2021 CADILLAC CT4 brake light

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
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 239
HSA is available when the vehicle is
facing uphill in a forward gear,
or when facing downhill in
R (Reverse). The vehicle must come to
a complete stop on a grade for HSA to
activate.
Automatic Vehicle
Hold (AVH)
{Warning
Do not rely on this feature. It does
not replace the need to pay
attention and drive safely. You may
not hear or feel alerts or warnings(Continued)
Warning (Continued)
provided by this system. Failure to
use proper care when driving may
result in injury, death, or vehicle
damage.
When Automatic Vehicle Hold (AVH)
is turned on and the vehicle is braked
to a stop, AVH prevents the vehicle
from moving during the transition
from brake pedal release to accelerator
pedal apply. The brakes release when
the accelerator pedal is applied. The
brakes may also release under other
conditions. Do not rely on AVH to
hold the vehicle.
If the accelerator pedal is not applied
within a few minutes, the Electric
Parking Brake will apply. The parking
brake will also apply if the driver door
is opened or the driver seat belt is
unfastened while AVH is holding the
vehicle.
AVH can be turned on by pressing
AUTO HOLD. The indicator light on
the switch will come on. The AVH
light on the instrument panel will come on while AVH is actively holding
the vehicle. See
Automatic Vehicle Hold
(AVH) Light 0101.
Ride Control Systems
Traction Control/Electronic
Stability Control
The vehicle has a Traction Control
System (TCS) and StabiliTrak/
Electronic Stability Control (ESC).
These systems help limit wheel slip
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, the system brakes the
spinning wheel(s) and/or reduces
engine power to limit wheel spin.
StabiliTrak/ESC activates when the
computer senses a difference between
the intended path and the direction
the vehicle is actually traveling.
StabiliTrak/ESC selectively applies

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.

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DRIVING AND OPERATING 245
hold lower gears when not using
paddles. The shifts are also firmer to
increase the quickness of shifting.
Engine Sound
Adjusts the volume of engine noise.
The sound level changes when the
variable exhaust valves open.
Steering (Assist Effort)
Adjusts from a lighter steering feel in
Tour Mode to reduced assist in Sport
and Track Mode for more
steering feel.
Magnetic Ride Control (If Equipped)
Adjusts the shock dampening
firmness from a comfort in Tour Mode
to an optimized responsiveness tune
in Sport and Track.
Stability Control
.Competitive Mode allows less
computer control to permit some
slide and drift and is selected with
the TCS/StabiliTrak button–only
available in Sport Mode.
.StabiliTrak/Electronic Stability
Control (ESC) can be turned off by
pressing and holding the TCS/
StabiliTrak button for five seconds.
Brake Response
Adjusts brake pedal sensitivity by
selecting how quick or slow the brakes
respond to input.
Driver Mode Customization
The following settings can be changed
using the Driver Mode Customization
Menu. See “Settings>Vehicle>Drive
Mode Customization ”in the center
stack to customize My Mode or
V-Mode.
Engine Sound
Engine sound adjusts the volume of
engine noise. The settings range from
quietest to loudest volume from
Stealth through Track.
–Stealth, Tour, Sport, Track Steering
Steering adjusts the effort required to
turn the steering wheel. The steering
wheel offers better feedback in the
Tour setting, but requires more effort
in the Sport and Track settings.
–Tour, Sport, Track
Suspension
Suspension adjusts the firmness of the
suspension in the vehicle. Suspension
adjusts the stiffness of the shocks and
/ or springs. The ride is more
comfortable at lower settings and is
stiffer at higher settings for better
control.
–Tour, Sport, Track
Powertrain
Powertrain adjusts the throttle
response, gear shifting and engine
performance. Throttle response
increases in the Sport, Track, and
Snow/Ice settings, and gear shifting is
more aggressive.
–Tour, Sport, Track, Snow/Ice

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
2021 - CRC - 12/4/20
246 DRIVING AND OPERATING
Brake Response
Brake Response adjusts the brake
pedal response. Settings range from a
slower response for more comfortable
driving to the quickest response for
quicker deceleration. Brake pedal
travel decreases and caliper pressure
increases in the Sport and Track
settings.
–Tour, Sport, Track
PTM (Performance Traction
Management)
PTM controls vehicle performance
systems for professional handling on
race tracks. Traction Control and
Stability Control are reduced as you
move through each of the settings.
Changing PTM settings may also
automatically change the other
subsystem settings. See“Performance
Traction Management ”in Competitive
Driving Mode 0246
–Off, Wet, Dry, Sport, Race 1, Race 2Competitive Driving Mode
To select this optional handling mode,
press
Yquickly two times and the
DIC will display COMPETITIVE MODE
ON. While in the Competitive Driving
Mode, the traction off light
iand
StabiliTrak/ESC OFF light
gwill come
on in the instrument cluster. TCS does
not limit wheel spin, the Electronic
Limited-Slip Differential (eLSD) allows
increased vehicle agility, and more
effort is required to turn the steering
wheel. See “Limited-Slip Differential
(V–Series Only)” later in this section.
Adjust your driving accordingly.
Press
Yagain, or turn the ignition to
ACC/ACCESSORY and restart the
vehicle, to turn TCS back on. The
traction off light
iand StabiliTrak/
ESC OFF light
gwill go out in the
instrument cluster.
Caution
When traction control is turned off,
or Competitive Driving Mode is
active, it is possible to lose traction.
Performance Traction
Management (PTM)
PTM can be activated through V-Mode
customization or by pressing the ESC
button twice while in Track Mode.
To activate PTM through V-Mode
customization, select the desired PTM
state in the center stack
(Vehicle>Settings>Drive Mode
Customization>V-Mode). Press the
V-Mode button once to activate
V-Mode. When PTM is configured on,
a message will appear in the Driver
Information Center (DIC) “V-Mode
Active - Press Again for PTM On - ESC
May be Disabled”.
To confirm and enter PTM, press the
V-Mode button again. The PTM state
can now be modified using the mode
knob or changing the V-Mode PTM
settings in the center stack. Both the
V–Mode and PTM indicators will be
displayed. To exit PTM, press the ESC
button.
To cancel the PTM request message
and not enter PTM, press the center
dismiss button on the steering wheel
(V–Mode remains active).

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
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DRIVING AND OPERATING 251
Ending Cruise Control
There are four ways to end cruise
control:
.Step lightly on the brake pedal.
.Press*.
.Shift the transmission to
N (Neutral).
.PressJ.
Erasing Speed Memory
The cruise control set speed is erased
from memory if
Jis pressed or if the
ignition is turned off.
Adaptive Cruise Control
(Advanced)
If equipped, Adaptive Cruise Control
(ACC) allows the cruise control set
speed and following gap to be
selected. Read this entire section
before using this system. The
following gap is the following time
between your vehicle and a vehicle
detected directly ahead in your path,
moving in the same direction. If no
vehicle is detected in your path, ACC works like regular cruise control. ACC
uses camera and radar sensors. See
Radio Frequency Statement
0409.
If a vehicle is detected in your path,
ACC can speed up the vehicle or apply
limited, moderate braking to maintain
the selected following gap. To
disengage ACC, apply the brake. If the
Traction Control System (TCS) or
StabiliTrak/Electronic Stability Control
(ESC) system activates while ACC is
engaged, ACC may automatically
disengage. See Traction Control/
Electronic Stability Control 0239. When
road conditions allow ACC to be safely
used, ACC can be turned back on. ACC
will not engage if the TCS or
StabiliTrak/ESC electronic stability
control system is disabled.
ACC can reduce the need for you to
frequently brake and accelerate,
especially when used on expressways,
freeways, and interstate highways.
When used on other roads, you may
need to take over the control of
braking or acceleration more often.
{Warning
ACC has limited braking ability and
may not have time to slow the
vehicle down enough to avoid a
collision with another vehicle you
are following. This can occur when
vehicles suddenly slow or stop
ahead, or enter your lane. Also see
“Alerting the Driver” in this section.
Complete attention is always
required while driving and you
should be ready to take action and
apply the brakes. See Defensive
Driving 0204.
{Warning
ACC will not detect or brake for
children, pedestrians, animals,
or other objects.
Do not use ACC when:
.On winding and hilly roads or
when the sensors are blocked by
snow, ice, or dirt. The system
(Continued)

Cadillac CT4 Owner Manual (GMNA-Localizing-U.S./Canada-14584335) -
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DRIVING AND OPERATING 257
.Objects that are close to the front of
your vehicle.
ACC Automatically Disengages
ACC may automatically disengage and
you will need to manually apply the
brakes to slow the vehicle when:
.The sensors are blocked.
.The Traction Control System (TCS)
or StabiliTrak/ESC system has
activated or been disabled.
.There is a fault in the system.
.The radar falsely reports blockage
when driving in a desert or remote
area with no other vehicles or
roadside objects. A DIC message
may display to indicate that ACC is
temporarily unavailable.
The ACC indicator will turn white
when ACC is no longer active.
In some cases, when ACC will not
activate, regular Cruise Control may
be used. See “Switching Between ACC
and Regular Cruise Control ”previously
in this section. Always consider
driving conditions before using either
cruise control system. Notification to Resume ACC
ACC will maintain a follow gap behind
a detected vehicle and slow your
vehicle to a stop behind that vehicle.
If the stopped vehicle ahead has
driven away and ACC has not
resumed, the vehicle ahead indicator
will flash as a reminder to check
traffic ahead before proceeding. In
addition, the left and right sides of the
Safety Alert Seat will pulse three
times, or three beeps will sound. See
“Alert Type
”and “Adaptive Cruise Go
Notifier” in“Collision/Detection
Systems” underVehicle Personalization
0 117.
When the vehicle ahead drives away,
ACC resumes automatically if the stop
was brief. If necessary, press RES+ or
the accelerator pedal to resume ACC.
If stopped for more than two minutes
or if the driver door is opened and the
driver seat belt is unbuckled, the ACC
automatically applies the Electric
Parking Brake (EPB) to hold the
vehicle. The EPB status light will turn
on. See Electric Parking Brake 0237.
To release the EPB, press the
accelerator pedal. A DIC warning message may display
indicating to shift to P (Park) before
exiting the vehicle.
{Warning
If ACC has stopped the vehicle, and
if ACC is disengaged, turned off,
or canceled, the vehicle will no
longer be held at a stop. The vehicle
can move. When ACC is holding the
vehicle at a stop, always be
prepared to manually apply the
brakes.
{Warning
Leaving the vehicle without placing
it in P (Park) can be dangerous. Do
not leave the vehicle while it is
being held at a stop by ACC. Always
place the vehicle in P (Park) and
turn off the ignition before leaving
the vehicle.
ACC Override
If using the accelerator pedal while
ACC is active, the ACC indicator turns
blue on the instrument cluster and in

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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,