check engine CADILLAC CT4 2021 User Guide

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
DRIVING AND OPERATING 207
Track Events and
Competitive Driving
(V-Series Only)
{Danger
High-performance features are
intended for use only on closed
tracks by experienced and qualified
drivers and should not be used on
public roads. High-speed driving,
aggressive cornering, hard braking,
and other high-performance driving
can be dangerous. Improper driver
inputs for the conditions may result
in loss of control of the vehicle,
which could injure or kill you or
others. Always drive safely.
Track events and competitive driving
may affect the vehicle warranty. See
the warranty manual before using the
vehicle for competitive driving.
{Warning
Prior to each track event and again
before returning to public roads,
tighten the wheel nuts with a
torque wrench to the proper torque
specification. Wheel nuts that are
improperly or incorrectly tightened
can cause the wheels to become
loose or come off, resulting in a
crash. See Capacities and
Specifications 0396 for wheel nut
torque specifications.
Caution
Low oil levels can damage the
engine. If using the vehicle for
competitive driving, the engine may
use more oil than it would with
normal use. Check the oil level
often during competitive driving.
Competitive Driving Mode can be
selected. See Driver Mode Control
0 241.
Axle Fluid
Axles must have 2400 km (1500 mi)
before being used in track driving.
The rear axle fluid temperatures may
be higher than when driving in severe
conditions. Drain and refill with new
fluid after the first racing or
competitive driving event, and then
after every 24 hours of racing or
competitive driving. See Recommended
Fluids and Lubricants 0391.
Caution
During a first time track or racing
event, high axle temperatures can
occur. Damage could be caused to
the axle and would not be covered
by the vehicle warranty. Do not
drive as long or as fast the first
time the vehicle is driven on the
track or raced.
.The axle lubricant should be
replaced with new lubricant.
.Additional cooling capacity is also
required for continuous competitive
driving.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
208 DRIVING AND OPERATING
Engine Oil
Check the oil level often during track
events and competitive driving and
keep the oil level at or near the
upper mark.
Fuel
Use premium unleaded gasoline with
a posted octane rating of 93 at a track
event. Unleaded gasoline with a
posted octane rating of 91 may be
used, but performance will be
degraded.
Automatic Transmission Fluid
Have the transmission fluid set to the
track specific oil level prior to track
usage. Transmission fluid should be
changed after every 15 hours of track
usage. Any transmission level set or
change should be performed at your
dealer.
Brakes
Brake cooling can be improved if the
front brake disc splash shield and
front tire deflector are removed.
Removing the shield will require that
the suspension bushings and wheelspeed wires visible to the brake disc
be protected with insulated thermal
wrapping.
Caution
Removing the splash shield can
degrade wet braking performance,
as well as introduce brake pedal
pulsation, due to brake disc
exposure to road debris. Only
remove the front brake disc splash
shield and front tire deflector when
driving in track events.
Brake Pad Wear Sensors
(V-Series Only)
If equipped, the brake pad wear
sensors need to be removed from the
brake calipers prior to any track or
racing event. The original sensors can
be reinstalled if significant brake pad
wear is not observed. The sensor
should not extend beyond the brake
pad surface at the rotor contact.
If this condition is observed, the brake
pad life system needs to be disabled
until a new set of brake pads and
sensors are installed and the system
reset. Brake Fluid
.Before racing, replace existing brake
fluid with a qualified racing brake
fluid from a sealed container. Brake
fluid with a dry boiling point
>279 °C (534 °F) is qualified.
If racing brake fluid is used, replace
it with GM approved brake fluid
before driving on public roads. See
Recommended Fluids and Lubricants
0
391.
.Do not use silicone-based fluids.
If racing brake fluid is in the vehicle
and the age of the brake fluid is over a
month old or unknown, replace the
brake fluid between racing/closed
track driving.
Caution
Failure to change the brake fluid
and transfer case fluid after any
performance or race track driving
could result in damage not covered
by the vehicle warranty. Have the
brake fluid and transfer case fluid
changed by your dealer after any (Continued)

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
212 DRIVING AND OPERATING
{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 enoughand 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.
{Warning
Coasting downhill in N (Neutral) or
with the ignition off is dangerous.
This can cause overheating of the
brakes and loss of steering assist.
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.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
218 DRIVING AND OPERATING
Starting and Operating
New Vehicle Break-In
Follow these recommended guidelines
during the first 2 400 km (1,500 mi) of
driving this vehicle. Parts have a
break-in period and performance will
be better in the long run.
For the first 2 400 km (1,500 mi):
.Avoid full throttle starts and abrupt
stops.
.Do not exceed 4000 engine rpm.
.Avoid driving at any one constant
speed, fast or slow.
.Avoid downshifting to brake or slow
the vehicle when the engine speed
will exceed 4000 rpm.
.Do not let the engine labor. Never
lug the engine in high gear at low
speeds.
.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.
Composite Materials
This vehicle may be equipped with
parts containing carbon fiber,
sheet-molding compound, or other
composite materials. Dealer-installed
accessories may also contain
composite materials.
{Warning
Exposed edges of parts containing
carbon fiber and other composite
materials can be sharp. Contact
with these parts could result in
injury. Use caution to avoid
contacting these parts, including
when washing the vehicle. If the
parts are damaged, replace the
parts promptly with replacements
from your dealer.
{Warning
Rocker extensions may break under
pressure, resulting in property
damage or injury. Do not stand on
the rocker extension or use it as
a step.
{Warning
Rear end spoilers may break under
pressure, resulting in property
damage or injury. Do not push the
vehicle by the spoiler or use the
spoiler as a handle.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
222 DRIVING AND OPERATING
To maintain vehicle performance,
other conditions may cause the engine
to automatically restart before the
brake pedal is released.
Auto Stops may not occur and/or Auto
Starts may occur because:
.The climate control settings require
the engine to be running to cool or
heat the vehicle interior.
.The vehicle battery needs to charge.
.The vehicle battery has recently
been disconnected.
.Minimum vehicle speed has not
been reached since the last
Auto Stop.
.The accelerator pedal is pressed.
.The engine or transmission is not at
the required operating temperature.
.The outside temperature is not in
the required operating range.
.The vehicle transmission is shifted
out of D (Drive) to any gear other
than P (Park).
.Certain driver modes have been
selected. SeeDriver Mode Control
0 241.
.The vehicle is on a steep hill or
grade.
.The driver door has been opened or
the 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
feature can be disabled and enabled
by pressing the switch with the
h
symbol. Auto Stop is enabled each
time you start the vehicle.
When
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 engine 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).
The engine heater cord requires the
front license plate mounting bracket
to be installed. See your dealer for
more information.
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.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
226 DRIVING AND OPERATING
To shift out of P (Park):1. Ensure the engine is running.
2. Apply the brake pedal.
3. Press and hold the shift lock release button on the shift lever.
4. Move the shift lever to the desired position. For N (Neutral) hold the
lever in the N (Neutral) position
until the N indicator
illuminates red.
5. The P indicator will turn white and the gear indicator will turn red
when the vehicle is no longer in
P (Park).
6. After releasing the shift lever, it will return to the center position.
If the vehicle cannot shift from
P (Park), a Driver Information Center
(DIC) message may be displayed.
Check that the ignition is on, the
engine is running, the brake pedal is
applied, and the shift lock release
button is pressed when you are
attempting to shift out of P (Park).
If all of these are met but the vehicle
will not shift out of P (Park), see your
dealer for service.Parking over Things
That Burn
{Warning
Things that can burn could touch
hot exhaust parts under the vehicle
and ignite. Do not park over papers,
leaves, dry grass, or other things
that can burn.
Extended Parking
It is best not to park with the vehicle
running. If the vehicle is left running,
be sure it will not move and there is
adequate ventilation.
See Shifting Into Park (Mechanical
Shifter) 0223 or
Shifting Into Park (Electronic Shifter)
0 224 and
Engine Exhaust 0226.
If the vehicle is left parked and
running with the remote key outside
the vehicle, it will continue to run for
up to 15 minutes. If the vehicle is left parked and
running with the remote key inside
the vehicle, it will continue to run for
up to 30 minutes.
The vehicle could turn off sooner if it
is parked on a hill, due to lack of
available fuel.
The timer will reset if the vehicle is
taken out of P (Park) while it is
running.Engine Exhaust
{
Warning
Engine exhaust contains carbon
monoxide (CO), which cannot be
seen or smelled. Exposure to CO
can cause unconsciousness and
even death.
Exhaust may enter the vehicle if:
.The vehicle idles in areas with
poor ventilation (parking garages,
tunnels, deep snow that may
block underbody airf low or tail
pipes). (Continued)

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
DRIVING AND OPERATING 231
To shift in and out of P (Park), see
Shifting Into Park (Mechanical Shifter)
0223 or
Shifting Into Park (Electronic Shifter)
0 224 and
Shifting out of Park (Mechanical Shifter)
0 225 or
Shifting out of Park (Electronic Shifter)
0 225.
Service Shift Lever Message
If the message SERVICE SHIFTER SEE
OWNER’S MANUAL appears in the
Driver Information Center (DIC), the
shift lever needs service. Have the
vehicle serviced as soon as possible.
If the vehicle is automatically shifting
into P (Park), check to see if the
P (Park) button on top of the shift
lever is stuck. To operate the vehicle,
hold the shift lever in the desired gear,
R (Reverse) or D (Drive), until vehicle
speed exceeds 15 km/h (10 mph), then
release the shift lever.
R : Use this gear to back up.
If the vehicle is shifted from either
R (Reverse) to D (Drive), or D (Drive)
or M (Manual Mode) to R (Reverse)
while the speed is too high, the vehicle will shift to N (Neutral).
Reduce the vehicle speed and try the
shift again.
To shift into R (Reverse):
1. Bring the vehicle to a complete stop.
2. Press and hold shift lock release button on the side of the shift
lever.
3. From the center position, move the shift lever forward through the first
detent to the end of travel. R is
illuminated in red.
4. After releasing the shift lever, it will return to the center position.
To shift out of R (Reverse): 1. Bring the vehicle to a complete stop.
2. Shift to the desired gear.
3. After releasing the shift lever, it will return to the center position.
At low vehicle speeds, R (Reverse) can
be used to rock the vehicle back and
forth to get out of snow, ice, or sand
without damaging the transmission.
See If the Vehicle Is Stuck 0214. N :
In this position, the engine does
not connect with the wheels. To
restart the engine when the vehicle is
already moving, use N (Neutral) only.
{Warning
Shifting into a drive gear while the
engine is running at high speed is
dangerous. Unless your foot is
firmly on the brake pedal, the
vehicle could move very rapidly.
You could lose control and hit
people or objects. Do not shift into
a drive gear while the engine is
running at high speed.
Caution
Shifting out of P (Park) or
N (Neutral) with the engine running
at high speed may damage the
transmission. The repairs would not
be covered by the vehicle warranty.
Be sure the engine is not running at
high speed when shifting the
vehicle.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
240 DRIVING AND OPERATING
braking pressure at any one of the
vehicle's brakes to help steer the
vehicle in the intended direction.
If cruise control is being used and TCS
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 0214 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 may display 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.
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.
Turning the Systems Off and On
Caution
Do not repeatedly brake or
accelerate heavily when TCS is off.
The vehicle driveline could be
damaged.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
300 DRIVING AND OPERATING
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 Overheating0322.
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, gradually release the brake
pedal to allow the chocks to absorb
the load of the trailer.
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 0380. 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.
Engine Cooling when Trailer
Towing
The cooling system may temporarily
overheat during severe operating
conditions. See
Engine Overheating
0 322.
Trailer Towing (LSY 2.0L L4
Engine)
Caution
Towing a trailer improperly can
damage the vehicle and result in
costly repairs not covered by the
vehicle warranty. To tow a trailer
correctly, follow the directions in
this section and see your dealer for
important information about
towing a trailer with the vehicle.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
DRIVING AND OPERATING 303
Trailer Brakes
Loaded trailers over 450 kg (1,000 lb)
must be equipped with brake systems
and with brakes for each axle. Trailer
braking equipment conforming to
Canadian Standards Association (CSA)
requirement CAN3-D313, or its
equivalent, is recommended.
State or local regulations may require
trailers to have their own braking
system if the loaded weight of the
trailer exceeds certain minimums that
can vary from state to state. Read and
follow the instructions for the trailer
brakes so they are installed, adjusted,
and maintained properly. Never
attempt to tap into your vehicle's
hydraulic brake system. If you do,
both the vehicle anti-lock brakes and
the trailer brakes may not function,
which could result in a crash.
Trailer Lamps
Always check all trailer lamps are
working at the beginning of each trip,
and periodically on longer trips.
Turn Signals When Towing a
Trailer
When properly connected, the trailer
turn signals will illuminate to indicate
the vehicle is turning, changing lanes,
or stopping. When towing a trailer,
the arrows on the instrument cluster
will illuminate even if the trailer is not
properly connected or the bulbs are
burned out.
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) 097.
A device connected to the DLC —
such as an aftermarket fleet or
driver-behavior tracking device —
(Continued)
Warning (Continued)
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 057 and
Adding Equipment to the
Airbag-Equipped Vehicle 058.