check engine light CADILLAC CT6 2019 User Guide

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
INSTRUMENTS AND CONTROLS 155
Metric
English
Navigation View : This display
includes digital speed, indicators from
speed view, along with Turn-by-Turn
Navigation information in some
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 Mode0215.
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
0 319.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
194 DRIVING AND OPERATING
these types of driving conditions and
avoid driving through large puddles
and deep-standing or flowing water.
{Warning
Wet brakes can cause crashes. They
might not work as well in a quick
stop and could cause pulling to one
side. You could lose control of the
vehicle.
After driving through a large puddle
of water or a car/vehicle wash,
lightly apply the brake pedal until
the brakes work normally.
Flowing or rushing water creates
strong forces. Driving through
flowing water could cause the
vehicle to be carried away. If this
happens, you and other vehicle
occupants could drown. Do not
ignore police warnings and be very
cautious about trying to drive
through flowing water.
Hydroplaning
Hydroplaning is dangerous. Water can
build up under the vehicle's tires so
they actually ride on the water. This
can happen if the road is wet enough
and you are going fast enough. When
the vehicle is hydroplaning, it has
little or no contact with the road.
There is no hard and fast rule about
hydroplaning. The best advice is to
slow down when the road is wet.
Other Rainy Weather Tips
Besides slowing down, other wet
weather driving tips include:
.Allow extra following distance.
. Pass with caution.
. Keep windshield wiping equipment
in good shape.
. Keep the windshield washer fluid
reservoir filled.
. Have good tires with proper tread
depth. See Tires0339.
. Turn off cruise control.
Hill and Mountain Roads
Driving on steep hills or through
mountains is different than driving on
flat or rolling terrain. Tips include:
.Keep the vehicle serviced and in
good shape.
. Check all fluid levels and brakes,
tires, cooling system, and
transmission.
. Shift to a lower gear when going
down steep or long hills.
{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.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
DRIVING AND OPERATING 201
.Do not participate in track events,
sport driving schools, or similar
activities during this break-in
period.
. Check engine oil with every
refueling and add if necessary. Oil
and fuel consumption may be
higher than normal during the
first 2 400 km (1,500 mi).
. To break in new tires, drive at
moderate speeds and avoid hard
cornering for the first
300 km (200 mi). New tires do not
have maximum traction and may
tend to slip.
. New brake linings also need a
break–in period. Avoid making
hard stops during the first
300 km (200 mi). This is
recommended every time brake
linings are replaced.Ignition Positions
The vehicle has an electronic keyless
ignition with pushbutton start.
The Remote Keyless Entry (RKE)
transmitter must be in the vehicle for
the system to operate. If the
pushbutton start is not working, the
vehicle may be near a strong radio
antenna signal causing interference to
the Keyless Access system. See Remote
Keyless Entry (RKE) System Operation
0 29.
To shift out of P (Park), the ignition
must be on and the brake pedal must
be applied. Stopping the Engine/OFF (No
Indicator Lights) :
When the vehicle
is stopped, press ENGINE START/
STOP once to turn the engine off.
If the vehicle is in P (Park), the
ignition will turn off, and Retained
Accessory Power (RAP) will remain
active. See Retained Accessory Power
(RAP) 0206.
If the vehicle is in R (Reverse),
D (Drive), or M (Manual Mode), the
vehicle will shift to P (Park), the
ignition will turn off, and RAP will
remain active.
If the vehicle is in N (Neutral), the
ignition will return to ACC/
ACCESSORY and display the message
SHIFT TO PARK in the Driver
Information Center (DIC). When the
vehicle is shifted into P (Park), the
ignition will turn off.
Do not turn the engine off when the
vehicle is moving. This will cause a
loss of power assist in the brake and
steering systems and disable the
airbags.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
218 DRIVING AND OPERATING
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 0143 and
Service Electric Parking Brake Light
0 143. 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 0143.
If the
8light is on, press the EPB
switch and hold it. Continue to
hold the switch until the
Yor PARK light remains on. If
the
8light remains on, see your
dealer.
If the EPB is applied while the vehicle
is moving, the vehicle will decelerate
as long as the switch is pressed. If the
switch is pressed until the vehicle
comes to a stop, the EPB will remain
applied.
The vehicle may automatically apply
the EPB in some situations when the
vehicle is not moving. This is normal,
and is done to periodically check the
correct operation of the EPB system.
If the EPB fails to apply, block the rear
wheels to prevent vehicle movement.
EPB Release
To release the EPB:
1. Turn the ignition on or to ACC/ ACCESSORY.
2. Apply and hold the brake pedal.
3. Press the EPB switch momentarily.
The EPB is released when the
Yor
PARK light is off.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
DRIVING AND OPERATING 221
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. SeeIf the
Vehicle Is Stuck 0196 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.
If
dcomes on and stays on, the
vehicle may need more time to
diagnose the problem. If the condition
persists, see your dealer.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
DRIVING AND OPERATING 287
Trailer tires deteriorate over time. The
trailer tire sidewall will show the week
and year the tire was manufactured.
Many trailer tire manufacturers
recommend replacing tires more than
six years old.
Overloading is another leading cause
of trailer tire blow-outs. Never load
your trailer with more weight than the
tires are designed to support. The load
rating is located on the trailer tire
sidewall.
Always know the maximum speed
rating for the trailer tires before
driving. This may be significantly
lower than the vehicle tire speed
rating. The speed rating may be on
the trailer tire sidewall. If the speed
rating is not shown, the default trailer
tire speed rating is 105 km/h
(65 mph).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) 0139.
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 094 and
Adding Equipment to the
Airbag-Equipped Vehicle 094.

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
288 VEHICLE CARE
Vehicle Care
General Information
General Information . . . . . . . . . . . . . 289
California Proposition65 Warning . . . . . . . . . . . . . . . . . . . . . 289
California Perchlorate Materials Requirements . . . . . . . . . . . . . . . . . . . 290
Accessories and Modifications . . . . . . . . . . . . . . . . . . . 290
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . . . . . . 290
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . . . . . . 292
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . 299
Engine Oil Life System . . . . . . . . . . . 302
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303
Engine Air Filter Life System . . . . 304
Engine Air Cleaner/Filter . . . . . . . . . 304
Cooling System . . . . . . . . . . . . . . . . . . . 307
Engine Overheating . . . . . . . . . . . . . . 312
Washer Fluid . . . . . . . . . . . . . . . . . . . . . 313
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314
Brake Pad Life System . . . . . . . . . . . 315
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . 315 Battery - North America . . . . . . . . . 316
All-Wheel Drive . . . . . . . . . . . . . . . . . . 317
Starter Switch Check . . . . . . . . . . . . . 318
Park Brake and P (Park)
Mechanism Check . . . . . . . . . . . . . . 318
Wiper Blade Replacement . . . . . . . 319
Windshield Replacement . . . . . . . . 319
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . 320
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . . . . . 321
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . 321
LED Lighting . . . . . . . . . . . . . . . . . . . . . 321
Electrical System
Electrical System Overload . . . . . . 322
Fuses and Circuit Breakers . . . . . . 322
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
Instrument Panel Fuse Block . . . . 330
Rear Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339
All-Season Tires . . . . . . . . . . . . . . . . . . 340
Winter Tires . . . . . . . . . . . . . . . . . . . . . . 340
Low-Profile Tires . . . . . . . . . . . . . . . . . 340
Summer Tires . . . . . . . . . . . . . . . . . . . . 340
Tire Sidewall Labeling . . . . . . . . . . . 341 Tire Designations . . . . . . . . . . . . . . . . . 343
Tire Terminology and
Definitions . . . . . . . . . . . . . . . . . . . . . . 344
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . 346
Tire Pressure for High-Speed Operation . . . . . . . . . . . . . . . . . . . . . . . . 347
Tire Pressure Monitor System . . . 348
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . . . . . . . . 349
Tire Inspection . . . . . . . . . . . . . . . . . . . 353
Tire Rotation . . . . . . . . . . . . . . . . . . . . . 353
When It Is Time for New Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 354
Buying New Tires . . . . . . . . . . . . . . . . 355
Different Size Tires and Wheels . . . . . . . . . . . . . . . . . . . . . . . . . . 356
Uniform Tire Quality Grading . . . 357
Wheel Alignment and Tire Balance . . . . . . . . . . . . . . . . . . . . . . . . . . 358
Wheel Replacement . . . . . . . . . . . . . . 358
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . 359
If a Tire Goes Flat . . . . . . . . . . . . . . . . 359
Tire Changing . . . . . . . . . . . . . . . . . . . . . 361
Compact Spare Tire . . . . . . . . . . . . . . 366Jump Starting
Jump Starting - North America . . . . . . . . . . . . . . . . . . . . . . . . . 367
Towing the Vehicle
Towing the Vehicle . . . . . . . . . . . . . . . 370

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
312 VEHICLE CARE
At the end of the cycle, check the
coolant level in the surge tank and
add coolant if it is low. Turn off the
vehicle, allow the Electronic Control
Module (ECM) to go to sleep, about
2 minutes, and repeat Steps 4-7.
Listen for pump activation and
movement of the control valves while
watching the level of the coolant in
the surge tank. If the tank empties,
turn the ignition off, carefully remove
the surge tank cap, refill to the COLD
FILL mark, and repeat Steps 4-7. The
fill and air removal process will run
for approximately 10 minutes.
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 0135 and
Engine Coolant Temperature Warning
Light 0146. 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 0405.
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-12533370) -
2019 - crc - 1/23/19
VEHICLE CARE 313
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 0292 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)

Cadillac CT6 Owner Manual (GMNA-Localizing-U.S./Canada-12533370) -
2019 - crc - 1/23/19
316 VEHICLE CARE
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
(3.0L Twin Turbo and 3.6L V6 Engines)
0 141 orBrake System Warning Light
(2.0L L4 Turbo and 4.2L Twin Turbo
V8 Engines) 0142.
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 0383. What to Add
Use only GM approved DOT 3 brake
fluid from a clean, sealed container.
See
Recommended Fluids and
Lubricants 0392.
{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.
Battery - North America
The original equipment battery is
maintenance free. Do not remove the
cap and do not add fluid.