service CADILLAC CT4 2021 Workshop Manual

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
DRIVING AND OPERATING 213
.Be alert on top of hills; something
could be in your lane (e.g., stalled
car, crash).
.Pay attention to special road signs
(e.g., falling rocks area, winding
roads, long grades, passing or
no-passing zones) and take
appropriate action.
Winter Driving
Driving on Snow or Ice
Snow or ice between the tires and the
road creates less traction or grip, so
drive carefully. Wet ice can occur at
about 0 °C (32 °F) when freezing rain
begins to fall. Avoid driving on wet ice
or in freezing rain until roads can be
treated.
For slippery road driving:
.Accelerate gently. Accelerating too
quickly causes the wheels to spin
and makes the surface under the
tires slick.
.Turn on Traction Control. See
Traction Control/Electronic Stability
Control0239.
.Antilock Brake System (ABS)
improves vehicle stability during
hard stops, but the brakes should be
applied sooner than when on dry
pavement. See Antilock Brake System
(ABS) 0236.
See Driver Mode Control 0241.
.Allow greater following distance and
watch for slippery spots. Icy patches
can occur on otherwise clear roads
in shaded areas. The surface of a
curve or an overpass can remain icy
when the surrounding roads are
clear. Avoid sudden steering
maneuvers and braking while
on ice.
.Turn off cruise control.
Blizzard Conditions
Stop the vehicle in a safe place and
signal for help. Stay with the vehicle
unless there is help nearby. If possible,
use Roadside Service. See Roadside
Service 0403. To get help and keep
everyone in the vehicle safe:
.Turn on the hazard warning
flashers.
.Tie a red cloth to an outside mirror.
{Warning
Snow can trap engine exhaust
under the vehicle. This may cause
exhaust gases to get inside. Engine
exhaust contains carbon monoxide
(CO), which cannot be seen or
smelled. It can cause
unconsciousness and even death.
If the vehicle is stuck in snow:
.Clear snow from the base of the
vehicle, especially any blocking
the exhaust pipe.
.Open a window about 5 cm (2 in)
on the vehicle side that is away
from the wind, to bring in
fresh air.
.Fully open the air outlets on or
under the instrument panel.
.Adjust the climate control
system to circulate the air inside
the vehicle and set the fan speed
to the highest setting. See
“Climate Control Systems.”
For more information about CO, see
Engine Exhaust 0226.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
DRIVING AND OPERATING 219
Ignition Positions
The vehicle has an electronic keyless
ignition with pushbutton start.
The remote key 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. SeeRemote
Keyless Entry (RKE) System Operation
0 7.
To shift out of P (Park), the vehicle
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) 0223.
If the vehicle is not in P (Park), the
ignition will return to ACC/
ACCESSORY and display a message in
the Driver Information Center (DIC).
When the vehicle is shifted into
P (Park), the ignition system will
switch to OFF.
The vehicle may have an electric
steering column lock. The lock is
activated when the vehicle is switched
to OFF and the driver door is opened.
A sound may be heard as the lock
actuates or releases. The steering
column lock may not release with the
wheels turned off center. If this
happens, the vehicle may not start.
Move the steering wheel from left to
right while attempting to start the
vehicle. If this does not work, the
vehicle needs service. 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.
If the vehicle must be shut off in an
emergency:
1. Brake using a firm and steady pressure. Do not pump the brakes
repeatedly. This may deplete power
assist, requiring increased brake
pedal force.
2. Shift the vehicle to N (Neutral). This can be done while the vehicle
is moving. After shifting to
N (Neutral), firmly apply the brakes
and steer the vehicle to a safe
location.
3. Come to a complete stop, shift to P (Park), and turn the ignition to
OFF. On vehicles with an automatic
transmission, the shift lever must
be in P (Park) to turn the ignition
switch to the OFF position.
4. Set the parking brake. See Electric
Parking Brake 0237.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
220 DRIVING AND OPERATING
{Warning
Turning off the vehicle while
moving may cause loss of power
assist in the brake and steering
systems and disable the airbags.
While driving, only shut the vehicle
off in an emergency.
If the vehicle cannot be pulled over,
and must be shut off while driving,
press and hold the ENGINE START/
STOP button for longer than
two seconds, or press twice in
five seconds.
ACC/ACCESSORY (Amber Indicator
Light) : This mode allows you to use
some electrical accessories when the
engine is off.
With the ignition off, pressing the
button one time without the brake
pedal applied will place the ignition
system in ACC/ACCESSORY.
The ignition will switch from ACC/
ACCESSORY to OFF after five minutes
to prevent battery rundown. ON/RUN/START (Green Indicator
Light) :
This mode is for driving and
starting. With the ignition off, and the
brake pedal applied, pressing the
button once will place the ignition
system in ON/RUN/START. Once
engine cranking begins, release the
button. Engine cranking will continue
until the engine starts. See Starting the
Engine 0220. The vehicle will then
remain on.
Service Mode
This power mode is available for
service and diagnostics, and to verify
the proper operation of the
malfunction indicator lamp as may be
required for emission inspection
purposes. With the vehicle off, and the
brake pedal not applied, pressing and
holding the button for more than
five seconds will place the vehicle in
Service Mode. The instruments and
audio systems will operate as they do
in ON/RUN, but the vehicle will not be
able to be driven. The engine will not
start in Service Mode. Press the
button again to turn the vehicle off.
Starting the Engine
Place the transmission in the
proper gear
Caution
If you add electrical parts or
accessories, you could change the
way the engine operates. Any
resulting damage would not be
covered by the vehicle warranty. See
Add-On Electrical Equipment 0303.
Move the shift lever to P (Park) or
N (Neutral). To restart the vehicle
when it is already moving, use
N (Neutral) only.
Caution
Do not try to shift to P (Park) if the
vehicle is moving. If you do, you
could damage the transmission.
Shift to P (Park) only when the
vehicle is stopped.
Starting the Vehicle 1. Press the brake pedal, then press ENGINE START/STOP on the
instrument panel.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
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DRIVING AND OPERATING 225
Leaving the Vehicle with the
Engine Running
{Warning
It can be dangerous to leave the
vehicle with the engine running.
It could overheat and catch fire.
It is dangerous to get out of the
vehicle if the vehicle is not in
P (Park) with the parking brake set.
The vehicle can roll.
Do not leave the vehicle when the
engine is running. If you have left
the engine running, the vehicle can
move suddenly. You or others could
be injured. To be sure the vehicle
will not move, even when you are
on fairly level ground, always set
the parking brake and shift to
P (Park). SeeShifting Into Park
(Mechanical Shifter) 0223 or
Shifting Into Park (Electronic Shifter)
0 224. If you are towing a trailer,
see Driving Characteristics and
Towing Tips 0297. If you have to leave the vehicle with
the engine running, be sure the
vehicle is in P (Park) and the parking
brake is set before you leave it.
If you are towing a trailer and parking
on a hill, see
Driving Characteristics
and Towing Tips 0297.
Shifting out of Park
(Mechanical Shifter)
This vehicle is equipped with an
electronic shift lock release system.
The shift lock release is designed to
prevent movement of the shift lever
out of P (Park), unless the ignition is
on and the brake pedal is applied.
The shift lock release is always
functional except in the case of an
uncharged or low voltage (less than
9 volt) battery.
If the vehicle has an uncharged
battery or a battery with low voltage,
try charging or jump starting the
battery. See Jump Starting - North
America 0366 for more information. To shift out of P (Park):
1. Apply the brake pedal.
2. Release the parking brake. See Electric Parking Brake 0237.
3. Press the shift lever button.
4. Move the shift lever.
If unable to shift out of P (Park): 1. Fully release the shift lever button.
2. While holding down the brake pedal, press the shift lever button
again.
3. Move the shift lever.
If the shift lever will not move from
P (Park), consult your dealer or a
professional towing service.
Shifting out of Park
(Electronic Shifter)
This vehicle is equipped with an
electronic transmission. The shift lock
release button is designed to prevent
inadvertent shifting out of P (Park).

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) -
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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) -
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DRIVING AND OPERATING 237
that vehicle suddenly slows or stops.
Always leave enough room ahead to
stop, even with ABS.
Using ABS
Do not pump the brakes. Just hold the
brake pedal down firmly. Hearing and
feeling ABS operate is normal.
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 Electric Parking Brake (EPB) can
always be applied, even if the vehicle
is off. In case of insufficient electrical
power, the EPB cannot be applied or
released. To prevent draining the
battery, avoid unnecessary repeated
cycles of the EPB.
The system has a red parking brake
status light and an amber service
parking brake warning light. See
Electric Parking Brake Light0100 and
Service Electric Parking Brake Light
0 100. There are also parking
brake-related Driver Information
Center (DIC) messages.
Before leaving the vehicle, check the
red parking brake status 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 red parking brake status light will
flash and then stay on once the EPB is
fully applied. If the red parking brake status 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 red parking
brake status light is flashing. See your
dealer.
If the amber service parking brake
warning light is on, press the EPB
switch. Continue to hold the switch
until the red parking brake status light
remains on. If the amber service
parking brake warning light is 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

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
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238 DRIVING AND OPERATING
correct operation of the EPB system,
or at the request of other safety
functions that utilize the EPB.
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 red
parking brake status light is off.
If the amber service parking brake
warning light is on, release the EPB by
pressing and holding the EPB switch.
Continue to hold the switch until the
red parking brake status light is off.
If either light stays on after release is
attempted, see your dealer.
Caution
Driving with the parking brake on
can overheat the brake system and
cause premature wear or damage to (Continued)
Caution (Continued)
brake system parts. Make sure that
the parking brake is fully released
and the brake warning light is off
before driving.
If you are towing a trailer and parking
on a hill, see Driving Characteristics
and Towing Tips 0297.
Automatic EPB Release
The EPB will automatically release if
the vehicle is running, placed into
gear, and an attempt is made to drive
away. Avoid rapid acceleration when
the EPB is applied, to preserve parking
brake lining life.
Brake Assist
Brake Assist detects rapid brake pedal
applications due to emergency braking
situations and provides additional
braking to activate the Antilock Brake
System (ABS) if the brake pedal is not
pushed hard enough to activate ABS
normally. Minor noise, brake pedal
pulsation, and/or pedal movement
during this time may occur. Continue
to apply the brake pedal as the driving situation dictates. Brake Assist
disengages when the brake pedal is
released.
Hill Start Assist (HSA)
{Warning
Do not rely on the HSA feature.
HSA does not replace the need to
pay attention and drive safely. You
may not hear or feel alerts or
warnings provided by this system.
Failure to use proper care when
driving may result in injury, death,
or vehicle damage. See
Defensive
Driving 0204.
When the vehicle is stopped on a
grade, Hill Start Assist (HSA)
temporarily prevents the vehicle from
rolling in an unintended direction
during the transition from brake pedal
release to accelerator pedal apply. The
brakes release when the accelerator
pedal is applied or automatically
release after a few seconds. The brakes
may also release under other
conditions. Do not rely on HSA to
hold the vehicle.

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
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DRIVING AND OPERATING 259
guardrails, and other stationary
objects when entering or exiting a
curve. This is normal operation. The
vehicle does not need service.
Other Vehicle Lane Changes
ACC will not detect a vehicle ahead
until it is completely in the lane. The
brakes may need to be manually
applied.
Objects Not Directly in Front of Your
Vehicle
The detection of objects in front of
the vehicle may not be possible if:
.The vehicle or object ahead is not
within your lane.
.The vehicle ahead is shifted, not
centered, or is shifted to one side of
the lane.Driving in Narrow Lanes
Vehicles in adjacent traffic lanes or
roadside objects may be incorrectly
detected when located along the
roadway.
Do Not Use ACC on Hills and When
Towing a Trailer
Do not use ACC when driving on steep
hills or when towing a trailer. ACC will
not detect a vehicle in the lane while
driving on steep hills. If the brakes are
applied, ACC disengages.
Disengaging ACC
There are three ways to
disengage ACC:
.Step lightly on the brake pedal.
.Press*.
.PressJ.Erasing Speed Memory
The ACC set speed is erased from
memory if
Jis pressed or if the
ignition is turned off.
Weather Conditions Affecting ACC
System operation may be limited
under snow, heavy rain, or road spray
conditions.
Accessory Installations and Vehicle
Modifications
Do not install or place any object
around the front camera windshield
area that would obstruct the front
camera view.
Do not install objects on top of the
vehicle that overhang and obstruct the
front camera, such as a canoe, kayak,
or other items.
Do not modify the hood, headlamps,
or fog lamps, as this may limit the
camera’s ability to detect an object.
Cleaning the Sensing System
The camera sensor on the windshield
behind the rearview mirror and the
radar sensors on the front of the
vehicle can become blocked by snow,

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
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260 DRIVING AND OPERATING
ice, dirt, or mud. These areas need to
be cleaned for ACC to operate
properly.
If ACC will not operate, regular Cruise
Control may be available. See
“Switching Between ACC and Regular
Cruise Control”previously in this
section. Always consider driving
conditions before using either cruise
control system.
For cleaning instructions, see
“Washing the Vehicle ”under Exterior
Care 0370.
System operation may also be limited
under snow, heavy rain, or road spray
conditions.
Super Cruise
If equipped, Super Cruise can steer to
maintain lane position under certain
conditions on Super Cruise-enabled
roads that are separated from
opposing traffic.
Super Cruise can also steer to perform
a lane change under certain
conditions on Super Cruise-enabled
roads when a lane change is initiated
by the driver using the turn signal lever. See
“Super Cruise Lane Change ”
later in this section and Turn and
Lane-Change Signals 0129.
{Warning
Super Cruise can only assist to
maintain lane position, or steer to
change lanes, when driving on
compatible roads. You must
supervise the driving task and
monitor the road conditions. You
may need to respond to traffic
events by steering, braking,
or accelerating. See Defensive
Driving.
Super Cruise is:
.Not a self-driving system
.Not a crash avoidance or warning
system
.Not a substitute for proper
supervision of the driving task.
Super Cruise uses the following to
detect the current lane position and
lane markings ahead on compatible
roads under certain conditions:
.Cameras
.Global Positioning System (GPS)
sensing
.A high-precision map
.GPS-enhancement data downloaded
through Connected Services
Super Cruise works with Adaptive
Cruise Control (ACC), which controls
acceleration and braking while Super
Cruise is enabled and operating.
Review and understand both this
section and the ACC section before
using Super Cruise. See Adaptive
Cruise Control (Advanced) 0251.
An active Super Cruise service plan is
required to use Super Cruise.
{Warning
Super Cruise does not perform all
aspects of driving, nor does it do
everything a driver can do. Super
Cruise only steers to maintain
vehicle position in the current lane
or, under some circumstances, to
change lanes. Super Cruise can only
be used with Adaptive Cruise
Control. (Continued)