nuts and
bolts on the trailer hitch are tight.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
VEHICLE CARE 277
1. Passenger Side EngineCompartment Fuse Block. See
Engine Compartment Fuse Block
0299.
2. Engine Coolant Surge Tank and Pressure Cap. See Cooling System
0 284.
3. Passenger Side Engine Air Cleaner/Filter. See Engine Air
Cleaner/Filter 0282.
4. Engine Oil Fill Cap. See Engine Oil
0 277.
5. Engine Oil Dipstick. See Engine
Oil 0277.
6. Engine Cooling Fan (Out of View). See Cooling System 0284.
7. Driver Side Engine Air Cleaner/ Filter. See Engine Air Cleaner/
Filter 0282.
8. Remote Positive (+) Battery Terminal. See Jump Starting -
North America 0343.
9. Brake Fluid Reservoir. See Brake
Fluid 0291. 10. Windshield Washer Fluid
Reservoir. See Washer Fluid
0 289.
11. Driver Side Engine Compartment Fuse Block. See Engine
Compartment Fuse Block 0299.
12. Remote Negative (-) Battery Terminal. See Jump Starting -
North America 0343.
Engine Oil
To ensure proper engine performance
and long life, careful attention must
be paid to engine oil. Following these
simple, but important steps will help
protect your investment:
.
Use engine oil approved to the
proper specification and of the
proper viscosity grade. See
“Selecting the Right Engine Oil” in
this section.
. Check the engine oil level regularly
and maintain the proper oil level.
See “Checking Engine Oil” and
“When to Add Engine Oil” later in
this section. .
Change the engine oil at the
appropriate time. See Engine Oil
Life System 0280.
. Always dispose of engine oil
properly. See “What to Do with
Used Oil” in this section.
Checking Engine Oil
Check the engine oil level regularly,
every 650 km (400 mi), especially prior
to a long trip. The engine oil dipstick
handle is a loop. See Engine
Compartment Overview 0274 for the
location.
{Warning
The engine oil dipstick handle may
be hot; it could burn you. Use a
towel or glove to touch the dipstick
handle.
If a low oil Driver Information Center
(DIC) message displays, check the oil
level.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
VEHICLE CARE 285
4.2L V8 Engine
1. Engine Coolant Surge Tankand Pressure Cap (Under
Cover)
2. Engine Cooling Fan (Out of View)
{Warning
An underhood electric fan can start
up even when the engine is not
running and can cause injury. Keep
hands, clothing, and tools away
from any underhood electric fan. If the coolant inside the coolant surge
tank is boiling, do not do anything
else until it cools down. The vehicle
should be parked on a level surface.
The coolant level should be at the
indicated mark on the middle of the
tank. If it is not, the vehicle may have
a leak at the radiator hoses, heater
hoses, radiator, water pump,
or somewhere else in the cooling
system.
{Warning
Do not touch heater or radiator
hoses, or other engine parts. They
can be very hot and can burn you.
Do not run the engine if there is a
leak; all coolant could leak out.
That could cause an engine fire and
can burn you. Fix any leak before
driving the vehicle.
If there seems to be no leak, with the
engine on, check to see if the electric
cooling fan is running. If the engine is
overheating, the fan should be
running. If it is not, the vehicle needs
service. Turn off the engine.
Engine Coolant
The engine cooling system in the
vehicle is filled with a DEX-COOL
engine coolant mixture. This coolant
needs to be checked and replaced at
appropriate intervals. See Maintenance
Schedule 0359.
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 0288.
What to Use
{Warning
Plain water, or other liquids such as
alcohol, can boil before the proper
coolant mixture will. With plain
water or the wrong mixture, the
engine could get too hot but there
would not be an overheat warning.
The engine could catch fire and you
or others could be burned.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
286 VEHICLE CARE
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.
Caution
Do not use anything other than a
mix of DEX-COOL coolant that
meets GM Standard GMW3420 and
clean, drinkable water. Anything
else can cause damage to the
engine cooling system and the
vehicle, which would not be covered
by the vehicle warranty. 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.
3.6L V6 and 4.2L V8 Engine Coolant
Surge Tank The coolant surge tank is in the
engine compartment on the passenger
side of the vehicle. See
Engine
Compartment Overview 0274.
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
0 288.
How to Add Coolant to the
Coolant Surge Tank
If no problem is found, check to see if
coolant is visible in the coolant surge
tank. If coolant is visible but not at or
above the indicated mark, add a
50/50 mixture of clean, drinkable
water and DEX-COOL coolant. Be sure
the cooling system, including the
coolant surge tank pressure cap, is
cool before this is done. See Engine
Overheating 0288.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
VEHICLE CARE 287
{Warning
Spilling coolant on hot engine parts
can burn you. Coolant contains
ethylene glycol and it will burn if
the engine parts are hot enough.
{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.
Caution
Failure to follow the specific
coolant fill procedure could cause
the engine to overheat and could
cause system damage. If coolant is
not visible in the surge tank,
contact your dealer.
3.6L V6 Engine
1. Remove the coolant surge tankpressure 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.
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.

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.