check engine light CADILLAC CT6 2020 User Guide

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
130 INSTRUMENTS AND CONTROLS
For vehicles with the Tire Pressure
Monitor System (TPMS), this light
comes on briefly when the engine is
started. It provides information about
tire pressures and the TPMS.
When the Light Is On Steady
This indicates that one or more of the
tires are significantly underinflated.
A Driver Information Center (DIC) tire
pressure message may also display.
Stop as soon as possible, and inflate
the tires to the pressure value shown
on the Tire and Loading Information
label. SeeTire Pressure 0322.
When the Light Flashes First and
Then Is On Steady
If the light flashes for about a minute
and then stays on, there may be a
problem with the TPMS. If the
problem is not corrected, the light will
come on at every ignition cycle. See
Tire Pressure Monitor Operation 0325.Engine Oil Pressure Light
Caution
Lack of proper engine oil
maintenance can damage the
engine. Driving with the engine oil
low can also damage the engine.
The repairs would not be covered
by the vehicle warranty. Check the
oil level as soon as possible. Add oil
if required, but if the oil level is
within the operating range and the
oil pressure is still low, have the
vehicle serviced. Always follow the
maintenance schedule for changing
engine oil.
This light should come on briefly as
the engine is started. If it does not
come on, have the vehicle serviced by
your dealer. If the light comes on and stays on, it
means that oil is not flowing through
the engine properly. The vehicle could
be low on oil and might have some
other system problem. See your dealer.
Low Fuel Warning Light
This light is near the fuel gauge and
comes on briefly when the ignition is
turned on as a check to show it is
working. For vehicles with a
reconfigurable cluster, this light is in
the display area and may not come on
when the ignition is turned on.
It also comes on when the fuel tank is
low on fuel. The light turns off when
fuel is added. If it does not, have the
vehicle serviced.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
138 INSTRUMENTS AND CONTROLS
vehicles. The compass heading is
displayed when navigation routing is
not active.
Navigation Turn-by-Turn Alerts
shown in the instrument cluster may
also be displayed in any HUD view.
Metric
English
Performance View : This display
includes the information in the speed
view, along with rpm reading,
transmission positions, and gear shift
indicator, if equipped. The shift timing lights at the top of
the display will appear with increases
in engine rpm. The rows of lights get
closer together as the shift point gets
closer. Shift the transmission before
the lights come together in the
display. Shift immediately if the lights
are flashing. See
Manual Mode0197.
Care of the HUD
Clean the inside of the windshield to
remove any dirt or film that could
reduce the sharpness or clarity of the
HUD image.
Clean the HUD lens with a soft cloth
sprayed with glass cleaner. Wipe the
lens gently, then dry it.
HUD Troubleshooting
If the HUD image cannot be seen
when the ignition is on, check that:
.
Nothing is covering the HUD lens.
. The HUD brightness setting is not
too dim or too bright.
. The HUD is adjusted to the proper
height.
. Polarized sunglasses are not worn.
. The windshield and HUD lens are
clean.
If the HUD image is not correct,
contact your dealer.
The windshield is part of the HUD
system. If the windshield needs
replacing, see Windshield Replacement
0 295.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/14/19
DRIVING AND OPERATING 187
.The driver door has been opened
or driver seat belt has been
unbuckled.
. The hood has been opened.
. The Auto Stop has reached the
maximum allowed time.
Auto Stop Disable Switch
The automatic engine Stop/Start
function can be disabled by
touching
hon the center stack. Auto
Stop is enabled each time you start
the vehicle.
When the light next to the
his
illuminated, the system is enabled.
Engine Heater
Vehicles with the engine heater can
use this option in cold weather
conditions at or below −18 °C (0 °F) for
easier starting and better fuel
economy during engine warm-up. Plug
in the coolant heater at least four
hours before starting your vehicle. An
internal thermostat in the plug-end of
the cord may exist which will prevent
engine heater operation at
temperatures above −18 °C (0 °F).
{Warning
Do not plug in the engine block
heater while the vehicle is parked in
a garage or under a carport.
Property damage or personal injury
may result. Always park the vehicle
in a clear open area away from
buildings or structures.
To Use the Engine Heater
1. Turn off the engine. 2. Open the hood and unwrap the
electrical cord. The cord is
clipped to the diagonal brace on
the passenger side of the engine
compartment.
Check the heater cord for
damage. If it is damaged, do not
use it. See your dealer for a
replacement. Inspect the cord for
damage yearly.
3. Plug it into a normal, grounded 110-volt AC outlet.
{Warning
Improper use of the heater cord or
an extension cord can damage the
cord and may result in overheating
and fire.
. Plug the cord into a
three-prong electrical utility
receptacle that is protected by
a ground fault detection
(Continued)

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/14/19
DRIVING AND OPERATING 199
Drive Systems
All-Wheel Drive
Vehicles with this feature always send
engine power to all four wheels. It is
fully automatic, and adjusts itself as
needed for road conditions.
Brakes
Electric Brake Boost
Vehicles equipped with electric brake
boost have hydraulic brake circuits
that are electronically controlled when
the brake pedal is applied during
normal operation. The system
performs routine tests and turns off
within a few minutes after the vehicle
is shutdown. Noise may be heard
during this time. If the brake pedal is
pressed during the tests or when the
electric brake boost system is off, a
noticeable change in pedal force and
travel may be felt. This is normal.
Antilock Brake
System (ABS)
The Antilock Brake System (ABS)
helps prevent a braking skid and
maintain steering while braking hard.
ABS performs a system check when
the vehicle is first driven.
A momentary motor or clicking noisemay be heard while this test is going
on, and the brake pedal may move
slightly. This is normal.
If there is a problem with ABS, this
warning light stays on. See
Antilock
Brake System (ABS) Warning Light
0 126.
ABS does not change the time needed
to get a foot on the brake pedal and
does not always decrease stopping
distance. If you get too close to the
vehicle ahead, there will not be
enough time to apply the brakes if
that vehicle suddenly slows or stops.
Always leave enough room ahead to
stop, even with ABS.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/14/19
200 DRIVING AND OPERATING
Using ABS
Do not pump the brakes. Just hold the
brake pedal down firmly and let ABS
work. You may hear the ABS pump or
motor operating and feel the brake
pedal pulsate. This is normal.
When ABS is active, it may be an
indication that road surfaces are
slippery. Braking sooner may be
required for driving conditions.
If equipped with electric brake boost,
the TCS/StabiliTrak/ESC light will
flash when ABS is active.
Braking in Emergencies
ABS allows steering and braking at the
same time. In many emergencies,
steering can help even more than
braking.
Electric Parking Brake
The vehicle has an Electric Parking
Brake (EPB). The EPB can always be
activated, even if the ignition is off. To
prevent draining the battery, avoid
repeated cycles of the EPB system
when the engine is not running.
The system has a
Yor PARK
Electric Parking Brake light, and a
8
Service Parking Brake light. See
Electric Parking Brake Light 0125 and
Service Electric Parking Brake Light
0 126. Before leaving the vehicle, check for
the
Yor PARK light to ensure that
the parking brake is applied.
EPB Apply
To apply the EPB:
1. Be sure the vehicle is at a complete stop.
2. Press the EPB switch momentarily.
The
Yor PARK light will flash and
then stay on once the EPB is fully
applied. If the
Yor PARK light
flashes continuously, then the EPB is
only partially applied or there is a
problem with the EPB. A DIC message
will display. Release the EPB and try
to apply it again. If the light does not
come on, or keeps flashing, have the
vehicle serviced. Do not drive the
vehicle if the
Yor PARK light is
flashing. See your dealer. See Electric
Parking Brake Light 0125.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/14/19
DRIVING AND OPERATING 203
Ride Control Systems
Traction Control/Electronic
Stability Control
System Operation
The vehicle has a Traction Control
System (TCS) and StabiliTrak/
Electronic Stability Control (ESC).
These systems help limit wheel spin
and assist the driver in maintaining
control, especially on slippery road
conditions.
TCS activates if it senses that any of
the drive wheels are spinning or
beginning to lose traction. When this
happens, TCS applies the brakes to the
spinning wheels and reduces engine
power to limit wheel spin.
StabiliTrak/ESC activates when the
vehicle senses a difference between
the intended path and the direction
the vehicle is actually traveling.
StabiliTrak/ESC selectively applies
braking pressure to any one of the
vehicle wheel brakes to assist the
driver in keeping the vehicle on the
intended path.If cruise control is being used and
traction control or StabiliTrak/ESC
begins to limit wheel spin, cruise
control will disengage. Cruise control
may be turned back on when road
conditions allow.
Both systems come on automatically
when the vehicle is started and begins
to move. The systems may be heard or
felt while they are operating or while
performing diagnostic checks. This is
normal and does not mean there is a
problem with the vehicle.
It is recommended to leave both
systems on for normal driving
conditions, but it may be necessary to
turn TCS off if the vehicle gets stuck
in sand, mud, ice, or snow. See
If the
Vehicle Is Stuck 0179 and “Turning
the Systems Off and On ”later in this
section.
The indicator light for both systems is
in the instrument cluster. This
light will:
. Flash when TCS is limiting
wheel spin.
. Flash when StabiliTrak/ESC is
activated.
. Turn on and stay on when either
system is not working.
If either system fails to turn on or to
activate, a message displays in the
Driver Information Center (DIC), and
dcomes on and stays on to indicate
that the system is inactive and is not
assisting the driver in maintaining
control. The vehicle is safe to drive,
but driving should be adjusted
accordingly.
If
dcomes on and stays on:
1. Stop the vehicle.
2. Turn the engine off and wait 15 seconds.
3. Start the engine.
4. Drive the vehicle.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/14/19
DRIVING AND OPERATING 269
Conversions and
Add-Ons
Add-On Electrical
Equipment
{Warning
The Data Link Connector (DLC) is
used for vehicle service and
Emission Inspection/Maintenance
testing. SeeMalfunction Indicator
Lamp (Check Engine Light) 0123.
A device connected to the DLC —
such as an aftermarket fleet or
driver-behavior tracking device —
may interfere with vehicle systems.
This could affect vehicle operation
and cause a crash. Such devices
may also access information stored
in the vehicle’s systems.
Caution
Some electrical equipment can
damage the vehicle or cause
components to not work and would
not be covered by the vehicle
warranty. Always check with your
dealer before adding electrical
equipment.
Add-on equipment can drain the
vehicle's 12-volt battery, even if the
vehicle is not operating.
The vehicle has an airbag system.
Before attempting to add anything
electrical to the vehicle, see Servicing
the Airbag-Equipped Vehicle 075 and
Adding Equipment to the
Airbag-Equipped Vehicle 076.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-13566829) -
2020 - CRC - 6/11/19
270 VEHICLE CARE
Vehicle Care
General Information
General Information . . . . . . . . . . . . . 271
California Proposition65 Warning . . . . . . . . . . . . . . . . . . . . . 271
California Perchlorate Materials Requirements . . . . . . . . . . . . . . . . . . . 272
Accessories and Modifications . . . . . . . . . . . . . . . . . . . 272
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . . . . . . 272
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . . . . . . 274
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . 277
Engine Oil Life System . . . . . . . . . . . 280
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281
Engine Air Filter Life System . . . . 281
Engine Air Cleaner/Filter . . . . . . . . . 282
Cooling System . . . . . . . . . . . . . . . . . . . 284
Engine Overheating . . . . . . . . . . . . . . 288
Washer Fluid . . . . . . . . . . . . . . . . . . . . . 289
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290
Brake Pad Life System . . . . . . . . . . . 291
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . 291 Battery - North America . . . . . . . . . 292
All-Wheel Drive . . . . . . . . . . . . . . . . . . 293
Starter Switch Check . . . . . . . . . . . . . 294
Park Brake and P (Park)
Mechanism Check . . . . . . . . . . . . . . 294
Wiper Blade Replacement . . . . . . . 295
Windshield Replacement . . . . . . . . 295
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . 296
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . 297
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . 297
LED Lighting . . . . . . . . . . . . . . . . . . . . . 297
Electrical System
Electrical System Overload . . . . . . 298
Fuses and Circuit Breakers . . . . . . 298
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299
Instrument Panel Fuse Block . . . . 306
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315
All-Season Tires . . . . . . . . . . . . . . . . . . 316
Winter Tires . . . . . . . . . . . . . . . . . . . . . . 316
Low-Profile Tires . . . . . . . . . . . . . . . . . 317
Summer Tires . . . . . . . . . . . . . . . . . . . . 317
Tire Sidewall Labeling . . . . . . . . . . . 317 Tire Designations . . . . . . . . . . . . . . . . . 319
Tire Terminology and
Definitions . . . . . . . . . . . . . . . . . . . . . . 320
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . 322
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . . . . . . 324
Tire Pressure Monitor System . . . 324
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . . . . . . 325
Tire Inspection . . . . . . . . . . . . . . . . . . . 329
Tire Rotation . . . . . . . . . . . . . . . . . . . . . 329
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
Buying New Tires . . . . . . . . . . . . . . . . 331
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . . . . . 333
Uniform Tire Quality Grading . . . 333
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . . . . . . 334
Wheel Replacement . . . . . . . . . . . . . . 335
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . 335
If a Tire Goes Flat . . . . . . . . . . . . . . . . 336
Tire Changing . . . . . . . . . . . . . . . . . . . . . 337
Compact Spare Tire . . . . . . . . . . . . . . 342Jump Starting
Jump Starting - North America . . . . . . . . . . . . . . . . . . . . . . . . . 343

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
VEHICLE CARE 289
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 0274 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)